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Melioidosis is a disease endemic to India but often goes unrecognized, leading to considerable illness and death. We present the case of a 31-year-old man who had a fever of unknown origin, abnormal renal and liver function tests, and negative tests for dengue, typhoid, leptospirosis, and scrub typhus. Imaging revealed multiple splenic infarcts. Initially suspected to be malaria due to its prevalence in South India, further investigation uncovered pneumonia along with several liver and splenic abscesses, raising the possibility of melioidosis. Blood culture eventually identified Burkholderia pseudomallei , confirming the diagnosis. As malaria cases decline in Southeast Asia, emergency physicians should consider melioidosis in their differential diagnosis of acute febrile illnesses, especially in endemic areas. Early detection and prompt antibiotic treatment are vital for managing this often under-recognized disease with a high fatality rate. Thus, melioidosis should be considered in patients with unexplained fever in endemic regions, as early diagnosis and intervention can be life-saving. [ABSTRACT FROM AUTHOR]

Background: Acute encephalitis (AE) is associated with a high burden of mortality and permanent disability and has a spectrum of underlying etiologies. The prognosis of encephalitis is difficult and almost all the patients seem to be at a high risk of poor outcomes. A number of physiological changes take place during encephalitis and have been evaluated for their prognostic value. Platelet count, which has been recognized as a surrogate prognostic marker in various viral illnesses, has recently been recognized to have a prognostic value in AE too. In the present study, we attempted to study the role of thrombocytopenia in the prognosis of AE. Methods: Total of 98 cases based on clinical, cerebrospinal fluid, and radiological profiles consistent with the diagnosis of AE were enrolled in the study. A clinical profile was noted, and platelet count was assessed. Thrombocytopenia was defined as platelet count <150,000/mm3. Platelet count 100,000–150,000, 50,000–99,999, and <50,000/mm3 were considered mild, moderate, and severe thrombocytopenia. The underlying etiology was explored, and patients were followed till discharge/outcome. The outcome was noted in terms of the Modified Rankin score (MRS). MRS 0–2 was considered good, 3–4 fair, and 5–6 as poor outcome. Results: The mean age of patients was 34.06 ± 18.76 years. Majority of patients were women (54.1%). Prevalence of thrombocytopenia was 75.5%. A total of 34 (45.9%) had mild, 30 (40.5%) had moderate, and 10 (13.5%) had severe thrombocytopenia. Acute viral encephalitis (unclassified) was the most common etiology (33.7%), followed by scrub meningoencephalitis (24.5%) and Japanese encephalitis (12.2%), respectively. Good, fair, and poor outcomes were noted in 48 (49%), 21 (21.4%), and 29 (29.6%) cases. On univariate analysis, no significant association of poor outcome was seen with age, sex, duration of fever, and mechanical ventilation need (P > 0.05). Low Glasgow Coma Scale (GCS), splenomegaly, low platelet count, and Japanese encephalitis virus/scrub typhus etiologies were found to be significantly associated with poor outcomes (P < 0.05). Thrombocytopenia compared to normal platelet count and severe thrombocytopenia compared to mild and moderate thrombocytopenia were significantly associated with poor outcomes (P < 0.05). On multivariate analysis, GCS <8 (odds ratio [OR] =4.52; 95% confidence interval [CI] =1.56–13.20) and thrombocytopenia (OR = 11.92; 95% CI = 1.38–103.32) emerged as independent predictors of poor outcome. Conclusions: The findings of the study showed that low GCS and thrombocytopenia could be used as predictors of poor outcomes in AE cases. [ABSTRACT FROM AUTHOR]

Candidatus Orientia chiloensis causes scrub typhus over a wide geographical range in southern Chile. The life cycle, including vectors and reservoirs of this novel rickettsial pathogen, is incompletely understood. We analyzed rodent tissue and rodent-associated mite samples collected during a field study in six localities on Chiloé Island, where human scrub typhus cases have occurred. Using molecular methods, we detected Orientia DNA in 24.8% of rodents, belonging to five of seven captured species. Orientia-infection rates showed geographical variations, but were not influenced by rodent species, sex, age, and mite infestation. Phylogenetic analysis showed that Orientia sequences from trombiculid mites (Proschoengastia eloisae) were identical to those from scrub typhus patients from the same region. The results suggest that these rodent-associated mites serve as vectors and play an important role in the ecology of scrub typhus in southern Chile. Further studies are required to determine whether Orientia-infected rodents can also serve as reservoir of Orientia in Chile. [ABSTRACT FROM AUTHOR]

A 51-year-old female sanitation worker in China developed bilateral neuroretinitis due to scrub typhus. Initially diagnosed with ‘scrub typhus infected pneumonia’, her symptoms subsided within seven days of chloramphenicol treatment. However, two weeks later, she experienced acute bilateral vision loss. Fundoscopy revealed swollen optic discs, exudates, and a small macular pigment epithelial detachment. Diagnosed with scrub typhus-related neuroretinitis, her vision improved after methylprednisolone treatment. This represents the first reported case of such in southern China, suggesting a delayed immune response to scrub typhus. Early diagnosis and proper treatment are crucial for vision prognosis. [ABSTRACT FROM AUTHOR]

Background: Scrub typhus is a life-threatening zoonotic infection. In recent years, the endemic areas of scrub typhus have been continuously expanding, and the incidence rate has been increasing. However, it remains a globally neglected disease. Yunnan Province is a major infected area, and the study of spatiotemporal and seasonal variation scrub typhus in this region is crucial for the prevention and control of the disease. Methods/Results: We collected surveillance data on scrub typhus cases in Yunnan Province from 2006 to 2022. Using methods such as spatial trend analysis, Moran's I, and retrospective temporal scan statistics, the spatial and seasonal changes of scrub typhus were analyzed. The study period recorded 71,068 reported cases of scrub typhus in Yunnan Province, with the annual incidence rate sharply increasing (P<0.001). Approximately 93.38% of cases are concentrated in June to November (P = 0.001). Nearly 98.0% of counties were affected. The center of gravity of incidence migrates in a south and west direction. The incidence of scrub typhus was positively correlated spatially, and the spatial clustering distribution was significant. The most likely spatial cluster of cases (relative risk = 14.09, P<0.001) was distributed in Lincang, Dehong, Baoshan, Banna, and Puer. Significant positive correlations between the number of scrub typhus cases and average temperature, precipitation and relative humidity. Conclusions: In Yunnan Province, scrub typhus is widely transmitted, with an increasing incidence, and it exhibits distinct seasonal characteristics (from June to November). The center of gravity of incidence has shifted to the south and west, with higher incidence rates observed in border regions. The risk clustering regions encompass all border prefectures. This pattern is significantly correlated with climatic factors such as average temperature, precipitation, and relative humidity. The relevant departments should strengthen the monitoring of scrub typhus, formulate prevention and control strategies, and provide health education to local residents. Author summary: Scrub typhus is an acute infectious disease of natural epidemic origin caused by Orientia tsutsugamushi. Scrub typhus is spread primarily through the bite of a chigger mite larva that carries Orientia tsutsugamushi. It's clinical manifestations mainly include non-specific symptoms such as headache, fever, rash, cough, vomiting, muscle pain, and swollen lymph nodes. It can lead to a variety of complications such as pneumonia, encephalitis, and myocarditis, which can be life-threatening in severe cases. Scrub typhus is prevalent globally in Southeast Asia, the Southwest Pacific Islands, Japan, and China, and is expanding. However, it remains a neglected infectious disease. We aim to understand the temporal and seasonal variations of scrub typhus in Yunnan Province, discover the high prevalence areas of scrub typhus and their seasonal patterns, so as to provide a basis for conducting targeted surveillance and health education in Yunnan Province, especially in high-risk areas. [ABSTRACT FROM AUTHOR]

Chiggers are larval mites that pose a significant health risk globally via the spread of scrub typhus. However, fundamental studies into the bacterial microbiome in North America have never been considered. In this investigation, chiggers were collected in the wild from two locally common rodent host species (i.e., Sigmodon hispidus and Peromyscus leucopus) in three different ecoregions of North Carolina (NC), United States to investigate the composition of their bacterial communities, including potential pathogens. DNA was extracted from the chiggers, and the V3-V4 regions of the bacterial 16S rRNA gene were sequenced using next-generation sequencing (NGS). Alpha diversity metrics revealed significant differences in bacterial diversity among different collection counties. Beta diversity metrics also revealed that bacterial communities across counties were significantly different, suggesting changes in the microbiome as the environment changed. Specifically, we saw that the two western NC collection counties had similar bacterial composition as did the two eastern collection counties. In addition, we found that the chigger microbiome bacterial diversity and composition differed between rodent host species. The 16S rRNA sequence reads were assigned to 64 phyla, 106 orders, 199 families, and 359 genera. The major bacterial phylum was Actinobacteria. The most abundant species were in the genera Corynebacterium, Propionibacterium, class ZB2, and Methylobacterium. Sequences derived from potential pathogens within the genera Orientia and Rickettsia were also detected. Our findings provide the first insights into the ecology of chigger microbiomes in the US. Further research is required to determine if the potential pathogens found detected in chiggers are a threat to humans and wildlife. [ABSTRACT FROM AUTHOR]

Simple Summary: This study examines the relationship between small mammals and the chigger mites (Acari: Trombiculidae) that parasitize them in different habitat types within a region of South Korea. Small mammals are important hosts for chigger mites, which are vectors for diseases such as scrub typhus. We investigated how the distribution of small mammals and their parasitic mites varies across forests, grasslands, agricultural lands, and ecotones. Our findings suggest that grasslands and ecotones near human settlements have the highest abundance of small mammals, particularly Apodemus agrarius, and consequently, higher rates of mite infestation. In particular, the density of A. agrarius increased significantly in the fall, leading to a sharp rise in mite infestation rates and mean intensity. By understanding how habitat characteristics influence the abundance of small mammals and their parasites, this research highlights the importance of habitat management strategies to reduce the spread of mite-borne diseases to humans. While urbanization leads to habitat loss for medium and large mammals, small mammals can survive in fragmented habitats. As they are known to be the primary hosts of chigger mites (Acari: Trombiculidae) that transmit scrub typhus, their habitat can be considered the primary distribution area for chigger mites. This study aims to examine the distribution of small mammals and chigger mites in four habitat types and analyzed species richness, mean intensity (MI), dominance, and infestation rate (IR). A total of six small mammal species were captured, 76.8% of which were identified as Apodemus agrarius. Species richness of small mammals was highest in forests, followed by ecotones, grasslands, and agricultural lands. Apodemus agrarius accounted for 61% of the captures in forests, 80% in ecotones, 84% in grasslands, and 50% in agricultural lands, highlighting its varying dominance across habitat types. The MI of chigger mites was higher in grasslands (215.41 ± 20.70) and ecotones (171.67 ± 30.33) and lower in forests (76.67 ± 32.11). The MI of chigger mites was higher in the fall than that in the spring, and according to the MaxEnt model, they had a narrow, dense distribution in the fall and a wide distribution in the spring. These results suggest that inducing increased species richness of small mammalian hosts by habitat management and vegetation diversification may contribute to a reduction in the MI of chigger mites. [ABSTRACT FROM AUTHOR]

Human granulocytic anaplasmosis (HGA) is a tick-borne infection caused by Anaplasma phagocytophilum. Only seven cases of HGA have been reported in Japan to date. We report the case of a 61-year-old female farmer who developed HGA with rash and rhabdomyolysis. The patient had fever and erythema covering the entire body, including the palms. An induration with an eschar was observed on the right leg, indicating that the patient had been bitten by a tick. Elevated serum creatinine and creatinine kinase levels and hematuria indicated rhabdomyolysis. We suspected Japanese spotted fever, a tick-borne illness caused by Rickettsia Japonica , and administered minocycline and ciprofloxacin for a week. Transient neutropenia and thrombocytopenia were observed, but the symptoms improved. Polymerase chain reaction (PCR) and antibody tests for R. japonica and Orientia tsutsugamushi , which causes scrub typhus, were both negative. The PCR test for severe fever with thrombocytopenia syndrome virus was also negative. Antibodies against A. phagocytophilum –related proteins were detected by western blotting, indicating seroconversion of IgG with paired serum samples, and the patient was diagnosed with HGA. HGA should be suspected in acute febrile patients with a history of outdoor activity and cytopenia, with or without a rash. A testing system and the accumulation of cases in Japan are necessary for the early diagnosis and appropriate treatment of HGA. [ABSTRACT FROM AUTHOR]

Background: Rodents play essential ecological roles but are also significant reservoirs of zoonotic pathogens, posing risks to humans. Individuals with frequent occupational contact with rodents face an elevated risk of exposure to rodent-borne diseases. This study examines the knowledge, risk perceptions, and practices of Chilean environmental consultants (ECs) concerning rodents and rodent-borne diseases. Methods: A 32-item questionnaire, which focused primarily on biologists, veterinarians, and environmental engineers, was administered. The questionnaire included closed, open-ended, and semi-open-ended questions. Data analyses, performed using R software, involved calculating frequencies and proportions for questions related to knowledge of rodents and rodent-borne diseases, rodent management and handling, biosafety procedures, and training. Additionally, generalized linear models (GLMs) were used to assess knowledge of rodent hosts and diseases, whereas correspondence analysis was used to examine associations between EC characteristics (undergraduate fields of study and years of experience) and responses regarding risk perception and the importance of zoonotic disease training. Results: Completed questionnaires were received from 206 ECs. Although the ECs demonstrated a strong awareness of hantavirus cardiopulmonary syndrome, identifying it as a significant rodent-borne threat, knowledge gaps were evident regarding the specific role of certain rodent reservoir species and other rodent-borne diseases in Chile. For example, leptospirosis was well recognized, particularly among veterinarians, whereas emerging zoonoses such as scrub typhus was rarely mentioned. The study also revealed the frequent use of live trapping and direct handling of rodents, resulting in injuries to 32% of the respondents. Despite the widespread use of personal protective equipment, key elements such as respiratory protection and disposable suits were underutilized, and inadequate cleaning practices for traps were reported. Nevertheless, ECs expressed a willingness to participate in zoonotic disease training, underscoring the need for further education. Conclusions: This study highlights the critical need for ongoing education for ECs on rodent reservoirs, diseases, and biosafety measures to enhance their safety and reduce the risk of zoonotic infections. The findings offer valuable insights for developing strategies aimed at improving awareness and strengthening biosafety practices within this occupational group. [ABSTRACT FROM AUTHOR]

Background Leptospirosis and rickettsial infections are bacterial zoonoses prevalent in different geographical locations and presents with overlapping symptoms. Objective To identify foetal outcomes in pregnant women diagnosed with rickettsial infections, including scrub typhus and leptospirosis, along with their associated factors. Methods A comprehensive search was conducted in MEDLINE/PubMed, Scopus, CENTRAL (Cochrane), Web of Science, PsycINFO, Academic Search Premier, CINAHL, and Embase using defined search terms. Studies involving pregnant women with diagnosed leptospirosis and rickettsial infections, including scrub typhus, were selected. Two independent reviewers screened titles and abstracts using the Rayyan Web interface. Data extraction was performed in Microsoft Excel, with Zotero for reference management. Study quality was assessed using Joanna Briggs Institute Critical Appraisal tools. Data synthesis included narrative analysis. Results Fifty-four studies were included: 22 on scrub typhus, 14 on rickettsial infection, 16 on leptospirosis, and 2 on all three infections. Of 176 scrub typhus cases, 53 resulted in foetal loss and 3 in neonatal death. Among 38 rickettsial infection cases, 4 had foetal loss. Out of 63 leptospirosis cases, 13 experienced foetal loss. Six maternal deaths occurred due to scrub typhus and one due to Rocky Mountain spotted fever. Conclusion Leptospirosis and rickettsial infections, including scrub typhus, are important causes of pregnancy loss. Further research is needed to better understand and mitigate these risks in pregnant women. [ABSTRACT FROM AUTHOR]

AbstractGraphene quantum dots (GQDs) were used for surface modification of a screen-printed paper electrode (SPPE) for the development of a mobile phone-integrated immunosensor for the detection of scrub typhus. GQDs were synthesized from a 1.8% starch solution via a hydrothermal method and characterized by ultraviolet–visible (UV–Vis) spectroscopy, fluorescence, Fourier transform infrared spectroscopy and dynamic light scattering. Furthermore, anti-56 kDa type specific antigen (TSA) antibodies were used for immobilization on the GQD-modified SPPE working electrode using EDC/NHS (N-ethyl-N′-(3-(dimethylamino)propyl)carbodiimide/N-hydroxysuccinimide) (1:1) chemistry. The TSA antigen was used at different concentrations to interact with specific antibodies, and the response was recorded via cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy using potassium ferricyanide K4[Fe(CN)6]− as a redox indicator. The developed immunosensor showed an excellent sensitivity of 17.40 µA cm−2 ng−1 and a limit of detection of 0.399 ng µL−1. The developed immunohybrid sensor is a novel mobile phone-integrated, highly specific and stable platform for Orientia tsutsugamushi. [ABSTRACT FROM AUTHOR]

Wild rodents and their ectoparasites are known reservoirs for various zoonotic pathogens, highlighting the need for detailed studies into their roles in disease transmission. Our research investigated the spatial distribution of rodents and their ectoparasites to better understand the epidemiology of vector‐borne zoonotic diseases (VBZDs), including severe fever with thrombocytopenia syndrome (SFTS), Lyme disease, Q fever, and scrub typhus. We analyzed samples from 540 rodents and 6785 mites, detecting the presence of Borrelia spp., the causative agent of Lyme disease, in 0.9% of rodents and SFTS virus (SFTSV) in 1.0%. In mites, Borrelia spp. and Orientia tsutsugamushi, the bacteria causing scrub typhus, were detected in 0.3% of samples each. Phylogenetic analysis identified the SFTSV sequence as type B3, the Borrelia spp. sequence as B. afzelii, and the O. tsutsugamushi sequence as Karp‐related. Notably, SFTSV was detected for the first time in mites in South Korea, and B. afzelii was found in mites for the first time globally. These findings emphasize the critical need for continuous analysis of VBZDs to anticipate future trends and develop a comprehensive monitoring system. Further research into the rodent and mite populations in South Korea is essential to fully assess the potential risks of VBZDs. [ABSTRACT FROM AUTHOR]

Background: Scrub typhus is a common rickettsial infection endemic in India and is an important cause of acute febrile illness among children. Clinical manifestations vary from mild-to-severe affecting almost all organ systems with a high fatality rate. To reduce morbidity and mortality, a high index of suspicion, timely diagnosis, and treatment are crucial. However, due to lack of awareness, low index of suspicion among clinicians, and non-specific clinical presentation which overlaps with other tropical endemic infections of India such as dengue, chikungunya, malaria, and leptospirosis, scrub typhus is often underdiagnosed in our country. Aims and Objectives: (1) To find the prevalence of scrub typhus among children presenting with fever for the last 5 days, (2) To study their clinico-demographic profiles. Materials and Methods: Blood collected from children aged 1 month to 12 years of age presenting with fever for the last 5 days were tested for scrub typhus immunoglobulin M enzyme-linked immunosorbent assay. Clinical characteristics and laboratory parameters of the patients were collected. The results obtained were analyzed and interpreted. Results: Out of 865 pediatric patients presenting with fever, only 227 (26.24%) were positive for scrub typhus. Maximum cases (45.37%) were found in the age group >5-12 years. Fever was the presenting feature in all the cases. Other common presentations were hepatosplenomegaly, lymphadenopathy, pain abdomen, rash, and eschar. Conclusion: Although scrub typhus is an easily treatable disease, timely diagnosis and treatment are needed to avoid complications which require a high degree of suspicion among clinicians along with a robust laboratory setup with adequate diagnostic facilities. [ABSTRACT FROM AUTHOR]

Background: The rickettsioses, except for typhus fever and scrub typhus (ST), were not really recognized as distinct clinical entities until the early 20th century. Only when specific rickettsial serologic testing was introduced in the 1940s could the precise etiologies of various rickettsial diseases (RDs) be determined with certainty. Although ST is a well- recognized zoonotic disease entity, but non-scrub typhus rickettsial infection like spotted fever group and typhus group are not well studied in India and are still underestimated. Methods: We report cases who had shown seropositivity of spotted fever and typhus fever RD in IgM and IgG ELISA whose samples were referred from various hospitals of Delhi/National Capital Region in which clinicians had strong suspicion of rickettsiosis other than ST or Weil—Felix test found positive for any of the OX2, 19, and K antigens. Results: We reported 18 cases of SFG and TGRD with mostly cases presented with fever followed by hepato-intestinal symptoms. Conclusion: The vast variability and nonspecific presentation of rickettsiosis in spotted and typhus fever at times have often made it difficult to diagnose clinically. Prompt antibiotic therapy shortens the course of the disease, lowers the risk of complications, and in turn, reduces morbidity and mortality owing to RDs. There is a distinct need for physicians and health care workers at all levels of care in India to be aware of the clinical features, available diagnostic tests and their interpretation, and the therapy for these infections. [ABSTRACT FROM AUTHOR]

Simple Summary: Chiggers are the exclusive vector of scrub typhus. A total of 61 chigger species were identified from Apodemus latronum, which is an endemic mouse species in southwest China. There was an age bias; adult A. latronum had higher infestation indices of chiggers (PM = 38.28%, MA = 5.11) than juvenile mice (PM = 12.63%, MA = 0.97). The mouse hosts with poor nutrition had higher chigger infestation indices than the hosts with good nutrition. The chigger infestation obviously fluctuated along different altitude gradients, and the β diversity of the chigger community showed a gradually increasing tendency from the low to high altitudes. The dominant chigger species had high spillover potentials, dispersing from high to low altitudes. The temperature and humidity are the most important factors influencing the chigger infestation. Chiggers are the exclusive vector of Orientia tsutsugamushi, which is the causative agent of scrub typhus. Based on the field surveys in southwest China between 2001 and 2022, this paper retrospectively reported the chigger infestation and distribution on the large-eared field mouse (Apodemus latronum), an endemic rodent species in the region, for the first time. A total of 933 chiggers were collected from 501 mice, and these chiggers were identified as 2 families, 8 genera, and 61 species. The overall infestation prevalence (PM) and mean abundance (MA) of A. latronum with chiggers reached 19.76% and 1.86 mites/per mouse, respectively. The chigger infestation indices on adult A. latronum (PM = 38.28%, MA = 5.11) were higher than those on juvenile mice (PM = 12.63%, MA = 0.97) with p < 0.01, showing an age bias of infestation. The relative fatness (K) was used to reflect the nutrition status of the mouse host. The mouse hosts with good nutrition (K = 3.4 ± 0.89 g/cm3) harbored fewer chiggers than the hosts with poor nutrition (K = 2.2 ± 0.90 g/cm3) (p < 0.01). The infestation indices of chiggers on A. latronum obviously fluctuated along different altitude gradients (p < 0.01). With the increase in altitudes, the β diversity of the chigger community showed a gradually increasing tendency. The spillover chord diagram, which was based on indices of PAC (potential for apparent competition), revealed high spillover potentials of dominant chigger species dispersing from high altitude gradients to the lowest one. The chigger abundance was positively correlated with the mean monthly temperature (tmp), mean monthly humidity (hum), the mean monthly precipitation (pre), and the human footprint (hfp), and it was negatively correlated with the altitude (ele) (p < 0.05). The temperature and humidity are the most important factors which influence the chigger infestation. [ABSTRACT FROM AUTHOR]

Background: Thromboembolic events are a well-recognized cause of in-hospital deaths of patients with infectious diseases. However, thromboembolic events in patients with scrub typhus, caused by Orientia tsutsugamushi have rarely been reported. This study aimed to assess risk factors associated with thromboembolic events in patients with scrub typhus. Methods: All 93 scrub typhus patients' diagnoses were confirmed serologically or by positive nested polymerase chain reaction (PCR). The clinical and laboratory findings from 12 scrub typhus patients with thromboembolic events and 81 scrub typhus patients with nonthromboembolic events were retrospectively studied. To determine the factors implicated in thromboembolic events, we performed multivariate logistic regression analysis using the six independent factors identified by the univariate analysis. Findings: The mean age of the patients in the thromboembolic group was 76.4 years (median, 76 years), and in nonthromboembolic group it was 64.6 years (median, 65 years) (P<0·001). Thromboembolic events were observed in 12 patients. These events included acute coronary syndrome (n = 5), acute limb ischemia (n = 4), ischemic stroke (n = 1), deep vein thrombosis combined with pulmonary thromboembolism (n = 1), and left common iliac artery aneurysm with a thrombus (n = 1). According to multivariate analysis, the following four factors were significantly associated with the thromboembolic events: 1) treatment with rifampin (OR = 57.6; CI 1.2–2700.3), 2) Taguchi genotype (OR = 41.5, P = 0.028; CI 1.5–1154.6), 3) atrial fibrillation (OR = 9.4, P = 0.034; CI 1.2–74.0), and 4) age (OR = 1.1, P = 0.046; CI 1.0–1.3). Conclusions: Our study suggests that clinicians should be cautious when managing patients with scrub typhus to avoid the development of thromboembolic events, especially in patients with risk factors such as treatment with rifampin, Taguchi genotype, atrial fibrillation, and advanced age. Author summary: Scrub typhus, a disease caused by Orientia tsutsugamushi, is typically treated with antibiotics. It can sometimes lead to serious complications, including thromboembolic events. These events can be life-threatening but have been rarely reported due to under-suspicion in clinical practice, as their rarity often leads to them being overlooked. In this regard, our study suggests that clinicians should be cautious when managing patients with scrub typhus to prevent the development of thromboembolic events, especially in patients with risk factors such as treatment with rifampin, Taguchi genotype, atrial fibrillation, and advanced age. [ABSTRACT FROM AUTHOR]

Rickettsiosis includes a diversity of culture-negative non-specific systemic infections. Laboratory diagnosis of rickettsiosis is often not easy. In this 12-month study, six patients with a variety of rickettsia infections of the spotted fever group, typhus group and scrub typhus were diagnosed directly or indirectly by metagenomic next-generation sequencing (mNGS). The patient with Japanese spotted fever was rapidly made when mNGS analysis of the patient's blood revealed Rickettsia japonica sequences. For the two patients with Rickettsia felis chest infections, the bacterium was detected in the bronchoalveolar lavage of one case and lung biopsy of the other. Both patients had underlying malignancies, carcinoma of the breast and carcinoma of the lung respectively, and were on chemotherapy with immunosuppressive effect. For the remaining three patients who presented over a period of 13 weeks, all had fever, headache and the typical eschar. They also had increased serum transaminases and responded promptly to doxycycline. However, the Weil-Felix test results of all three patients were negative. Since we considered the three cases typical of rickettsiosis, we submitted their serum samples for mNGS analysis. Results showed that Orientia tsutsugamushi sequences were present in the serum of one case. In view of the positive mNGS results, we repeated the Weil-Felix test for the residual sera of all three patients and it revealed that those of the other two cases showed OX-19 titers of 1:640 and 1:160 respectively, inferring that these two patients probably had rickettsiosis of the typhus group. As for the patient positive for O. tsutsugamushi sequences, we also detected IgM for O. tsutsugamushi in the serum, which double confirmed that it was a case of scrub typhus. mNGS is an important molecular tool and can complement serology for laboratory diagnosis of rickettsiosis. Author summary: Rickettsiosis includes a diversity of systemic infections presented with non-specific symptoms. Laboratory diagnosis of rickettsiosis is often not easy. In this 12-month study, six patients with a variety of rickettsia infections were diagnosed directly or indirectly by metagenomic next-generation sequencing (mNGS). These include one patient with Japanese spotted fever in whom Rickettsia japonica sequences were detected in blood, two patients with Rickettsia felis chest infections in whom R. felis sequences were detected in respiratory samples, one patient with scrub typhus in whom Orientia tsutsugamushi sequences were detected in serum, and two patients with rickettsiosis of the typhus group. In particular, the last three patients had initial false-negative Weil-Felix test results performed in a central reference laboratory but the diagnosis of rickettsiosis was subsequently confirmed by mNGS and repeated serology. mNGS is an important diagnostic tool for rickettsiosis and other difficult-to-diagnose systemic infections. [ABSTRACT FROM AUTHOR]

ABSTRACT: Background: Scrub typhus, caused by Orientia tsutsugamushi , is a commonly occurring, but underdiagnosed rickettsial infection in India. Considering the high incidence of scrub typhus among patients with acute febrile illness in the hospital setting and the paucity of community seroprevalence studies, we aimed to estimate the prevalence of scrub typhus in the community in the Bengaluru Rural District. Methods: A pilot cross-sectional survey was conducted between October and December 2022 among eligible asymptomatic adults from five randomly selected villages of the Bangalore Rural District after obtaining written informed consent. Serum immunoglobin M (IgM) and immunoglobin G (IgG) antibodies were tested using the respective enzyme-linked immunosorbent assay (ELISA) kits from InBios International Inc, Seattle, USA. Seroprevalence was defined as positivity to either IgG or IgM antibodies or both. Results: The study reported a seroprevalence of 8.9% (95% CI 4.8%–14.7%) among 146 asymptomatic adults. The IgG and IgM antibodies were positive in 7.5% and 2.1% of participants, respectively. Conclusions: A community seroprevalence of 8.9% warrants further epidemiological surveys and surveillance in the context of climate change, variable clinical presentations of scrub typhus, and the possible need to include this disease in the clinical practice algorithm in the primary care setting. We recommend study designs with "One Health" lens to monitor the trend of this re-emerging public health problem. [ABSTRACT FROM AUTHOR]

ABSTRACT: Introduction: Similar presenting manifestations in early phase and lack of awareness of aetiology of acute febrile illness (AFI) are major challenges in management of AFI. Material and Methods: This was a retrospective observational cross-sectional study conducted in the Department of Microbiology, NRS Medical College, from 1 July 2022 to 30 June 2023 in serologically diagnosed febrile patients attending the outpatient department or admitted. Clinical and epidemiological data and laboratory parameters were recorded in a pretested structured questionnaire study tool, and collected data were analysed on MS-Excel sheets with various charts and tables. Results: A total of 1711 serologically diagnosed febrile patients showed preponderance of dengue (38.3%), followed by leptospirosis (25%), scrub typhus (23.9%), malaria (12.6%), and enteric fever (1.92%). A majority of cases were male, less than 40 years of age, and from the rural population (73.2%), except in malaria (urban = 79.6%). The mean duration of fever was 9 days. Febrile cases were recorded maximum during the monsoon and postmonsoon periods (66.5%). The common manifestations are fever, headache (46.2%), pain abdomen (7.8%), nausea, and vomiting (9.4%). Thrombocytopenia with bleeding manifestation was higher in dengue (18%) cases. Mortality in dengue cases was recorded with multiorgan dysfunction syndrome (MODS). Scrub typhus cases showed seizure (8.3%) and altered sensorium (5%) due to fatal meningoencephalitis. Fatality in leptospirosis was mostly due to acute kidney injury (29.5%) and Weil's disease (4.4%). Conclusion: Misdiagnosis or incorrect diagnosis and delay in initiation of appropriate treatment results in increased morbidity and mortality in AFI. Determination of epidemiological features and clinical manifestations of AFI along with timely correct diagnosis will benefit clinicians in proper treatment initiation, thereby reducing morbidity and mortality. [ABSTRACT FROM AUTHOR]

Background: Scrub typhus, a zoonotic disease, is transmitted to humans by the bite of larval trombiculid mite. Keeping in view the morbidity and mortality associated with undiagnosed cases (due to both lack of specific diagnostic tests and ignorance about the disease), the disease deserves a special mention. Aims and Objectives: The aims and objectives of the study were to assess complications and atypical manifestations of scrub typhus fever in this subpopulation and to assess the prognosis of patients presenting with atypical manifestations/ complications. Materials and Methods: This is a longitudinal observational study on the basis of clinical and laboratory evidence at Department of Pediatrics, Calcutta-National-Medical College and Hospital, Kolkata, West Bengal, from March 2021 to February 2022. Children between >28 days and <12 years with atypical manifestations of scrub typhus who were scrub immunoglobulin (Ig)M positive (Serum and/or cerebrospinal fluid) were included in the study. Results: Of the 120 scrub typhus IgM-positive patients admitted in 1 year, complications present in 35%. These patients developed encephalitis, encephalomyelitis, neurological deficits, myocarditis, disseminated intravascular coagulation, acute kidney injury, atypical pneumonia, acute respiratory distress syndrome, acute encephalitis syndrome (23.8%), myocarditis with/without heart failure (14.3%), and multi-inflammatory syndrome in children with/without severe acute respiratory syndrome coronavirus 2 IgG (14.2%). There is a statistically significant association between the duration of fever at admission and pediatric intensive care unit (PICU) admission, the longer the fever duration at admission, the higher the rate of complications and thus PICU admission. Conclusion: Scrub typhus infection has expanded its various forms, presenting in various atypical manifestations alongside the common clinical features. Multiple cases of multiorgan involvement in the form of multi-inflammatory syndrome and hemophagocytic lymphohistiocytosis have been reported in the background of COVID-19 infection, alongside a significant percentage of scrub typhus infection reported in infancy. Thus, early detection is important to start intervention. [ABSTRACT FROM AUTHOR]

Simple Summary: Chiggers are common ectoparasites on rodents and other small mammals, and they transmit scrub typhus, a zoonotic disease. Dehong in Yunnan Province of southwest China is located on the China–Myanmar border, and it is a focus of scrub typhus. The present paper reports the infestation and distribution of chiggers on small mammals in Dehong for the first time. From 1760 rodents and other sympatric small mammals, a total of 9309 chiggers were identified, representing 117 species. Most chigger species had low host specificity. Leptotrombidium deliense, a major vector of scrub typhus in China, was the dominant chigger species in Dehong, and it was mainly distributed in flatland areas and indoors. The infestation and community indexes of chiggers in mountainous areas and outdoors were higher than those in flatland areas and indoors. The species abundance distribution of the chigger community conformed to log-normal distribution, and the total number of chigger species was roughly estimated to be 147. The species diversity of the chigger community is high in Dehong, with an obvious environmental heterogeneity. The low host specificity of chiggers and the occurrence of a large number of L. deliense in Dehong would increase the transmission risk of scrub typhus on the China–Myanmar border. Chiggers (chigger mites) are a group of tiny arthropods, and they are the exclusive vector of Orientia tsutsugamushi (Ot), the causative agent of scrub typhus (tsutsugamushi disease). Dehong Prefecture in Yunnan Province of southwest China is located on the China–Myanmar border and is an important focus of scrub typhus. Based on the field surveys in Dehong between 2008 and 2022, the present paper reports the infestation and ecological distribution of chiggers on the body surface of rodents and other sympatric small mammals (shrews, tree shrews, etc.) in the region for the first time. The constituent ratio (Cr), prevalence (PM), mean abundance (MA), and mean intensity (MI) were routinely calculated to reflect the infestation of small-mammal hosts with chiggers. Additionally, the species richness (S), Shannon–Wiener diversity index (H), Simpson dominance index (D), and Pielou's evenness index (E) were calculated to illustrate the chigger community structure. Preston's log-normal model was used to fit the theoretical curve of species abundance distribution, and the Chao 1 formula was used to roughly estimate the expected total species. The "corrplot" package in R software (Version 4.3.1) was used to analyze interspecific relationships, and the online drawing software was used to create a chord diagram to visualize the host–chigger associations. From 1760 small-mammal hosts, a total of 9309 chiggers were identified as belonging to 1 family, 16 genera, and 117 species, with high species diversity. The dominant chigger species were Leptotrombidium deliense, Walchia ewingi, and Gahrliepia longipedalis, with a total Cr = 47.65% (4436/9309), among which L. deliense is the most important vector of Ot in China. The overall infestation indexes (PM, MA, and MI) and community parameters (S, H, and E) of chiggers in the mountainous areas and outdoors were higher than those in the flatland areas and indoors, with an obvious environmental heterogeneity. Leptotrombidium deliense was the dominant species in the flatland and indoors, while G. longipedalis was the prevalent species in the mountainous and outdoor areas. The species abundance distribution of the chigger community conformed to log-normal distribution with the theoretical curve equation: S (R) ′ = 28 e − [ 0.23 (R − 0) ] 2 , indicating the existence of many rare species and only a few dominant species in the community. The expected total number of chigger species was roughly estimated to be 147 species, 30 more than the 117 species actually collected, suggesting that some uncommon species may have been missed in the sampling survey. The host–parasite association analysis revealed that one host species can harbor different chigger species, and one chigger species can parasitize different host species with low host specificity. A positive or negative correlation existed among different chigger species, indicating a cooperative or competitive interspecific relationship. The species diversity of chiggers is high in Dehong on the China–Myanmar border, and a large host sample is recommended to find more uncommon species. There is an obvious environmental heterogeneity of the chigger community, with different species diversity and dominant species in different environments. The low host specificity of chiggers and the occurrence of a large number of L. deliense in Dehong, especially in flatland areas and indoors, would increase the risk of persistent transmission of scrub typhus in the region. [ABSTRACT FROM AUTHOR]

Background: In urban Thailand, arboviral infections dominate diagnoses of acute undifferentiated fevers (AUFs) owing to their well-defined epidemiology and characteristic clinical presentations. However, rickettsial diseases, also endemic in this setting, remain under-recognized owing to challenges in early detection. Objective: This study aimed to identify potential rickettsial infections among patients with AUF in Bangkok and vicinity utilizing leftover nucleic acid extracted from serum samples from patients initially suspected of but negative for arbovirus infections. Materials and Methods: A total of 609 nucleic acid samples were screened for rickettsial bacteria using real-time PCR, targeting the 17-kDa common antigen gene of Rickettsia spp. and the 47-kDa gene of Orientia tsutsugamushi. Results: Nine samples were positive for Rickettsia spp. and two were positive for O. tsutsugamushi. DNA sequence and phylogenetic analyses based on partial 17-kDa antigen and citrate synthase (gltA) genes identified the Rickettsia-positive samples as R. typhi in eight cases and R. felis in one case. Analysis of the 56-kDa type-specific antigen gene identified the two O. tsutsugamushi isolates as Gilliam-related genotypes. Although rickettsial diseases typically present with mild symptoms, two patients with R. typhi infection (murine typhus) developed respiratory distress syndrome, highlighting the potential for rare but serious complications. Conclusion: This study underscores the critical importance of differential diagnosis and prompt, effective intervention to prevent complications in suspected cases. [ABSTRACT FROM AUTHOR]

Background:Rickettsia spp. are vector-borne zoonotic pathogens that cause febrile illness in humans. Rickettsioses is not included in the Colombian national surveillance system and is subsequently expected to be underreported. This cross-sectional study aimed to determine the seroprevalence of Rickettsia spp. and the closely related Orientia tsutsugamushi in two indigenous populations residing in the Sierra Nevada de Santa Marta, Colombia. Materials and Methods: Serum samples (n = 539) were collected from the Wiwa and Koguis people between 2021 and 2022. Serum samples were screened for spotted fever group (SFG) and typhus group (TG) Rickettsia spp. using the Fuller laboratories Rickettsia IgG IFA kit and for O. tsutsugamushi with the Scrub Typhus Detect™ IgG ELISA. Results: We observed an overall seroprevalence of 26.2% (95% confidence interval [CI] 22.5–30.1] for Rickettsia spp. of the SFG, 5.4% (95% CI 3.6–7.6) for Rickettsia spp. of the TG and 4.3% (95% CI 2.7–6.3) for O. tsutsugamushi. Common risk factors for zoonotic disease infections were assessed for 147 of the Wiwa participants. Increased odds of seropositivity for SFG Rickettsia spp. were observed for Wiwa participants who cared for livestock, including assisting with the birth of cattle (odds ratio [OR] = 8.85; 95% CI 1.54–50.90; p = 0.015) and goats (OR = 7.60; 95% CI 1.70–33.90; p = 0.008). Conclusions: These results highlight a notable exposure to Rickettsia spp., especially the SFG, in rural Colombia. Together with recent reports of high mortality for Rocky Mountain Spotted Fever in nearby regions of South America, more detailed investigations focusing on improving knowledge and awareness as well as "One Health" and "causes-of-fever" studies are needed. The characterization of Rickettsia spp. infections in humans, livestock, and tick vectors with their potential transmission routes could make a high impact on these easily treatable diseases. [ABSTRACT FROM AUTHOR]

Scrub typhus is caused by the Gram-negative obligate intracellular bacterium Orientia tsutsugamushi, and this tick-borne disease is difficult to distinguish from other acute febrile illnesses as it typically presents with symptoms such as rash, crusting at the bite site, headache, myalgia, lymphadenopathy, and elevated liver transaminases. It can often be diagnosed clinically, but not all patients present with characteristic symptoms, so serological diagnosis and molecular techniques may be required. However, existing diagnostic tests often have low sensitivity and specificity, making early detection difficult. This study presents a nucleic acid extraction method using large volumes of plasma and buffy coat to increase sensitivity, as well as an improved detection method using two target genes. Using the I-PULL device, nucleic acids can be extracted from up to 4 mL of sample in 30 min, avoiding contamination. The extracted DNA detects two genes of O. tsutsugamushi, increasing sensitivity compared to single-gene detection. Clinical validation in 38 patient samples showed 100% specificity and 95.24% sensitivity for the single target gene, with specificity and sensitivity rising to 100% when both genes are analyzed. This molecular diagnostic platform can be useful for distinguishing scrub typhus from similar diseases. [ABSTRACT FROM AUTHOR]

Background Scrub typhus is highly endemic in northern Thailand yet awareness and knowledge are low. We developed a community engagement project to improve awareness in communities at risk of contracting scrub typhus. Methods We conducted a series of engagement sessions with healthcare workers and community health volunteers so they would, in turn, engage with their communities. We evaluated our activities by assessing the increase in scrub typhus knowledge, using a series of Likert-scale items and open-ended questions. Three to 6 months after the sessions, participants were followed up to collect their experiences training community members. Results Of 134 participants who took part in eight sessions, 87.3% were community health volunteers. Disease knowledge increased substantially after the sessions and was well maintained for up to 5 mo. Satisfaction was high and, through participant feedback, engagement materials were improved to be more useful to the communities. People with higher education had higher scores and retention. Conclusions Community engagement was shown to be an effective tool to develop and carry out health-promoting activities in a culturally and context-appropriate manner. [ABSTRACT FROM AUTHOR]

Background: Scrub typhus (ST, also known as tsutsugamushi disease) is a common febrile vector-borne disease in South Korea and commonly known as autumn- and female-dominant disease. Although understanding changes in seasonality and sex differences in ST is essential for preparing health interventions, previous studies have not dealt with variations in periodicity and demographic characteristics in detail. Therefore, we aimed to quantify the temporal dynamics of seasonal patterns and sex differences in the incidence of ST in South Korea. Methods: We extracted epidemiological week (epi-week)-based ST cases from 2003 to 2019 Korean National Health Insurance Service data (ICD-10-CM code: A75.3). To determine changes in seasonality and sex differences, year-, sex-, and age-group-stratified male-to-female ratios and wavelet transform analyses were conducted. Results: Between 2003 and 2019, 213,976 ST cases were identified. The incidence per 100,000 population increased by 408.8% from 9.1 in 2003 to 37.2 in 2012, and subsequently decreased by 59.7% from 2012 to 15.0 in 2019. According to the continuous wavelet transform results, ST exhibited a dual seasonal pattern with dominant seasonality in autumn and smaller seasonality in spring from 2005 to 2019. Overall, the periodicity of seasonality decreased, whereas its strength decreased in autumn and increased in spring. With an overall male-to-female ratio being 0.68:1, the ratio has increased from 0.67:1 in 2003 to 0.78:1 in 2019 (Kendall's τ = 0.706, p < 0.001). However, interestingly, the ratio varied significantly across different age groups. Conclusions: Our findings quantitatively demonstrated changes in seasonality with dual seasonal pattern and shortened overall periodicity and a decrease in sex differences of ST in South Korea. Our study suggests the need for continuous surveillance on populations of vector and host to address ST dynamics to preemptively prepare against global warming. [ABSTRACT FROM AUTHOR]

Scrub typhus is an acute illness caused by the bacteria Orientia tsutsugamushi and is transmitted by mites. Scrub typhus propagates via infected chigger bites (larval stage). Diagnosing scrub typhus is challenging due to its ability to mimic symptoms of other febrile illnesses. Conventional methods such as Weil‐Felix, ELISA, and PCR are available for diagnosing scrub typhus. The Weil‐Felix test was formerly used in developing nations to diagnose scrub typhus, but it is not recommended since it lacks both specificity and sensitivity. IFA and ELISA are superior for detecting scrub typhus; however, they are not as effective at detecting the illness in its early stages and require convalescent sampling to confirm positive samples. However, because the Orientia tsutsugamushi serotypes differ in their genetic makeup, PCR‐based approaches have become less applicable despite their higher specificity and sensitivity. Nanomaterial‐based biosensing could help detect scrub typhus early due to its high surface area, electrical conductance, and chemical stability. This study emphasizes the need for point‐of‐care detection of this under‐diagnosed but fatal disease, emphasizing the importance of nanobiosensors in early diagnosis. The pathophysiology of scrub typhus, standard diagnostic procedures, and the critical role that nanobiosensors play in the early detection of scrub typhus are discussed. [ABSTRACT FROM AUTHOR]

Background: Scrub typhus and dengue, common etiologies of acute encephalitis syndrome, present with similar clinico-laboratory profiles but differ in management protocol. Objective: We aimed to devise a score differentiating between scrub typhus meningoencephalitis (STM) and dengue encephalopathy (DE). Methods: A prospective cohort of 204 children, (aged 6 months to 14 years) presenting with acute encephalitis syndrome in a public teaching hospital in northern India was subjected to standardized workup including serum IgM against Orientia tsutsugamushi and Dengue virus. Clinico-laboratory features were compared between STM and DE using univariate and multivariate analysis. Area under the receiver operating characteristic (ROC) curve (AUROC) for the score derived from independent predictors and its sensitivity, specificity, predictive values was calculated at cutoffs. Results: STM and DE IgM ELISA were positive in 38 (18.6%) and 41 (20.1%) children, respectively. Longer duration of fever, prodromal stage, respiratory complaints and pneumonia were significantly frequent in STM; however, swelling, petechiae and myalgia were significantly prevalent in DE. STM had higher blood total leukocyte count (TLC), higher CSF protein and lower CSF sugar compared to DE. At admission, TLC >10,000/mm3, pneumonia, absence of myalgia and petechiae were independent predictors for differentiating STM from DE. AUROC of novel score (range: −5 to 5) was 0.879 (95% CI: 0.805–0.952). Score at cutoff ≥5 had 100% specificity and 100% PPV for differentiating STM from DE. Conclusions: Prediction score may benefit physicians to differentiate between these two infections and treat them accordingly. [ABSTRACT FROM AUTHOR]

Objective To establish a nomogram model for tsutsugamushi disease complicated with sepsis based on Lasso regression, so as to provide a reference for the diagnosis and treatment of tsutsugamushi disease complicated with sepsis. Methods We selected patients with scrub typhus patients admitted to Kunming Third People’s Hospital from June 2012 to December 2023 as the research subjects (n = 235), with scrub typhus patients patients with sepsis as the experimental group (n = 138) and scrub typhus patients patients without sepsis as the control group (n = 97), Lasso regression was used to screen the influencing factors of scrub typhus combined with sepsis, and a nomogram model was constructed through logistic regression. The effectiveness of the model was evaluated using receiver operating characteristic (ROC) curves and calibration curves, and clinical utility analysis was performed using decision curve analysis (DCA). Results The results of multivariate analysis through logistic regression showed: that age (OR = 1.039, 95%CI: 1.017～1.061), PLT (OR = 0.995, 95%CI: 0.990～1.000), UA (OR = 1.004, 95%CI: 1.001 ～1.008) and IgA (OR = 0.680, 95%CI: 0.472 ～0.979) were independent influencing factors of scrub typhus combined with sepsis. The area under the ROC curve (AUC) was 0.721 (95%CI: 0.656～0.786, P < 0.001), the sensitivity of the model was 69.1%, and the specificity was 63.1%. The calibration curve indicates that the model had good consistency, and the DCA indicated that the model had a high net benefit value. Conclusion Patients with scrub typhus are associated with increased age and UA levels and decreased PLT and IgA levels, and have a higher risk of secondary sepsis. [ABSTRACT FROM AUTHOR]

Acute encephalitis syndrome (AES) is a major public health concern in India as the aetiology remains unknown in the majority of cases with the current testing algorithm. We aimed to study the incidence of Japanese encephalitis (JE) and determine the aetiology of non‐JE AES cases to develop an evidence‐based testing algorithm. Cerebrospinal fluid (CSF) samples were tested for Japanese encephalitis virus by ELISA and polymerase chain reaction (PCR). Multiplex real‐time PCR was done for Dengue, Chikungunya, West Nile, Zika, Enterovirus, Epstein Barr Virus, Herpes Simplex Virus, Adenovirus, Cytomegalovirus, Herpesvirus 6, Parechovirus, Parvovirus B19, Varicella Zoster Virus, Scrub typhus, Rickettsia species, Leptospira, Salmonella species, Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Plasmodium species and by ELISA for Mumps and Measles virus. Of the 3173 CSF samples, 461 (14.5%) were positive for JE. Of the 334 non‐JE AES cases, 66.2% viz. Scrub typhus (25.7%), Mumps (19.5%), Measles (4.2%), Parvovirus B19 (3.9%) Plasmodium (2.7%), HSV 1 and 2 (2.4%), EBV and Streptococcus pneumoniae (2.1% each), Salmonella and HHV 6 (1.2% each) were predominant. Hence, an improved surveillance system and our suggested expanded testing algorithm can improve the diagnosis of potentially treatable infectious agents of AES in India. [ABSTRACT FROM AUTHOR]

Background: Tetracyclines are a class of broad-spectrum antibiotics favored by dermatologists. Over the last decade, the clinical efficacy of tetracyclines has expanded into various dermatoses. Summary: This review tries to encompass the possible indications of tetracycline in the field of dermatology and possible mechanisms of action. This comprehensive review encompasses all possible indications of tetracyclines besides acne vulgaris and rosacea: hidradenitis suppurativa, autoimmune bullous dermatoses, vitiligo, alopecia, prurigo pigmentosa, granulomatous dermatoses, Kaposi's sarcoma, cold urticaria, atopic dermatitis, scrub typhus, scarring, and miscellaneous dermatoses. We also focus on the recently approved sarecycline, a third-generation narrow-spectrum tetracycline, and its clinical efficacy and potential impact on the microbiome. Our review provides a better understanding of this extremely familiar drug class and encourages its use in a wider spectrum of dermatologic diseases and symptoms. Key Messages: This study comprehensively reviewed the current literature on potential indications of tetracyclines in the field of dermatology. Plain Language Summary: Despite their initial approval as antibiotics, the clinical usage of tetracyclines by dermatologists has been expanded to dermatoses with a predominantly inflammatory pathophysiology. The potential indications of tetracyclines in the field of dermatology include not only acne and rosacea but also hidradenitis suppurativa, autoimmune bullous dermatoses, vitiligo, alopecia, prurigo pigmentosa, granulomatous dermatoses, Kaposi's sarcoma, cold urticaria, atopic dermatitis, scrub typhus, scarring, and miscellaneous dermatoses. Sarecycline has shown promising results in rosacea in addition to its approval for acne vulgaris with a narrow antimicrobial spectrum and less impact on the microbiome, indicating possible superiority over other tetracyclines in terms of antibiotic resistance. [ABSTRACT FROM AUTHOR]

Prior to the devastating earthquake in Nepal in 2015, scrub typhus was not recognized as a highly endemic disease in the country. This contrasted with neighboring India, where scrub typhus is endemic and there have been sporadic outbreaks of severe forms. This discrepancy underscores the limitations in our comprehensive understanding of the scrub typhus epidemiological patterns in Nepal, especially before 2015. To better understand the dynamic and current status of scrub typhus, this study investigated its prevalence among patients with acute febrile illness in two hospitals located in Pokhara city, Kaski district and Bharatpur city, Chitwan district during 2009–2010. Our findings revealed that 31.5% (239 of 759 patients) of the cases were positives for scrub typhus based on serological and pathogen detection assays. These results provide crucial insights into the pre-earthquake endemicity of scrub typhus in Nepal, implying its long-standing presence in the region prior to the significant environmental transformations caused by the 2015 earthquake. This study also emphasizes the need for heightened awareness and improved diagnostic capabilities to effectively manage and control scrub typhus, which remains a significant public health concern in Nepal. [ABSTRACT FROM AUTHOR]

Spotted fever group (SFG) rickettsia, the causative agent of SFG rickettsiosis, is predominantly carried by ticks, whereas Orientia tsutusgamushi, the causative agent of scrub typhus, is primarily transmitted by chigger mites in Japan. In this study, we attempted to isolate intracellular eubacteria from Leptotrombidium scutellare, a major vector of O. tsutsugamushi; moreover, we isolated an SFG rickettsia using a mosquito‐derived cell line. Draft genome sequences of this unique isolate, by applying criteria for species delimitation, classified this isolate as a novel strain, proposed as "Rickettsia kedanie." Further genetic analysis identified conserved virulence factors, and the isolate successfully propagated in mammalian cells, suggesting its ability to cause diseases in humans. The presence of SFG rickettsia in unfed larvae implies potential dual‐pathogen carriage and reflects a symbiotic relationship similar to that between the mites and O. tsutsugamushi, indicating possibility of its transovarial transmission from female adults. Furthermore, conserved genomic similarity of the novel isolate to known SFG rickettsia suggests potential multiple hosts, including chiggers and ticks. In the natural environment, ticks, chigger mites, and wild animals may carry new isolates, complicating the infection cycle and increasing the transmission risks to humans. This discovery challenges the conventional association of SFG rickettsia with ticks, emphasizing its implications for research and disease control. However, this study was confined to a particular species of chigger mites and geographic area, underscoring the necessity for additional studies to comprehend the ecological dynamics, host interactions, and health implications linked to this newly identified SFG rickettsia. [ABSTRACT FROM AUTHOR]

Background Globally, India has a high zoonotic disease burden and lacks surveillance data in humans and animals. Rodents are known reservoirs for many zoonotic diseases and their synanthropic behavior poses a great public health threat. Methods In this study, trapped rodents/shrews from randomly selected villages within Puducherry, India, and their ectoparasites were screened for zoonotic pathogens, namely, Orientia tsutsugamushi , other pathogenic rickettsiae, Leptospira spp. Cryptosporidium spp. Coxiella burnetii and methicillin-resistant Staphylococcus aureus (MRSA) using conventional PCR. A total of 58 rodents/shrews were trapped from 11 villages. The species trapped were Suncus murinus (49/58, 84.48%), Rattus rattus (8/58, 13.79%) and Rattus norvegicus (1/58, 1.72%). All ectoparasites collected were identified as mites and its infestation rate was 46.55% (27/58). Results Real-time PCR targeting the 47 kDa gene of O. tsutsugamushi revealed positivity in one rodent and one shrew (3.45%) and two mite pools (7.41%). Conventional PCR targeting the 56 kDa gene revealed positivity in one shrew and two mite pools and the phylogenetic analysis of all three amplicons indicated the circulation of the Gilliam-related serotype. MRSA was detected in the alimentary tract of a shrew (1/32, 3.13%). Leptospira spp. Rickettsia, Cryptosporidium spp. and Co. burnetii tested negative. Conclusions The detection of zoonotic pathogens within reservoir hosts and vectors poses a risk of transmission to humans. This study signifies the need for zoonotic pathogen surveillance in synanthropic rodents/shrews. [ABSTRACT FROM AUTHOR]

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ABSTRACT: Purpose: Scrub typhus is a potentially life-threatening febrile illness associated with serious complications viz. pneumonia, acute respiratory distress syndrome, hepatic failure, acute kidney injury, encephalitis, and shock often culminating in mortality. We aimed to identify the predictors of mortality in scrub typhus. Methods: This prospective observational study was conducted in a tertiary referral hospital of the north Indian state of Uttarakhand on in-patients of scrub typhus hospitalized over 1 year Results: Of the 109 cases studied (54.1% males), 44% were aged <40 years. Fever (95.4%), loss of appetite (55.9%), myalgia (47.7%), pallor (40.3%), hepatomegaly (27.5%), eschar (17.4%), and splenomegaly (13.7%) were the main clinical features. Hepatic transaminitis (69.7%), renal insufficiency (44.0%), respiratory failure (37.6%), shock (33.9%), central nervous system (CNS) involvement (21.1%), and severe anemia (7.3%) were the major complications at presentations. Intensive care and mechanical ventilation were utilized in 33.9% and 15.5% of cases, respectively. Multivariate logistic regression suggested renal insufficiency, CNS involvement, shock, severe anemia, and mechanical ventilation independently associated with death. Conclusion: Respiratory failure, renal insufficiency and neurological involvement, mechanical ventilation, shock, and severe anemia at presentation predict mortality in scrub typhus. [ABSTRACT FROM AUTHOR]

Objectives: Scrub typhus is the most common rickettsial disease in India, caused by Orientia tsutsugamushi and transmitted by chigger mites. Previously prevalent in South India, a resurgence of scrub typhus cases has recently affected Eastern India. This study aimed to estimate the prevalence and describe the clinicolaboratory profile of scrub typhus in paediatric patients (1-12 years old) living in Eastern India. Methods: This prospective observational study was conducted from January to December 2019 at the Dr B C Roy Post Graduate Institute of Paediatric Sciences, Kolkata, India. All acute undifferentiated cases of febrile illness, in patients aged between 1-12 years, were tested using scrub typhus serology by ELISA. Demographic details, clinical features, laboratory findings, complications and treatment outcomes of these scrub typhus patients were extracted and analysed. Results: Out of 1,473 patients with acute febrile illness, 67 (4.5%) children were diagnosed with scrub typhus. The mean age of the selected patients was 5.22 ± 3.05 years, and the majority (64.2%) had been running a fever since the preceding 7-14 days. Gastrointestinal symptoms such as vomiting (43.3%) and abdominal pain (32.8%) were most frequently observed. Major clinical signs of scrub typhus were hepatomegaly (41.8%) and splenomegaly (31.3%). Complications were observed in 74.6% of patients, with thrombocytopenia (40.3%) and meningoencephalitis (29.9%) occurring more frequently. The case fatality rate of the study sample was 1.5%. Conclusion: Classical eschar was absent in three-fourth of the studied patients. Hence, this study advocates laboratory scrub typhus tests for all suspected cases in the endemic region (Eastern India). Prompt treatment with doxycycline and/or azithromycin could prevent complications such as thrombocytopenia/meningoencephalitis and reduce mortality. [ABSTRACT FROM AUTHOR]

ObjectiveTo investigate the clinical characteristics and epidemiological history of an imported case of tsutsugamushi disease, and to identify the diagnosis and key points of prevention and control.MethodsThe clinical symptoms, diagnosis and treatment process, and epidemiological data were retrospectively analyzed for a case of tsutsugamushi disease in Changning District. A risk assessment was conducted concurrently.ResultsThe patient had a history of traveling to or living in Xishuangbanna, Yunnan Province, and presented with symptoms such as recurrent high fever, scabbing and peanut-sized lymph node swelling behind the ear, and red rashes on the face and trunk. The patient tested positive for nucleic acid from Orientia tsutsugamushi and was cured after receiving comprehensive treatment. The patient resides in Shanghai, where the likelihood of hosts and vectors being present in winter is low, hence the risk of epidemic transmission was deemed low.ConclusionThe clinical manifestations of tsutsugamushi disease are not typical in the early stages of the disease. Attention should be paid to epidemiological history and specific symptoms of tsutsugamushi disease, and to strengthen health education and promotion efforts for key populations.

Background: Scrub typhus, caused by Orientia tsutsugamushi, rarely leads to central nervous system involvement. Although intracerebral bleeding is rare due to endemicity and a significant proportion of underdiagnoses, it should be considered a noteworthy differential diagnosis in endemic regions in patients with relevant history and clinical findings. Case presentation: We present the case of a 40-year-old Nepali woman who visited the emergency department with complaints of left-sided weakness for 6 hours and an acute febrile illness with an eschar for 7 days and was diagnosed with scrub typhus by immunoglobulin M enzyme-linked immunosorbent assay of the serum. Imaging revealed a right-sided frontotemporal hematoma, and further examination revealed pulmonary edema with multiple organ dysfunction syndrome. The patient was mechanically ventilated and was treated with antibiotics, steroids, vasopressors, and antipyretics. However, the hematoma was treated conservatively, with ongoing neurological recovery at the 6-month follow-up. Conclusion: Although neurological complications and intracranial hemorrhage are uncommon, physicians must be cautious when making differential diagnoses and initiating appropriate therapies to avoid serious or fatal complications. [ABSTRACT FROM AUTHOR]

Figure depicts the sequential approach used for in-silico vaccine design and development and immune response prediction. [Display omitted] Scrub typhus, a potentially life-threatening infectious disease, is attributed to bacteria Orientia tsutsugamushi (O. tsutsugamushi). The transmission of this illness to humans occurs through the bite of infected chiggers, which are the larval forms of mites belonging to the genus Leptotrombidium. In this research, we developed a subunit vaccine specifically designed to target outer membrane proteins. Immunodominant cytotoxic T-lymphocytes (CTLs), B- lymphocytes (BCLs), and major histocompatibility complex (MHC)- II epitopes were identified using machine learning and bioinformatics approaches. These epitopes were arranged in different combinations with the help of suitable linkers like AAY, KK, GPGPG and adjuvant (cholera toxin B) that resulted in a vaccine construct. Physiochemical properties were assessed, where the predicted solubility (0.571) was higher than threshold value. Tertiary structure was predicted using I-TASSER web server and evaluated using Ramachandran plot (94 % residues in most favourable region) and z-score (−6.04), which had shown the structure to have good stability and residue arrangement. Molecular docking with immune receptors, Toll-like receptor (TLR)-2 and -4 showed good residue interaction with 13 and 5 hydrogen bonds respectively. Molecular dynamics simulations of receptor-ligand complex provided the idea about the strong interaction having 1.524751 × 10-5 eigenvalue. Amino acid sequence of vaccine was converted to nucleotide sequence and underwent codon optimization. The optimized codon sequence was used for in-silico cloning, which provided idea about the possibility of synthesis of vaccine using E. coli as host. Overall, this study provided a promising blueprint for a scrub typhus vaccine, although experimental validation is needed for confirmation. Furthermore, it is crucial to acknowledge that while bioinformatics provides valuable insights, in-vitro and in-vivo studies are imperative for a comprehensive evaluation of vaccine candidate. Thus, the integration of computational predictions with empirical research is essential to validate the efficacy, safety, and real-world applicability of the designed vaccine against Scrub Typhus. Nevertheless, the findings are good to carry forward for in-vitro and in-vivo investigations. [ABSTRACT FROM AUTHOR]

Background: In this observational study, clinical characteristics, etiologies, and outcomes of patients admitted to the hospital with community-acquired acute kidney injury (CAAKI) have been compared in contrast to those who hospital-acquired Acute Kidney Injury (HAAKI). Methods: This was a prospective study of adults aged 18 years or above diagnosed with acute kidney injury (AKI) over a period of 17 months at a tertiary care hospital. Results: 230 patients had AKI with the mean age of the study population being 45.33 ± 12.68 years. 178 (77.4%) patients were enrolled from medical unit, 25 (10.7%) from surgical unit, and 27 (11.7%) from obstetrical unit. The observed incidence of AKI was 15/1000 admissions. About 58.2% had CAAKI and 96 (43.7%) had HAAKI. Out of 230 patients, 170 (73.9%) patients were male and 60 (26.1%) were female. Sepsis was the most common (52.1%) etiology of AKI among the medical cases. Urosepsis, scrub typhus, and pneumonia were the most common causes of AKI. Sixty percent of AKI was Kidney Disease Improving Global Outcomes Stage 1 or 2 and 40% was in Stage 3. Oliguria was seen in 56.5%, hyperkalemia in 34.7%, fluid overload in 6.1%, and metabolic acidosis in 22.6%. The majority of patients had multiple organ involvement (52.1%) at the time of enrollment. About 116 (50.4%) had lung injury requiring mechanical ventilation and 95 (41.3%) were on inotropes. Mortality occurred in 19.5%. Anemia, the use of vasopressor drugs, and the need for intensive care support were independent predictive factors for mortality. Conclusion: AKI was common in hospitalized patients and leads to significant inhospital mortality. AKI is largely a CAAKI, and the lesser extent is due to HAAKI. Many causes are potentially preventable. Early fluid resuscitation, effective antibiotics, appropriate antidotes, and timely referral of established AKI patients to centers with dialysis facilities can improve AKI outcomes. [ABSTRACT FROM AUTHOR]

Introduction: Scrub typhus or bush typhus or chigger - borne typhus is a leading cause of undifferentiated febrile illness caused by the intracellular gram negative bacteria orientia tsutsugamushi of family rickettsiaceae which was first isolated and identified in 1930 in japan. Bacteria orientia tsutsugamushi of family rickettsiaceae which was first isolated and identified in 1930 in japan. Humans are infected when they are bitten by the mite larvae(chiggers). The available serological methods for diagnosis of scrub typhus were weil felix test, ifa and elisa .in this study we used elisa for detection of igm antibodies, which has a good sensitivity and specitivity. Aim: To determine the seroprevalence of scrub typhus among febrile patients attending to tertiary care hospital using igm elisa. Materials and Methods: This study is prospective observational study was conducted since june 2023 to november 2023(6months period), at tertiary care hospital guntur. total 366 samples were tested for scrub typhus by igm elisa. these samples also testedfor other diseases like malaria, dengue fever, enteric fever, leptospiroses and other fevers which are common cause of fever prevalent in this area. Results - out of 366 samples 41 were detected igm antibodies by elisa, in that, males were 22(53.65%) and females were 19(46.34%). age group mostly involved were below 20 years . Conclusion: Scrub typhus should include in common cause of febrile illness along with other causes which are prevalent in this area, and test for detection and diagnosis of scrub typhus should include in the panel of diagnostic tests for febrile illness. [ABSTRACT FROM AUTHOR]

Background: Fever associated with thrombocytopenia is a common clinical issue in pediatric wards. Literature shows very minimal data on fever associated with thrombocytopenia in children, even though there are some studies on profile of individual diseases like dengue fever, typhoid fever, malaria in children. Aim & Objective: This study was conducted to analyze clinico-etiological profile in preference to infective etiology and outcome of children with febrile thrombocytopenia. This was a prospective observational study conducted in Pediatric Dept, Government Medical College, Anantapur from January 2021 to June 2022. 150 children in the age group of one month to twelve years of age who fulfilled the criteria of fever for 5 days or more with thrombocytopenia were taken into the study and children with known ITP and hematological malignancy, Pseudo thrombocytopenia were excluded. After informed written consent detailed history, clinical examination and necessary laboratory investigation were undertaken. Study parameters were documented in Excel spread sheet and analyzed using SPSS version 16 software. Results: This study demonstrated no gender difference. Analysis of different age group revealed two third study group comprised of children more than 5 years. Comparison of different age group and gender was done which showed in infants, toddlers and preschool children, males were more affected and in school going children females were more affected. Geographic and Seasonal analysis revealed more than 50% children from Anantapur, Hindupur, Kalyandurg and 62% of the children were residing in Rural areas. 85% of study group presented between months of August and November. Clinical features and Physiological status at admission were analyzed for frequency and occurrence in different age groups which revealed altered sensorium, GI bleeds, seizures and oliguria were common in infants. Hepatomegaly was seen in two third children, facial puffiness in half, pallor in one-third. Shock was seen in 26% of children. Shock was frequent in infants. Positive Tourniquet testing was seen in 21% children. Thrombocytopenia was graded as per WHO guidelines, of which 46% hadsevere and 43% had moderate thrombocytopenia. Severe type of thrombocytopenia was the common type associated with bleeding manifestations. Among bleeding manifestations GI bleeds was the commonest followed by petechiae and other bleeds, bleeding manifestations were common among infants, school going children. Bleeding manifestations were common in ALL followed by Dengue fever. Univariate analysis of clinical signs and lab parameters among the bleeding manifestations group and non- bleeding manifestations group was undertaken. Mortality in febrile thrombocytopenia is 3.3%. This was due to Multi-Organ Dysfunction Syndrome. Blood product transfusion was given in 8 patients of which 2 required Platelet Transfusion due to severe Thrombocytopenia, 3 required FFP Transfusion due to Coagulopathy, 3 required Fresh Whole Blood due to Falling Hematocrit. Conclusion: The analysis revealed significant association between bleeding manifestation and positive tourniquet test and low platelet count. Early rise in platelet count (< 3 days) was seen in nonbleeding group compared to bleeding group. In this study Dengue Fever was the commonest etiology followed by Undifferentiated fever, Malaria, Scrub typhus and Enteric Fever. [ABSTRACT FROM AUTHOR]

This study evaluated the use of F-18 fluorodeoxyglucose (FDG) PET/CT imaging to differentiate between scrub typhus and systemic lupus erythematosus (SLE) in patients presenting with lymphadenopathy. We carried out a retrospective analysis of 18 scrub typhus patients and seven SLE patients, using various imaging parameters, including lymph node size, spleen and liver lengths, the distance between the two farthest lesions (Dmax), and assessments of glucose metabolism. On FDG PET images, we measured the maximum standardized uptake value (SUVmax) of the lymph nodes, spleen, and liver and the mean standardized uptake value (SUVmean) of the liver and spleen. The Dmax values of scrub typhus patients were significantly longer than those of SLE patients, indicating that lymphadenopathy is more generalized in the patients with scrub typhus. The SUVmax values for the lymph node, spleen, and liver were also higher in patients with scrub typhus, while the SUVmean of the liver and spleen did not differ between the two groups. This study is the first to compare FDG PET/CT images between these two conditions, suggesting the potential of this imaging modality to provide critical diagnostic distinctions. [ABSTRACT FROM AUTHOR]

Simple Summary: Leptotrombidium imphalum (a chigger species) can serve as a transmitting vector of scrub typhus. Based on the field investigation in southwest China from 2001 to 2022, this article presents the first report on the distribution and infestation of L. imphalum on small mammals in the region. A total of 2161 L. imphalum were identified from 218 small mammal hosts that crossed three orders, and the majority of the mites were found on the order Rodentia (rodents). Different host species had different susceptibility to the infestation of L. imphalum, and the shrew gymnure (Neotetracus sinensis) was much more susceptible to the infestation than other host species. Leptotrombidium imphalum exhibited an aggregated distribution among different individuals of its hosts. The positive correlation between the infestation indices for L. imphalum on small mammals and the occurrence of scrub typhus, together with the low host specificity of the mite, indicates the potential risk of the mite. Leptotrombidium imphalum is a species of chigger mites, and it can serve as a transmitting vector of scrub typhus. Southwest China is an important focus of scrub typhus. Based on the field investigation in southwest China from 2001 to 2022, this article presents the first report on the distribution and infestation of L. imphalum on rodents and other sympatric small mammals in the region. A total of 2161 L. imphalum were identified from 218 small mammal hosts in 21 of 114 survey sites. The 17 host species of L. imphalum crossed 13 genera and 5 families in 3 orders (Rodentia, Eulipotyphla, and Scandentia), indicating the low host specificity of the mite. The Asian house rat (Rattus tanezumi) was the dominant host species in the 21 sites where L. imphalum were collected, and 49.38% of mites were found on R. tanezumi. Different small mammals had different susceptibility to the infestation of L. imphalum. The prevalence (PM = 27.66%), infestation mean abundance (MA = 6 mites/per examined host), and mean intensity (MI = 21.69 mites/per infested host) for L. imphalum on the shrew gymnure (Neotetracus sinensis) were much higher than those on other host species (p < 0.05), indicating N. sinensis had a high susceptibility to the infestation of L. imphalum. The infestation indices for L. imphalum on small mammal hosts varied along different altitude and latitude gradients (p < 0.05), indicating the environmental heterogeneity of the mite infestation. Leptotrombidium imphalum exhibited an aggregated distribution among different individuals of its hosts. Besides the low host specificity of L. imphalum, the prevalence of the mite was positively correlated with the occurrence of scrub typhus, indicating the potential risk of the mite. [ABSTRACT FROM AUTHOR]

Background: Acute undifferentiated fever (AUF) remains a significant reason for hospitalization among children, particularly in Southeast Asia. Common causative agents include dengue, scrub typhus, murine typhus, leptospirosis, and enteric fever. This study aims to delineate the clinical and etiological profiles of AUF in children. Materials and Methods: A prospective observational study was conducted over one year in the Department of Pediatrics at a tertiary care hospital in Central India. The study enrolled children with fever lasting less than 21 days and without a specific focus of infection identified through history, physical examination, and routine investigations. Results: Among the 90 children included in the study, the most prevalent cause of undifferentiated fever was typhoid fever (31.1%), followed by malaria (21.1%), dengue fever (18.9%), and urinary tract infections (10%). Other notable causes included acute gastroenteritis (8.9%), pneumonia (5.6%), bronchiolitis (2.2%), hepatitis (1.1%), and pharyngotonsillitis (1.1%). Common clinical symptoms observed were pyrexia (100%), headache (65.6%), rash (47.8%), and abdominal pain (31.1%). Laboratory findings indicated mild anemia in the majority of cases, leukopenia in cases of dengue and malaria, and thrombocytopenia in dengue cases. Conclusion: Non-malarial infections are predominant causes of AUF in children within this region of Central India. Scrub typhus, dengue, and enteric fever were identified as significant contributors. The study underscores the necessity for improved diagnostic facilities to reduce the proportion of undiagnosed fevers, often assumed to be viral in nature. [ABSTRACT FROM AUTHOR]