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This study analyzed HGA and SFTS in patients with suspected tick-borne infection by focusing on key differences that clinicians can easily recognize. A retrospective analysis was performed on confirmed patients with HGA or SFTS in 21 Korean hospitals from 2013 to 2020. A scoring system was developed by multivariate regression analysis and accuracy assessment of clinically easily discriminable parameters was performed. The multivariate logistic regression analysis revealed that sex (especially male sex) (odds ratio [OR] 11.45, P = 0.012), neutropenia (< 1500) (OR 41.64, P < 0.001), prolonged activated partial thromboplastin time (OR 80.133, P < 0.001), and normal C-reactive protein concentration (≤ 1.0 mg/dL; OR 166.855, P = 0.001) were significantly associated with SFTS but not with HGA. Each factor, such as meaningful variables, was given 1 point, and a receiver-operating characteristic curve with a cutoff value (> 1) in a 5-point scoring system (0–4 points) was analyzed to evaluate the accuracy of differentiation between HGA and SFTS. The system showed 94.5% sensitivity, 92.6% specificity, and an area under the receiver-operating characteristic curve of 0.971 (0.949–0.9). Where HGA and SFTS are endemic, the scoring system based on these four parameters such as sex, neutrophil count, activated partial thromboplastin time, and C-reactive protein concentration will facilitate the differential diagnosis of HGA and SFTS in the emergency room in patients with suspected tick-borne infectious diseases. [ABSTRACT FROM AUTHOR]

Severe fever with thrombocytopenia syndrome (SFTS) is a zoonotic tick-borne infectious disease caused by the SFTS virus (SFTSV). Few studies have assessed SFTS seroprevalence among veterinary hospital staff and their awareness of SFTS. From January to May 2021, serum samples from 103 veterinary hospital staff were tested for SFTS using an enzyme-linked immunosorbent assay (ELISA), an immunofluorescence assay, and a 50% plaque reduction neutralization antibody test, which yielded positive results in four (3.9%), three (2.9%), and two (1.9%) participants, respectively. A questionnaire was used for an epidemiological investigation. ELISA positivity was higher among those who lacked awareness of possible animal-to-human SFTS transmission (p = 0.029). SFTS awareness was significantly lower among veterinary hospital staff than among the veterinarians (p < 0.001). Providing staff with training concerning standard precautions and the use of appropriate personal protective equipment is important. [ABSTRACT FROM AUTHOR]

We designed a highly sensitive reverse transcription nested polymerase chain reaction targeting the M-segment (NPCR-M) of severe fever with thrombocytopenia syndrome (SFTS) virus. NPCR-M was performed in parallel with three other referenced PCR assays QPCR-S, PCR-M, and NPCR-S to assess their clinical usefulness as routine diagnostic techniques for SFTS. In this multi-centered prospective study, 122 blood samples from 38 laboratory-confirmed SFTS patients and 85 control samples were used. The results demonstrated that QPCR-S and NPCR-S had better sensitivity rate up to 21 days after symptom onset however, the PCR-M showed poor sensitivity after 7 days of symptom onset. Our designed NPCR-M had a higher detection rate up to 40 days from symptom onset and revealed the persistence of SFTSV RNA in the early convalescent phase. No false-positive results were seen for the control samples. Additionally, NPCR-M showed positive results for a sample that initially showed negative results from other PCRs and for many other samples collected in the convalescent phase of SFTS. Our designed nested PCR is suitable for SFTSV detection in patients' blood collected in the acute and early convalescent phase of SFTS, and shows better sensitivity and high specificity even up to 40 days after symptom onset. [ABSTRACT FROM AUTHOR]

Background: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease. SFTS is caused by the SFTS virus, a novel phlebovirus, and is spread by ticks. Methods: A 50-year-old man was admitted to our hospital with the chief complaint of fever and was diagnosed with confirmed SFTS. An epidemiological investigation was conducted, and immunofluorescent antibody assays (IFAs) were performed to determine the role of the patient's three dogs in the transmission. PCR assays were performed using ticks that were collected with the dragging and flagging method from the patient's dogs and home. Results: PCR results were positive, and IFA confirmed an increased antibody titer. Although the reverse transcription PCR results of the three dogs were negative for SFTS virus, one dog had an elevated SFTS IFA immunoglobulin G (IgG) titer of 1:1,024. Moreover, a number of ticks were observed in the area surrounding the dog cages. Based on the findings of the patient interview, the patient was likely to have acquired SFTS by blood splash because he removed or burst ticks from the dogs with his bare hands. Although no tick bites were reported, tick transmission could not be ruled out. Studies have shown that only one in three individuals with a diagnosis of SFTS recalls a tick bite; thus, a definite exclusion of tick transmission in this case was not possible. Conclusions: The epidemiological findings of our case suggest a possible relationship between tick infestation in domestic dogs and SFTS virus transmission to humans. However, there is no direct evidence supporting this viral transmission route. Future studies are needed to further investigate a potential route of SFTS transmission by exposure to engorged tick blood or pet dogs. [ABSTRACT FROM AUTHOR]

Background Doxycycline is currently the most frequently used treatment in patients with scrub typhus. However, doxycycline-resistant strains have been found, necessitating the development of a new treatment. Rifampin is known to be effective even for such strains. Our aim in this study was to compare the effects of rifampin and doxycycline treatment in patients with scrub typhus in areas in which resistance to doxycycline has not been reported. Methods Patients admitted to Chosun University Hospital and regional network hospitals between 2007 and 2009 with a body temperature ≥37.5°C and suspected to have scrub typhus were randomly assigned to 1 of 2 treatment groups: a group administered doxycycline 100 mg twice daily for 5 days and a group administered rifampin 600 mg once daily for 5 days. For treatment outcomes, fever, headache, muscle ache, and rash clearance times were compared between the groups. Results The rifampin and doxycycline groups showed equivalence in all treatment outcomes evaluated. The proportions of patients with fever clearance within 48 hours were similar between groups. Furthermore, there was no significant difference in the occurrence of side effects following drug administration between groups. Conclusions On the basis of the finding that equivalent treatment effects and safety were found in patient groups that received 600 mg of rifampin and 200 mg of doxycycline, respectively, for 5 days to treat scrub typhus, rifampin may be considered an alternative treatment to doxycycline. Clinical Trials Registration NCT00568711. [ABSTRACT FROM AUTHOR]

We investigated 1,228 residents of 3 rural areas in South Korea and determined that 50 (4.1%) were positive for severe fever with thrombocytopenia syndrome virus antibodies. Fever and gastrointestinal symptoms in the previous 3 years and career duration were associated with virus seropositivity. [ABSTRACT FROM AUTHOR]

Background: Human granulocytic anaplasmosis (HGA) is a tick-borne infectious disease caused by Anaplasma phagocytophilum. To date, there have been no reported cases of A. phagocytophilum infection found in both the biting tick and the patient following a tick bite.Case Presentation: An 81-year-old woman presented with fever following a tick bite, with the tick still intact on her body. The patient was diagnosed with HGA. The tick was identified as Ixodes nipponensis by morphological and molecular biological detection methods targeting the 16S rRNA gene. The patient's blood was cultured after inoculation into the human promyelocytic leukemia cell line HL-60. A. phagocytophilum growth was confirmed via culture and isolation. A. phagocytophilum was identified in both the tick and the patient's blood by Anaplasma-specific groEL- and ankA-based nested polymerase chain reaction followed by sequencing. Moreover, a four-fold elevation in antibodies was observed in the patient's blood.Conclusion: We report a case of a patient diagnosed with HGA following admission for fever due to a tick bite. A. phagocytophilum was identified in both the tick and the patient, and A. phagocytophilum was successfully cultured. The present study suggests the need to investigate the possible incrimination of I. nipponensis as a vector for HGA in Korea. [ABSTRACT FROM AUTHOR]

Background: Human granulocytic anaplasmosis is a tick-borne zoonotic disease caused by Anaplasma phagocytophilum, an obligate intracellular granulocytotropic bacterium.Case Presentation: A 70-year-old female patient was admitted with the clinical signs of fever and an altered state of consciousness 1 week after experiencing a tick bite while planting lawn grass. Magnetic resonance imaging, performed at the time of admission, indicated cerebral infarction in the left basal ganglia, whereas increasing immunofluorescence assay antibody titers for A. phagocytophilum were also documented. A. phagocytophilum was identified using groEL and ankA targeted polymerase chain reaction and sequencing. Because of severe thrombocytopenia, only doxycycline was administered, without any antiplatelet agents. Subsequently, the symptoms improved without any focal neurologic sequela.Conclusion: This is the first reported case of cerebral infarction occurrence in an anaplasmosis patient. [ABSTRACT FROM AUTHOR]