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The aim of this systematic review was to identify articles on prevalence of leptospirosis in stray and sheltered dogs worldwide and access the methodological quality of the recovered papers. Six databases (CABI, Cochrane, Pubmed, Scielo, Scopus and Web of Science) were searched, without restriction on year or location where the studies were performed. The search recovered 476 articles and 60 were selected for analysis according to quality criteria. None of the selected articles showed a complete explanation for the sample size adopted (probabilistic sampling), leading to the impossibility of recalculation of leptospirosis prevalence for stray or sheltered dogs. Among the analyzed papers 43.33% (26/60) showed five of the ten quality criteria analyzed, 16.67% (10/60) three, 15.00% (9/60) four, 10.00% (6/60) six, 6.67% (4/60) eight, only 5.00% (3/60) showed nine of the ten criteria analyzed, whereas two papers showed two [1.67% (1/60)] and seven [1.67% (1/60)] of the ten criteria assessed. The majority of the papers were published in the Americas [45.00% (27/60)] and in the last sixteen years (2003 to 2019) [81.67% (49/60)], and most of the sampled dogs were stray dogs [65.00% (39/60)]. The leptospirosis diagnostic test used more frequently was Micro Agglutination Test (MAT) [78.33% (47/60)] followed by polymerase Chain Reaction (PCR) [23.33% (14/60)], whereas the most common serovars identified were Canicola [71.43% (35/49)], Icterohaemohrragiae [65.31% (32/49)], Grippotyphosa [40.82% (20/49)] and Pomona [40.82% (20/49)]. In conclusion, our results showed that Leptospira spp. is present in stray and sheltered dogs worldwide, but the complete comprehension of the prevalence of leptospirosis in these populations could not be achieved due to the low methodologic quality of the recovered studies about leptospirosis in stray and sheltered dogs.

Objectives. To characterize statewide seroprevalence and point prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Rhode Island. Methods. We conducted a cross-sectional survey of randomly selected households across Rhode Island in May 2020. Antibody-based and polymerase chain reaction (PCR)–based tests for SARS-CoV-2 were offered. Hispanics/Latinos and African Americans/Blacks were oversampled to ensure adequate representation. Seroprevalence estimations accounted for test sensitivity and specificity and were compared according to age, race/ethnicity, gender, housing environment, and transportation mode. Results. Overall, 1043 individuals from 554 households were tested (1032 antibody tests, 988 PCR tests). The estimated seroprevalence of SARS-CoV-2 antibodies was 2.1% (95% credible interval [CI] = 0.6, 4.1). Seroprevalence was 7.5% (95% CI = 1.3, 17.5) among Hispanics/Latinos, 3.8% (95% CI = 0.0, 15.0) among African Americans/Blacks, and 0.8% (95% CI = 0.0, 2.4) among non-Hispanic Whites. Overall PCR-based prevalence was 1.5% (95% CI = 0.5, 3.1). Conclusions. Rhode Island had low seroprevalence relative to other settings, but seroprevalence was substantially higher among African Americans/Blacks and Hispanics/Latinos. Rhode Island sits along the highly populated northeast corridor, making our findings broadly relevant to this region of the country. Continued monitoring via population-based sampling is needed to quantify these impacts going forward.

Several Zika virus (ZIKV) seroprevalence studies have been conducted in Africa, Asia, Oceania, the Americas, and the Caribbean. However, studies on ZIKV seroprevalence are limited in Malaysia though several studies have shown that the disease is endemic in the Malaysian state of Sabah. To evaluate the seroprevalence of ZIKV infection, 818 serum samples were collected from febrile patients and healthy blood donors from the Kudat and Kota Kinabalu districts in Sabah from 2017 to 2018. They were screened for ZIKV infection by IgM and IgG ELISA, and positive ZIKV IgM samples were subjected to a 90% neutralization test for confirmation. Twenty-four (6% [95% CI 4 to 8]) confirmed and two (0.5% [95% CI 0.13 to 1.8]) probable ZIKV infections were detected among 400 febrile illness patients. Of 418 healthy blood donor samples, six (1.4% [95% CI 0.65 to 3]) were determined as confirmed ZIKV infections and six (1.4% [95% CI 0.65 to 3]) indicated probable ZIKV infection. This is the first study on the seroprevalence of ZIKV infections among patients and healthy blood donors in Sabah. Compared with previous studies in Malaysia, this study shows that the incidence of ZIKV infection has increased. It also suggests that a sero-surveillance system is essential to determine the circulation of ZIKV in Sabah, Malaysia.

Background Meningococcal serogroup C (MenC) vaccination was introduced for 14-month-olds in the Netherlands in 2002, alongside a mass campaign for 1–18 year-olds. Due to an outbreak of serogroup W disease, MenC vaccination was replaced for MenACWY vaccination in 2018, next to introduction of a booster at 14 years of age and a catch-up campaign for 14–18 year-olds. We assessed meningococcal ACWY antibodies across the Dutch population in 2016/17 and 2020. Methods In a nationwide cross-sectional serosurvey in 2016/17, sera from participants aged 0–89 years (n = 6886) were tested for MenACWY-polysaccharide-specific (PS) serum IgG concentrations, and functional MenACWY antibody titers were determined in subsets. Moreover, longitudinal samples collected in 2020 (n = 1782) were measured for MenACWY-PS serum IgG concentrations. Results MenC antibody levels were low, except in recently vaccinated 14–23 month-olds and individuals who were vaccinated as teenagers in 2002, with seroprevalence of 59% and 20–46%, respectively. Meningococcal AWY antibody levels were overall low both in 2016/17 and in 2020. Naturally-acquired MenW immunity was limited in 2020 despite the recent serogroup W outbreak. Conclusions This study demonstrates waning of MenC immunity 15 years after a mass campaign in the Netherlands. Furthermore, it highlights the lack of meningococcal AWY immunity across the population and underlines the importance of the recently introduced MenACWY (booster) vaccination.

Background Improved understanding of Bartonella spp. serology in dogs may aid clinical decision making. Objective Describe demographic and geographic patterns of Bartonella spp. seroreactivity in dogs, and describe hematologic and serum biochemical abnormalities in Bartonella spp. seroreactive and nonseroreactive dogs. Animals Serum samples from 5957 dogs in the United States, previously submitted to IDEXX Reference Laboratories. Methods Serum was tested using 3 indirect ELISAs for B. henselae, B. vinsonii subsp. berkhoffii, and B. koehlerae. Complete blood count and serum biochemistry panel results were reviewed retrospectively. Results Overall, 6.1% of dogs were Bartonella spp. seroreactive. Toy breeds were less likely to be seroreactive (3.9%) than mixed breeds (7.5%; adjusted odds ratio [aOR], 0.48; 95% confidence interval [CI], 0.32‐0.72), and dogs

Background Seroprevalence studies of coronavirus disease 2019 (COVID-19) cases, including asymptomatic and past infections, are important to estimate the scale of the disease outbreak and to establish quarantine measures. We evaluated the clinical performance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody assays available in Korea for use in seroprevalence studies. Methods The sensitivity, specificity, cross-reactivity, and interference of five SARS-CoV-2 antibody assays were evaluated using the following: 398 serum samples from confirmed COVID-19 patients, 510 negative control samples from before 2018 (pre-pandemic), 163 serum samples from patients with SARS, Middle East respiratory syndrome (MERS), and other viral infections, and five samples for the interference study. Results The sensitivities of the five assays ranged from 92.2% to 98%, and their specificities, including cross-reactivity and interference, ranged from 97.5% to 100%. The agreement rates were excellent (kappa >0.9). Adjustment of the cutoff values could be considered through ROC curve analysis. The positive predictive values of the individual assays varied from 3.5% to 100% at a 0.1% prevalence but were as high as ≥95% when two assays were combined. Conclusions The prevalence of COVID-19 in Korea is considered to be exceptionally low at present; thus, we recommend using a combination of two or more SARS-CoV-2 antibody assays rather than a single assay. These results could help select SARS-CoV-2 antibody assays for COVID-19 seroprevalence studies in Korea.

Purpose Amidst the on-going SARS-CoV-2 pandemic, healthcare workers have been at a greater risk of disease exposure as they are working in environments chiefly involved in the COVID-19 patient care since March 2020. SARS-CoV-2 antibody testing can prove to be a valuable tool for better understanding of prevalence of disease exposure in this population. Therefore, we conducted this study to grasp the sero-prevalence of COVID-19 antibodies in our hospital to better comprehend the duration of IgG response. Materials & methods This was a longitudinal study involving 305 healthcare workers at Rajiv Gandhi Super Speciality Hospital spanning over a period of four months starting from October 2020 to January 2021. Serum samples were obtained from the study group taken as Day 0 of the study and were screened for the presence of SARS-CoV-2 IgG antibodies using semi-quantitive enzyme linked immunoassay technology from ERBAlisa (India). The Antibody Index was determined. Those showing reactive in the screening test were further followed up on a monthly basis till January 2021 for serial antibody testing. Result The overall seroprevalence for IgG response among the workers was found to be 21.96%. Seropositivity rate was observed to be significantly higher in those having a history of RT-PCR confirmed COVID-19 infection (45.09%) CONCLUSION: Our study demonstrated that healthcare workers have a higher sero-prevalence. Our study also demonstrated that the antibodies developed following COVID-19 infection had a waning effect of protective response following infection.

Background/Aims: Data on the immunoprotective status against measles, mumps, rubella, varicella zoster virus (VZV), hepatitis A virus (HAV), and Epstein-Barr virus (EBV) infection in patients with inflammatory bowel disease (IBD) are still lacking. Therefore, we investigated the seropositivity rates for viral infectious diseases and the associated factors in Korean patients with IBD.Methods: In this retrospective cohort study, serum immunoglobulin G antibody positivity rates against measles virus, mumps virus, rubella virus, VZV, HAV, and EBV viral capsid antigen (VCA) were measured in patients with Crohn’s disease or ulcerative colitis (UC) who first visited the IBD clinic. Seropositivity rates and their associated factors were analyzed.Results: Between January 2016 and December 2018, 263 patients were enrolled (male, 167 [67.3%]; UC, 134 [50.9%]). The median age at serological test was 30 years (interquartile range, 22 to 46). The seropositivity rates were 84.0%, 85.2%, 66.5%, 87.4%, 50.0%, and 93.7% for measles, mumps, rubella, VZV, HAV, and EBV, respectively. Younger age at serological test was associated with seronegative status for measles (adjusted odds ratio [aOR], 0.92; 95% confidence interval [CI], 0.88 to 0.96), VZV (aOR, 0.83; 95% CI, 0.74 to 0.93), and HAV (aOR, 0.93; 95% CI, 0.91 to 0.95). Furthermore, IBD type-UC was associated with seronegative status against VZV (aOR, 0.33; 95% CI, 0.11 to 0.99).Conclusions: Seropositivity rates for common viral infectious diseases in Korean patients with IBD were similar to those of the general population. In the younger age group, protective immunity against measles, VZV, and HAV is required, with proper vaccination, as necessary.

The poultry sector in Pakistan is contributing mainly in bridging gap between demand and supply for protein. Mycoplasma gallisepticum is an emerging bacterium causing serious problems in poultry industry of Pakistan. A cross-sectional study was conducted to evaluate the M. gallisepticum load in poultry populated regions of Pakistan. Total 600 serum and 600 swab samples were collected, 200 from each broiler, layers and breeders poultry in Rawalpindi and Abbottabad districts. Serum samples were analyzed through ELISA for seroprevalence. Swabs were cultured on Frey’s medium followed by PCR and partial mgc2 gene sequencing. Results of seroprevalence of M. gallisepticum showed that layers (75%, n=150) are more positive as compared to breeders (70%, n=140) and broilers (50%, n=100). Typical colonies of the M. gallisepticum were observed in breeder (26.5%), followed by layer (21%) and broilers (9%). A total of 37.1% (n=42) samples were identified positive through PCR out of total 113 cultured based positive samples. A total of six M. gallisepticum isolates of current study showed 98-99 percent similarity with previously reported isolates on the basis of mgc2 gene partial sequencing. The M. gallisepticum was found highly prevalent in different poultry breads. Results of this study would add into basic data and provide a direction for livestock sector to strengthen a control strategy for mycoplasmosis in poultry farms. Resumo O setor avícola do Paquistão está contribuindo principalmente para preencher a lacuna entre a demanda e a oferta de proteína. Mycoplasma gallisepticum é uma bactéria emergente que causa sérios problemas na indústria avícola do Paquistão. Um estudo transversal foi conduzido para avaliar a carga de M. gallisepticum em regiões de avicultura do Paquistão. Um total de 600 amostras de soro e 600 amostras de esfregaço foi coletado, 200 de cada frango de corte, poedeiras e aves reprodutoras nos distritos de Rawalpindi e Abbottabad. Amostras de soro foram analisadas por ELISA para soroprevalência. As zaragatoas foram cultivadas em meio Frey, seguido de PCR e sequenciação parcial do gene mgc2. Os resultados da soroprevalência de M. gallisepticum mostraram que as poedeiras (75%, n = 150) são mais positivas em comparação com matrizes (70%, n = 140) e frangos de corte (50%, n = 100). Colônias típicas de M. gallisepticum foram observadas em reprodutoras (26,5%), seguidas de poedeiras (21%) e frangos de corte (9%). Um total de 37,1% (n = 42) das amostras foi identificado como positivas por PCR de um total de 113 amostras positivas baseadas em cultura. Um total de seis isolados de M. gallisepticum do estudo atual mostrou 98-99% de similaridade com isolados relatados anteriormente com base no sequenciamento parcial do gene mgc2. O M. gallisepticum foi encontrado com alta prevalência em diferentes pães de aves. Os resultados deste estudo acrescentariam dados básicos e forneceriam orientação para o setor pecuário fortalecer uma estratégia de controle da micoplasmose em granjas avícolas.

Pseudorabies (PR), the causative agent of Aujeszky's disease, has rapidly increased in recent years and has caused significant economic losses. To understand the seroprevalence and epidemiological characteristics of PR in Tianjin, China, a total of 23,627 blood and 1,093 tissue samples were collected from 228 pig farms during January 2010 to December 2018. The Pseudorabies virus (PRV) glycoprotein E (gE) antibody was tested by enzyme-linked immunosorbent assay (ELISA), and wild-type PRV (WT PRV) was detected by gE-polymerase chain reaction (PCR). Macroscopic and microscopic lesions were observed in tissue samples. The results showed that 46.70% of the serum samples and 49.76% of pig farms were seropositive for PRV gE antibody based on the ELISA results, and 13.54% of the tissue samples were positive for WT PRV detected by PCR. The positive rate of serum samples increased rapidly after 2011 and reached 62.40% in 2013. Although it gradually decreased from 2014 to 2018, the positive rate of serum samples remained at a high level. The positive rate of pig farms showed the same trend. Moreover, after 2011, the detection rate of WT PRV was increased rapidly and was significantly higher than in 2010 and 2011. Macroscopic and microscopic lesions were observed in various tissues during histopathological examination. Based on univariate analysis, the increased risk of seropositivity was associated with the immune status and infection in sows and fattening pigs. These findings demonstrate that PR was prevalent in the region of Tianjin, China. These epidemiological data can assist in the control of PR.

The COVID-19 pandemic caused by the coronavirus SARS-CoV-2 is continuing to spread globally. SARS-CoV-2 infections of feline and canine species have also been reported. However, it is not entirely clear to what extent natural SARS-CoV-2 infection of pet dogs and cats is in households. We have developed enzyme-linked immunosorbent assays (ELISAs) using recombinant SARS-CoV-2 nucleocapsid (N) protein and the receptor-binding-domain (RBD) of the spike protein, and the SARS-CoV-2 spike-pseudotyped vesicular stomatitis virus (VSV)-based neutralization assay to screen serum samples of 239 pet cats and 510 pet dogs in Minnesota in the early phase of the COVID-19 pandemic from mid-April to early June 2020 for evidence of SARS-CoV-2 exposures. A cutoff value was used to identify the seropositive samples in each experiment. The average seroprevalence of N- and RBD-specific antibodies in pet cats were 8% and 3%, respectively. Among nineteen (19) N-seropositive cat sera, fifteen (15) exhibited neutralizing activity and seven (7) were also RBD-seropositive. The N-based ELISA is also specific and does not cross react with antigens of common feline coronaviruses. In contrast, SARS-CoV-2 antibodies were detected at a very low percentage in pet dogs (~ 1%) and were limited to IgG antibodies against SARS-CoV-2 N protein with no neutralizing activities. Our results demonstrate that SARS-CoV-2 seropositive rates are higher in pet cats than in pet dogs in MN early in the pandemic and that SARS-CoV-2 N-specific IgG antibodies can detect SARS-CoV-2 infections in companion animals with higher levels of specificity and sensitivity than RBD-specific IgG antibodies in ELISA-based assays.

Anthrax is a disease of concern in many mammals, including humans. Management primarily consists of prevention through vaccination and tracking clinical-level observations because environmental isolation is laborious and bacterial distribution across large geographic areas difficult to confirm. Feral swine (Sus scrofa) are an invasive species with an extensive range in the southern United States that rarely succumbs to anthrax. We present evidence that feral swine might serve as biosentinels based on comparative seroprevalence in swine from historically defined anthrax-endemic and non–anthrax-endemic regions of Texas. Overall seropositivity was 43.7% (n = 478), and logistic regression revealed county endemicity status, age-class, sex, latitude, and longitude were informative for predicting antibody status. However, of these covariates, only latitude was statistically significant (β = –0.153, p = 0.047). These results suggests anthrax exposure in swine, when paired with continuous location data, could serve as a proxy for bacterial presence in specific areas.

Although coxsackievirus A21 (CV-A21) has been associated with acute respiratory infection (ARI) as well as poliomyelitis-like paralysis, reports of CV-A21 detection have been quite limited both globally and in Japan. CV-A21 strains were isolated from five sporadic pediatric cases with ARI in 2019 in Yamagata, Japan. Neutralizing antibodies (NT Abs) were then measured against CV-A21 using sera collected in 1976, 1985, 1999, 2009, and 2019 in Yamagata, to clarify the longitudinal epidemiology of CV-A21. The total Ab-positive rate in each year was 15.2% (35/233), 10.7% (30/281), 14.3% (28/196), 3.1% (7/236), and 1.3% (3/226), respectively. Ab-positive rates generally increased with age, especially between 1976 and 1999. Among the total Ab-positive cases, the Ab titers were relatively low; 50 cases belonged to the 1:8-1:16, 40 to 1:32-1:64, 12 to 1:128-1:256 and 1 to 1:1024< groups, respectively. No Ab-positive cases under the age of 10 were observed in any of the years analyzed. In conclusion, this study and previous works suggested that CV-A21 is a unique enterovirus, which is not transmitted readily among young children but causes sporadic ARI cases mainly among those ≥ 15 years of age in the community. This article is protected by copyright. All rights reserved.

Zoonotic orthopoxvirus outbreaks have occurred repeatedly worldwide, including monkeypox in Africa and the United States, cowpox in Europe, camelpox in the Middle East and India, buffalopox in India, vaccinia in South America, and novel emerging orthopoxvirus infections in the United States, Europe, Asia, and South America. Waning smallpox immunity may increase the potential for animal-to-human transmission followed by further community transmission person-to-person (as demonstrated by monkeypox and buffalopox outbreaks) and by contact with fomites (as demonstrated by camelpox, cowpox, and, possibly, Alaskapox). The objectives of this review are to describe the disease ecology, epidemiology, clinical manifestations, prevention, and control of human infections with animal orthopoxviruses and to discuss the association with diminished population herd immunity formerly induced by vaccinia vaccination against smallpox. Internet search engines were queried with key words, and case reports, case series, seroprevalence studies, and epidemiologic investigations were found for review.

A study was carried out in Kamuli and Hoima districts in Eastern and Western regions of Uganda to determine the Taenia solium porcine cysticercosis (PCC) and gastrointestinal (GI) parasites co-infection status in pigs. One hundred sixty-one households were selected randomly and visited between November and December 2019. A household questionnaire was administered, and faecal and blood samples were collected from at least one pig older than 3 months per household. A blood sample was obtained from a jugular venipuncture, and a rectal faecal sample was obtained. Taenia spp. circulating antigen levels in the sample sera were tested using a commercial enzyme-linked immunosorbent assay kit, apDia™ cysticercosis Ag ELISA. The modified McMaster technique was used to identify and quantify the GI parasites. The apparent animal-level seroprevalence for PCC was 4.8% (95% CI 2.7–7.1) and differed across the two districts (p = 0.018). At the pig herd level, the prevalence was 9.7% (95% CI 5.5–14.4). The prevalence of the different nematode eggs and coccidian oocysts in the two districts was as follows: strongyles 79.0% (95% CI 74.3–83.6), coccidia 73.3% (95% CI 68.3–78.6), Trichuris spp. 7.4% (95% CI 4.9–10.6), Strongyloides ransomi 2.1 (95% CI 0.7–3.5) and Ascaris spp. 4.9 (95% CI 2.8–7.4). Overall, across the two districts, the arithmetic mean for the oocysts per gram (OPG) for coccidia was 2042.2 ± 5776.1, and eggs per gram (EPG) were the highest in strongyles 616.1 ± 991. Overall, 57.4% of the porcine cysticercosis seropositive pigs were also positive for at least one of the gastrointestinal helminths which included strongyles, Strongyloides ransomi, Trichuris spp. and Ascaris spp. The co-infection status of pigs with both PCC and GI parasites demonstrated by this study can provide an incentive for integrating the control and management of both parasites with oxfendazole. Further studies are required to understand the feasibility of using oxfendazole including cost–benefit analysis and the acceptability by local stakeholders for the control of T. solium cysticercosis and gastrointestinal parasites in pigs.

BACKGROUND Italy experienced SARS-CoV-2 spread during the second wave and the southern regions were severely affected. In this prospective study, we assessed the changes in SARS-CoV-2 seroprevalence rates in non-vaccinated blood donors to evaluate the spread of SARS-CoV-2 among healthy individuals in our geographical area. METHODS 8,183 healthy blood donors visiting the Transfusion Centre at the University Hospital "Riuniti" of Foggia (Italy) to donate blood from May 2020 to March 2021 were tested twice for anti-SARS-CoV-2 antibodies by Ortho Clinical Diagnostics VITROS® 3600 through anti-SARS-CoV-2 Total and IgG reagent kit. None of the subjects had diagnosed symptomatic COVID-19 infection, and none had received vaccination. RESULTS Overall, 516 out of 8,183 had antibodies to SARS-CoV-2 (total and IgG antibodies) (6.3%, 95% CI: 0.03-0.15%), 387 were male and 129 female. There was a significant increase of seropositive donors from May 2020 to March 2021 (p

Vertebrate surveillance for eastern equine encephalitis virus (EEEV) activity usually focuses on three types of vertebrates: horses, passerine birds, and sentinel chicken flocks. However, there is a variety of wild vertebrates that are exposed to EEEV infections and can be used to track EEEV activity. In 2009, we initiated a pilot study in northern New England, United States, to evaluate the effectiveness of using wild cervids (free-ranging white-tailed deer and moose) as spatial sentinels for EEEV activity. In Maine, New Hampshire, and Vermont during 2009–2017, we collected blood samples from hunter-harvested cervids at tagging stations and obtained harvest location information from hunters. U.S. Centers for Disease Control and Prevention processed the samples for EEEV antibodies using plaque reduction neutralization tests (PRNTs). We detected EEEV antibodies in 6 to 17% of cervid samples in the different states and mapped cervid EEEV seropositivity in northern New England. EEEV antibody-positive cervids were the first detections of EEEV activity in the state of Vermont, in northern Maine, and northern New Hampshire. Our key result was the detection of the antibodies in areas far outside the extent of documented wild bird, mosquito, human case, or veterinary case reports of EEEV activity in Maine, New Hampshire, and Vermont. These findings showed that cervid (deer and moose) serosurveys can be used to characterize the geographic extent of EEEV activity, especially in areas with low EEEV activity or with little or no EEEV surveillance. Cervid EEEV serosurveys can be a useful tool for mapping EEEV activity in areas of North America in addition to northern New England.

Bovine vaccinia (BV) is an infectious disease caused by Vaccinia virus (VACV) characterized by vesicular and exanthematic lesions, mainly in cattle. Although BV has been described in some Brazilian regions in the last decades, official information regarding the current prevalence in bovine herds of Midwestern Brazil is lacking. Thus, the current study aimed to estimate the seroprevalence and risk factors associated with BV in cattle in the Distrito Federal (DF), Brazil. Sera of 312 cows of 64 herds were tested by virus-neutralizing test for VACV antibodies. Herd and animal seroprevalence were estimated to be 33.3% (CI 95%: 18.2–48.3%) and 10.6% (CI 95%: 1.0–20.2%), respectively. Seropositive cows were detected in dairy, beef, and mixed-purpose farms. The results of an epidemiological questionnaire showed that no risk factor analyzed was positively associated with seropositivity to VACV. There was no significant association between type of milking (manual/mechanic) and seropositivity to VACV; however, most seropositive cows were present in farms with high daily milk production and high number of lactating and adult cows. Our results indicate that VACV circulates in many regions of DF with considerable prevalence in dairy cows. Control measures to restrict VACV circulation and consequences of the infection may be advisable.

Background Refugees in Malaysia, who are afflicted by poverty, conflict and poor health, are vulnerable to a range of zoonotic infections in the deprived environmental and social conditions under which they live. Exposure to infections such as leptospirosis, for which rodents are primary hosts, is of particular concern. Methods A wellness program was conducted to determine the presence of antibodies against Leptospira (seroprevalence) in 11 refugee community schools and centers in the Klang Valley, Malaysia. A total of 433 samples were assessed for IgG and IgM antibodies against Leptospira, using enzyme-linked immunosorbent assays (ELISA). Results Overall Leptospira seroprevalence was 24.7%, with 3.0% being seropositive for anti-Leptospira IgG and 21.7% for anti-Leptospira IgM. Factors significantly associated with overall Leptospira seroprevalence included: age, ethnicity, pet ownership, knowledge of disease and awareness of disease fatality. For IgM seroprevalence, significant risk factors included sex, ethnicity, eating habits with hands, pet ownership, the presence of rats, walking in bare feet and water recreation visits. Conclusions These findings highlight the need for improvements in health and well-being among the refugee community through disease awareness programs and provision of healthy behavior programs, particularly in hygiene and sanitation through community engagement activities.

Objective To perform a meta-analysis that investigates the prevalence and seroprevalence of celiac disease (CD) in Chinese general population and high-risk populations, and to summarize data from a serological survey of high-risk populations in Guangdong, China. Methods We collected data from the serological survey of high-risk populations in Guangdong, China (n = 1390) by testing serum tissue transglutaminase immunoglobulin A (tTG-IgA), deamidated gliadin peptides immunoglobulin A (DGP-IgA) and deamidated gliadin peptides immunoglobulin G (DGP-IgG), and also searched Medline, PubMed, Embase, Cochrane and 3 Chinese databases up to December 20, 2020 to estimate the pooled prevalence and seroprevalence of CD in China. Results In the serological survey, 0.94% (13/1390) individuals were positive for CD antibodies. In a meta-analysis of 18 studies, the seroprevalence of CD in Chinese general population was 0.27% (95% CI, 0.02-0.71). The seroprevalence of CD in Chinese high-risk populations was 8.34% (95% CI, 4.90-12.54), significantly higher than that in general population (OR 7.27, 95% CI, 4.06-13.04). The prevalence of biopsied-proven CD in high-risk Chinese populations was 4.44% (95% CI, 1.53-8.58). The seroprevalence of CD was varying with geographic origin, higher in Northern China than that in Southern China. Conclusions The basis for diagnosis of CD in Chinese patients should be through early case-finding by serological screening in high-risk groups; generous serological testing in patients with vague symptoms, especially in Northern Chinese.

Introduction: The effect of SARS-CoV-2 infection in patients with multiple sclerosis (MS) and the influence of disease-modifying therapies (DMT) for MS on COVID-19 are unknown. To date, patients with MS have not been shown to present greater risk of COVID-19 or more severe progression of the disease. Methods: We performed a descriptive study of patients with MS presenting SARS-CoV-2 infection diagnosed with PCR. We analysed demographic, clinical, laboratory, and treatment variables in our sample. Presence of antibodies against the virus was also determined. Results: Relapsing-remitting MS (RRMS) was the most frequent form of MS in our sample. Prognosis was unfavourable in 10.2% of patients, and was associated with older age and higher scores on the Expanded Disability Status Scale (EDSS). Seroprevalence of antibodies against SARS-CoV-2 was 83.3% in our sample. Development of antibodies was not associated with DMT, lymphocytopaenia, or any of the other variables analysed. Conclusions: The incidence of COVID-19 was slightly higher in our sample than in the general population in our province. Unfavourable prognosis was associated with older age and higher EDSS scores. DMT and lymphocytopaenia did not influence the clinical course of COVID-19. Seroprevalence of antibodies against the virus in our sample was similar to that reported for the general population with positive PCR results for the virus; the influence of specific DMTs could not be determined. Resumen: Introducción: El efecto de la infección por SARS-CoV-2 en los pacientes con esclerosis múltiple (EM) y la influencia de los tratamientos modificadores de la enfermedad (TME) es desconocida. Hasta el momento no se ha observado que los pacientes con EM tengan mayor riesgo de infección por COVID-19 ni peor curso evolutivo de la misma. Métodos: Estudio descriptivo de pacientes con EM e infección por SARS-CoV-2 diagnosticada mediante PCR. Hemos analizado variables demográficas, clínicas, de laboratorio y de tratamiento en nuestra muestra. Se ha determinado la presencia de anticuerpos frente SARS-CoV-2 en estos pacientes. Resultados: La forma de esclerosis múltiple remitente recurrente (EMRR) fue la más frecuente en los pacientes con EM e infección por COVID-19. El 10.2% presentó una evolución desfavorable, relacionada con una mayor edad y una EDSS más elevada. La seroprevalencia de anticuerpos frente a SARS-CoV-2 en nuestro estudio ha sido del 83,3%. El desarrollo de anticuerpos no está relacionado con el TME, la presencia de linfopenia u otros factores analizados. Conclusiones: La incidencia de COVID-19 ha sido ligeramente superior a la de la población general de nuestra provincia. La evolución desfavorable se ha relacionado con una mayor edad y una puntuación elevada en la EDSS. El TME y la linfopenia no se han relacionado con el curso de la infección por COVID-19. La seroprevalencia es similar a la encontrada en población general con PCR positiva, sin poder determinar la influencia de los distintos TME.

While evidence suggests presence of HEV infection in humans in Zambia, currently, there is no information on its occurrence in domestic pigs. Here, we investigated the presence of HEV antibodies and genome in domestic pigs in Zambia. Sera (n = 484) from domestic pigs were screened for antibodies against HEV by ELISA while genome detection in fecal (n = 25) and liver (n = 100) samples from slaughter pigs was conducted using nested RT–PCR assay. Overall, seroprevalence was 47.7% (231/484) while zoonotic genotype 3 HEV RNA was detected in 16.0% (20/125) of slaughtered pigs. This is the first report to highlight occurrence of HEV infection in domestic pigs in Zambia. This finding suggests possible contamination of the pork supply chain. Moreover, there is a potential risk of zoonotic transmission of HEV to abattoir workers, pig farmers and handlers.

Background: The Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) is the cause of the Coronavirus Diseases of 2019 (COVID-19). This virus has been responsible for the global pandemic of 2020 and 2021 with over 107 million confirmed cases and over 2.3 million deaths. An important population that deserves meticulous consideration during the COVID-19 pandemic is pregnant woman; however, in many places in the world there is inadequate screening for SARS-COV-2 during pregnancy. We aimed to determine the impact of maternal and neonatal cord blood SARS-COV-2 antibodies and placental transfer ratios in a region with a low screening plan. Methods: We performed a blind study in Babahoyo, Ecuador; one of the SARS-CoV-2epicenters in South America. Blood samples were collected from 100 serum samples collected from pregnant women at the time of delivery along with corresponding neonatal cord blood. SARS-CoV-2 IgG specific antibodies were determined using a enzyme linked immunosorbent assay (ELISA) for IgG and IgM SARS-CoV-2-specific nucleocapsid and spike antigens (DiaPro, Milano, Italy Cat number COV19G.CE). Findings: We observed 32% of pregnant women to be serological positive in areas lacking an appropriate screening program. We also show data that suggests an efficient passive immunization of the fetus to SARS-CoV-2 during pregnancy. Interpretation: There is a high incidence of SARS-CoV-2 infection during pregnancy. The best prevention for protecting the mother from infection is vaccination, which, will provide the fetus and neonate with a strong protection against SARS-CoV-2 infection through passive placental transfer of SARS-CoV-2 specific antibodies. This is especially important because newborns are highly susceptible to many viral infections. Funding: NIAID 1R01AI145829-01 Declaration of Interest: None to declare. Ethical Approval: This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guidelines. This was retrospective study done with samples sent for tests evaluation that were originally not related to this study. A consent waiver was approved since the samples were not collected for the study and the samples used were defined as dischargeable material.

In September 2020, we tested 13,398 persons in Portugal for antibodies against severe acute respiratory syndrome coronavirus 2 by using a quota sample stratified by age and population density. We found a seroprevalence of 2.2%, 3–4 times larger than the official number of cases at the end of the first wave of the pandemic.

Objective Real-time reverse transcription-polymerase chain reaction is the gold standard for the diagnosis of COVID-19, but it is necessary to utilize other tests to determine the burden of the disease and the spread of the outbreak such as IgG-, IgM-, and IgA-based antibody detection using enzyme-linked immunosorbent assay (ELISA). Materials and Methods We developed an indirect ELISA assay to quantitatively measure the amount of COVID-19 IgG, IgM, and IgA antibodies present in patient serum, dried blood, and plasma. Results The population cutoff values for positivity were determined by receiver operating characteristic curves to be 1.23 U/mL, 23.09 U/mL, and 6.36 U/mL for IgG, IgM, and IgA, respectively. After albumin subtraction, the specificity remained >98% and the sensitivity was 95.72%, 83.47%, and 82.60%, respectively, for IgG, IgM, and IgA antibodies to the combined spike subunit 1 receptor binding domain and N proteins in serum. Plasma and dried blood spot specimens were also validated on this assay. Conclusion This assay may be used for determining the seroprevalence of SARS-CoV-2 in a population exposed to the virus or in vaccinated individuals.

Background. This study was conducted to evaluate the anti‐SARS‐CoV‐2 IgM and IgG antibodies among healthcare workers in Guilan. Methods. This cross-sectional study was conducted on 503 healthcare workers. Between April and May 2020, blood samples were collected from the healthcare workers of Razi Hospital in Rasht, Guilan, Iran. Enzyme-linked immunosorbent assay (ELISA) was used for the detection and quantitation of anti‐SARS‐CoV‐2 IgM/IgG antibodies by using kits made by Pishtaz Teb Company, Tehran, Iran. Results. From a total of 503 participants, the result of the anti‐SARS‐CoV‐2 IgM antibody test was positive in 28 subjects (5.6%) and the anti‐SARS‐CoV‐2 IgG antibody test was positive in171 subjects (34%). Participants in the age group of 35–54 years were significantly more likely to have a positive anti‐SARS‐CoV‐2 antibody test than the age group of 20–34 years (odds ratio = 1.53, 95% CI: 1.04–2.25, P = 0.029 ). Also, physicians were significantly more likely to have a positive antibody test than office workers (odds ratio = 1.92, 95% CI: 1.04–3.54, P = 0.037 ). The wide range of symptoms was significantly associated with the positive anti‐SARS‐CoV‐2 antibody test. The most significant association was observed between fever and a positive anti‐SARS‐CoV‐2 antibody test (odds ratio = 3.03, 95% CI: 2.06–4.44, P < 0.001 ). Conclusion. The results of the current study indicated that the seroprevalence of COVID-19 was high among healthcare workers of Guilan Province. It seems that this finding was due to the earlier exposure to COVID-19 and the lack of awareness and preparedness to deal with the pandemic in Iran, compared to other countries.

Purpose To assess the IgG seroprevalence of Toxoplasma gondii as an indicator of past exposure and immunity against infection among children with Down syndrome (DS) in Sana’a city, Yemen. This preliminary study is justified by the primary immunodeficiency of children with DS and the opportunistic nature of the parasite, considering the vague situation of anti-Toxoplasma IgG seroprevalence among children with DS because of neglecting its study on local and global scales. Methods This descriptive, facility-based, cross-sectional study was conducted among 107 children with DS hosted in six randomly selected rehabilitation centers for children with special needs in Sana’a city. Demographics of children and their mothers’ knowledge of toxoplasmosis were collected using a pre-designed, structured questionnaire. Anti-Toxoplasma IgG antibodies were measured in the sera of children using electrochemiluminescence assay. Results Of 107 children with DS, 3 (2.8%) were seropositive for anti-Toxoplasma IgG. Approximately two-thirds (71/106) of the mothers of children with DS were aware of toxoplasmosis. Of whom, 83.1% (59/71) were aware of its congenital complications. Conclusion The majority of children with DS in Sana’a city are seronegative for anti-Toxoplasma IgG, where the seropositivity rate is lower than 3.0%. Therefore, children with DS are non-immune and susceptible to the acquisition of primary infections during their life. Further analytical studies are recommended to determine whether the defective immune response of children with DS is associated with false seronegativity, to assess the role of their mothers’ knowledge in reducing their exposure to infection if they were confirmed truly seronegative and to identify the predictors of infection among them.

The epidemiology of HDV infection worldwide is obscure. Mapping the epidemiology of the infection is highly required, so, we aimed to estimate the prevalence of hepatitis D virus infection among chronic hepatitis B patients and the epidemiological characteristics in the Nile delta in Egypt. This was a prospective observational cross-sectional study including consecutive chronic hepatitis B patients in the out-patient clinics at the Egyptian Liver Research Institute and Hospital (ELRIAH) and its satellites in the Nile Delta from January 2016 until August 2018. They were recruited from patients enrolled in Educate, Test and Treat program, which was implemented in 73 Egyptian Villages. Subjects were tested by using HBsAg serological rapid diagnostic tests (RDTs), and then HBV DNA by PCR was done in HBsAg-positive cases. HDV IgG antibody testing and confirmatory HDV RNA PCR were done. Complete liver functions, abdominal ultrasonography and FibroScan were also performed. The prevalence of HDV was 3.4% using anti-delta antibody (22/631), and only 8 were positive for HDV RNA (8/22, 36.4%). Overall HDV prevalence using PCR was 8/631(1.27%). HDV-positive cases were mainly males (68.2%). Eight cases were cirrhotic (36.4%), 3 (13.6%) had HCC and 7 (31.8%) were HBeAg positive. HDV prevalence is low among chronic hepatitis B patients in the Nile delta, Egypt. Screening for HDV IgG is recommended in CHB patients who had cirrhosis, HCC or HBeAg positive.

A cross-sectional study was carried out to determine the seroprevalence and risk factors of Q fever in sheep in the northern part of Kaduna State, Nigeria. This study aimed to determine Coxiella burnetii infection and its risk factors in sheep in Kaduna State. A total of 400 blood samples consisting of 259 samples from females and 141 from males were aseptically collected from the jugular vein of sheep from flocks in Kaduna State. The sera obtained were screened for Q fever using an indirect enzyme-linked immunosorbent assay (iELISA). The obtained data were analysed to determine whether there is a relationship between sex, age, and the animals tested. The analysis revealed that 8.0% of the sera was seropositive by iELISA. There was no significant difference in Q fever seropositivity in the study area according to the sex of sheep (P > 0.05). There was a statistically significant difference (P < 0.05) in Q fever seropositivity according to the age of sheep. This study indicated a high seroprevalence of Q fever mainly among female animals and older sheep. Further studies are required to determine the epizootiology of Q fever in the study area more precisely.

Background Emergency Departments (EDs) have served as critical surveillance sites for infectious diseases. We sought to determine the prevalence and temporal trends of acute (by PCR) and convalescent (by antibody [Ab]) SARS-CoV-2 infection during the earliest phase of the pandemic among patients in an urban ED in Baltimore City. Methods We tested remnant blood samples from 3255 unique ED patients, collected between March 16th and May 31st 2020 for SARS-CoV-2 Ab. PCR for acute SARS-CoV-2 infection from nasopharyngeal swabs was obtained on any patients based on clinical suspicion. Hospital records were abstracted and factors associated with SARS-CoV-2 infection were assessed. Results Of 3255 ED patients, 8.2% (95%CI: 7.3%, 9.2%) individuals had evidence of SARS-CoV-2 infection; 155 PCR+, 78 Ab+, and 35 who were both PCR+ and Ab+. Prevalence of disease increased throughout the study period, ranging from 3.2% (95%CI: 1.8%, 5.2%) PCR+ and 0.6% (95%CI: 0.1%, 1.8%) Ab+ in March, to 6.2% (95%CI: 5.1%, 7.4%) PCR+ and 4.2% (95%CI: 3.3%, 5.3%) Ab+ in May. The highest SARS-CoV-2 prevalence was found in Hispanic individuals who made up 8.4% (95%CI: 7.4%, 9.4%) of individuals screened, but 35% (95%CI: 29%, 41%) of infections (PCR and/or Ab+). Demographic and clinical factors independently associated with acute infection included Hispanic ethnicity, loss of smell or taste, subjective fever, cough, muscle ache and fever. Factors independently associated with convalescent infection were Hispanic ethnicity and low oxygen saturation. Conclusions The burden of COVID-19 in Baltimore City increased dramatically over the 11-week study period and was disproportionately higher among Hispanic individuals. ED-based surveillance methods are important for identifying both acute and convalescent SARS-CoV-2 infections and provides important information regarding demographic and clinical correlates of disease in the local community.

Human brucellosis is a neglected zoonotic problem worldwide with a high degree of morbidity in humans and is mostly overlooked due to other febrile conditions. The aim of this study was to evaluate the sero-prevalence and risk factors of human brucellosis among subjects living in Punjab, Pakistan. In this cross-sectional study, human blood samples were collected from seven districts of Punjab, Pakistan. Information regarding personal data, demographic data and potential risk factors was collected through a structured questionnaire. Detection of anti-Brucella antibodies was done through Rose Bengal Plate Test (RBPT) and Enzyme Linked Immunosorbent Assay (ELISA). Descriptive analysis, Chi square test and Odds ratio was applied using STATA software version 12. The sero-prevalence of human brucellosis was 13.13% with significantly higher percentage in males 17.23% and age group 25-40 years 16.50% (P=< 0.001). The demographic factors positively associated with human brucellosis were lack of education (P = 0.003; OR = 1.85) and farming as an occupation (P =

ObjectiveTo evaluate pertussis antibody status of pregnant women and their newborns, and the impact of antenatal immunisation.DesignObservational study.SettingHospitals in urban western India.ParticipantsPregnant women and their newborns.MethodsPertussis antibody titres in mothers and their newborns were determined. Vaccinated and unvaccinated mothers and their newborns were compared for baseline characteristics, geometric mean titres (GMTs) and placental transfer ratio of antibodies. Multivariate logistic regression was performed to understand the influence of different factors on protective antibody titres.ResultsOf 284 mother–infant pairs, 75 mothers and 73 of their newborns were seropositive for anti-pertussis toxin (PT) IgG antibodies. 94 women were vaccinated in pregnancy; 51 (54.3%) of these mothers and newborns were PT IgG positive, compared with 24 (12.3%) of the women (and 22 newborns) not vaccinated in pregnancy. Women vaccinated in pregnancy and their newborns had higher GMT (30.88 and 32.54 IU/mL), compared with women who were not vaccinated (12.63%, 2.24 IU/mL) and their newborns (11.58%, 2.53 IU/mL). Placental transfer ratios in newborns of mothers vaccinated in pregnancy and those who had childhood immunisation or natural immunity were similar (1.05 and 1.12, respectively). Protective titres of antibodies at birth (>20 IU/mL) were observed in 72.3% vs 21% of newborns of vaccinated and unvaccinated pregnant women, respectively; influenced by mother’s vaccination status and seropositivity.ConclusionProtection against pertussis is low in newborns of mothers who are only immunised during childhood. Vaccination early in pregnancy boosts maternal and neonatal immunity.

Multiplex bead assays (MBAs) for serologic testing have become more prevalent in public health surveys, but few studies have assessed their test performance. As part of a trachoma study conducted in a rural part of Ethiopia in 2016, dried blood spots (DBS) were collected from a random sample of 393 children aged 0 to 9 years, with at least two separate 6-mm DBS collected on a filter card. Samples eluted from DBS were processed using an MBA on the Luminex platform for antibodies against 13 antigens of nine infectious organisms: Chlamydia trachomatis, Vibrio cholera, enterotoxigenic Escherichia coli, Cryptosporidium parvum, Entamoeba histolytica, Camplyobacter jejuni, Salmonella typhimurium Group B, Salmonella enteritidis Group D, and Giardia lamblia. Two separate DBS from each child were processed. The first DBS was run a single time, with the MBA set to read 100 beads per well. The second DBS was run twice, first at 100 beads per well and then at 50 beads per well. Results were expressed as the median fluorescence intensity minus background (MFI–BG), and classified as seropositive or seronegative according to external standards. Agreement between the three runs was high, with intraclass correlation coefficients of > 0.85 for the two Salmonella antibody responses and > 0.95 for the other 11 antibody responses. Agreement was also high for the dichotomous seropositivity indicators, with Cohen’s kappa statistics exceeding 0.87 for each antibody assay. These results suggest that serologic testing on the Luminex platform had strong test performance characteristics for analyzing antibodies using DBS.

Background In a country-wide seroprevalence study of COVID-19 in Estonia, we aimed to determine the seroprevalence and the dynamics of IgG against SARS-CoV-2 after vaccination or positive PCR-test. Methods Leftover blood samples were selected between 8 February and 25 March 2021, by SYNLAB Estonia from all counties and age groups (0–9, 10–19, 20–59, 60–69, 70–79 and 80–100 years) proportionally to the whole Estonian population and tested for IgG against SARS-CoV-2 spike protein receptor-binding domain (anti-S-RBD IgG) using Abbott SARS-CoV-2 IgG II Quant assay. Antibody levels after positive PCR-test or vaccination were described by exponential increase-decrease models. Results According to total of 2517 samples, overall seroprevalence (95% confidence interval [CI]) was 20.1% (18.5–21.7%), similar in all age groups, but varied between counties. If individuals vaccinated with the first dose at least 14 d before antibody measurement were assumed to be seronegative, the overall seroprevalence was 15.8% (14.4–17.3%), 4.0-fold larger than the proportion of PCR-confirmed COVID-19 cases. Of seropositive individuals (n = 506) 194 (38.3%; 33.8–43.1%) had not had positive PCR-test or been vaccinated. According to exponential increase-decrease model, the peak of anti-S-RBD IgG in a 52-year-old (median age of PCR-positive and/or vaccinated individuals) was significantly higher after vaccination compared with positive PCR-test (22,082 (12,897–26,875) vs. 6732 (2321–8243) AU/mL), but half-life was similar (26.5 (6.9–46.1) vs. 38.3 (8.2–68.5) d). Conclusions One year after the start of COVID-19 pandemic the actual prevalence of infection is still underestimated compared with PCR-confirmed COVID-19 cases. Older compared with younger individuals have lower anti-S-RBD IgG level after vaccination, but similar decline rate.

The question associated with efficacy and longevity of SARS-CoV-2 protection post-vaccination is paramount. The cPass surrogate virus neutralization test (sVNT) has gained popularity globally as a dual application assay for: 1. Accurate SARS-CoV-2 population surveillance (seroprevalence) analysis and 2. Revealing the presence of antibodies that block and effectively neutralize the interaction between the SARS-CoV-2 receptor binding domain and the host cell ACE2 receptor in recovered or vaccinated individuals. This study describes an approach for accurate quantification of neutralizing antibodies using the cPass sVNT with an automated workflow on the Tecan EVO and Dynex Agility platforms that is applicable to other liquid handling systems. This methodology was used to assess the stability of SARS-CoV-2 neutralizing antibodies between freeze/thaw and refrigerated sample storage conditions. Furthermore, a subset of twenty-five samples from SARS-CoV-2 infected/recovered individuals revealed a 600-fold difference in the neutralizing antibody response where low titers were represented in about half of the samples. Finally, pre- and post-vaccination samples were tested for neutralizing antibodies using the qualitative and semi-quantitative cPass sVNT protocols revealing undetectable or relatively low levels after the first vaccine dose and a decline in levels longitudinally over the months following the second dose. This wide range in neutralizing (blocking) antibodies from both natural infection and vaccination supports a differential immune response that may be attributed to several physiological and genetic factors underlining the potential for measuring SARS-CoV-2 neutralizing antibody titer levels post-vaccination to help ensure robust and prolonged immunity.

We previously detected a potentially novel reassortant of Crimean-Congo hemorrhagic fever virus in camels at the largest livestock market in the United Arab Emirates. A broader survey of large mammals at the site indicated zoonotic transmission is associated with dromedaries and camel ticks. Seroprevalence in cattle, sheep, and goats is minimal.

Background A cross‐sectional study was conducted from November 2018 to May 2019 to estimate seroprevalence of foot and mouth disease virus for cattle and assess associated risk factors in selected districts of afar region. Simple random sampling technique was employed to select the study areas. A total of 384 bovine sera were collected from 72 herds and seroprevalence of the disease was determined using 3ABC‐ELISA technique. Data were recorded and coded using Microsoft Excel spread sheet and analysed using STATA. Potential risk factors of the disease were also assessed using logistic regression analysis. Results Out of 384 sera tested at National Veterinary Institute, the overall seroprevalence of foot and mouth disease (FMD) virus was 19.8% (n = 76; 95% CI = 15.8‐23.79) at animal level and 56.94% at herd level. The herd level seroprevalence was higher in animals tested from Dubti (85%, n = 17) than Asayita (48.13%, n = 13) and Chifra (44%, n = 11). Among the associated risk factors, age, herd size, district and contact with wild life were statistically associated with foot and mouth disease serostatus (p, FMD was more prevalent and economically significant disease in the study districts.

Background Low vaccination rates and under-detection of pertussis infections in adolescents and young adults have an impact on the transmission of pertussis to infants. In this study, the proportion of adolescents and young adults with IgG antibodies against B. pertussis antigens, representing recent infection or vaccination, was estimated in a population-based probabilistic survey in Mexico. Methods Sera and data from 1,581 subjects, including 1,102 adolescents and 479 young adults (10–19 and 20–25 years old, respectively) randomly selected from Mexico’s 2012 National Health and Nutrition Survey, were analyzed. IgG antibodies against pertussis toxin (PT) were measured with the CDC/FDA ELISA. A subset of 234 samples was additionally tested with Bp-IgG PT ELISA kit (EUROIMMUN AG, Lubeck, Germany). Threshold values from corresponding test kits were used to identify recent infection or vaccination. Results Overall anti-PT IgG seroprevalence was 3.9% (95% CI: 2.3–6.3); 3.1% (95% CI: 1.9–5.0) in adolescents, and 4.9% (95% CI: 2.2–11) in young adults. Seroprevalence did not significantly vary by sex, socioeconomic status, region or rural/urban location. Compared to the CDC/FDA ELISA, the EUROIMMUN test showed a 76% sensitivity and 88% specificity. The weighted estimates represent a considerable burden of recent infection in adolescents and young adults; however, most adolescents and adults were seronegative and, therefore, susceptible to pertussis infection. Conclusion Since booster vaccination to B. pertussis after toddlerhood is not recommended in the Mexican national policy, anti-PT IgG seropositivity may be reasonably attributed to recent infection. Assessing pertussis seroprevalence requires careful consideration of the diagnostic test threshold interpretation and epidemiological model used.

ContextOn March 11, the World Health Organization (WHO) announced the current corona virus disease 2019 (COVID-19) outbreak as a pandemic. The first laboratory-confirmed case of COVID-19 in Austria was announced on February 27, 2020. Since then, the incidence of infection followed an exponential increase until a complete lockdown in March 2020. Thereafter easing of restrictions was gradually introduced and until mid-August daily infections remained mostly below 5 per 100.000 population.ObjectivesThe aims of this study are to determine i) how many employees in Austrian trauma hospitals and rehabilitation facilities have virus specific IgG and IgM, and/or neutralizing antibodies against SARS-CoV-2, ii) how many are active virus carriers (symptomatic and asymptomatic) during the study, iii) the antibody decline in seropositive subjects over a period of around six months, and iv) the utility of rapid antibody tests for outpatient screening.Study DesignOpen uncontrolled observational cross-sectional study.Setting/ParticipantsA total of 3301 employees in 11 Austrian trauma hospitals and rehabilitation facilities of the Austrian Social Insurance for Occupational Risks (AUVA) participated in the study.Study Interventions and MeasuresRapid antibody tests for SARS-CoV-2 specific IgG and IgM antibodies, and RT-PCR tests based on oropharyngeal swab samples, as well as laboratory-based antibody tests using ELISA/PRNT were performed. The tests were conducted twice, with an interval of 42.4±7.7 (Min=30, Max=64) days. Additionally, participants filled out a questionnaire including questions related to personal health, traveling activities, living situation, as well as inquiries of symptoms and comorbidities. Antibody positive tested participants were re-tested with ELISA/PRNT tests at a third time point on average 188.0±12.8 days after their initial test.ResultsIn our study cohort, only 27 out of 3301 participants (0.81%) had a positive antibody test at any time point during the study confirmed via neutralization test. Among participants who had positive test results in either of the antibody tests, 50.4% did not report any symptoms consistent with common manifestations of COVID-19 during the study period or within the preceding six weeks. In the group who tested positive during or prior to study inclusion the most common symptoms of an acute viral illness were rhinitis (21.9%), and loss of taste and olfactory sense (21.9%).The rapid antibody test was generally more sensitive based on serum (sensitivity=86.6%) as compared to whole blood (sensitivity=65.4). Concerning both ELISA tests overall the Roche test detected 24 (sensitivity=88.9%) and the Diasorin test 22 positive participants (sensitivity=81.5%).In participants with a positive PRNT, a significant decrease in PRNT concentration from 31.8±22.9 (Md=32.0) at T1 to 26.1±17.6 (Md=21.3) at T2 to 21.4±13.4 (Md=16.0) at T3 (χ2=23.848, df=2, p2=23.848, df=2, pConclusionsDuring the study period (May 11th – December 21th) only 0.81% were tested positive for antibodies in our study cohort. The antibody concentration decreases significantly over time with 14.8% (4 out of 27) losing detectable antibodies.

Enterovirus A71 (EV-A71) and coxsackievirus A6 (CVA6) cause hand, foot and mouth disease (HFMD) and are occasionally linked to severe neurologic complications and large outbreaks worldwide. We estimated EV-A71 and CVA6 seroprevalence using cross-sectional age-stratified samples collected in 2006, 2011, and 2017. Seroprevalences of EV-A71 and CVA6 increased from 32% and 54% at 6–11 months to >75% by 10 years of age. Antibody titers declined after 20 years, which could indicate infrequent re-exposure in older populations. Age profiles for acquiring infections and mean titers were comparable in the 3 testing years, despite the marked increase in incidence of CVA6-related HFMD from 2010. The uncoupling of changes in disease severity from the infection kinetics of CVA6 as we inferred from the seroprevalence data, rather than incidence of infection over the 11-year study period, provides further evidence for a change in its pathogenicity.

Background In pastoral and lowland areas of the country particularly in Afar region, studies suggested higher prevalence of contagious bovine pleuropneumonia (CBPP) than mid and highland agro‐ecologies. Though CBPP is a prime constraint to cattle productivity in the region, research outputs pertaining to CBPP are unavailable compared to highland areas. Thus, the objectives of the current study were to determine seroprevalence of CBPP and assess risk factors in selected districts of Afar region. Methods A cross‐sectional study was conducted on cattle aged 6 months and above from February 2018 to January 2019 in selected districts of the region. A total of 420 blood samples were collected and sera were separated for further serologic analysis. Using competitive enzyme linked immunosorbent assay (c‐ELISA), antibodies against Mycoplasma mycoides subspecies mycoides small colony (MmmSc) were detected at National Veterinary Institute, Ethiopia. Data were analysed using Stata version 14.0. Result Of 420 samples tested by c‐ELISA, 158 samples were found to be positive for CBPP providing an overall seroprevalence of 37.6%. Among the three risk factors considered (age, sex and district) assessed, only two (age and district) were found to be associated significantly with the disease (p, CBPP is an economically devastating cattle disease in pastoral and lowland areas of the country' in particularly Afar region

Objective The objective of this study was to determine the proportion of the Anambra State population that had been infected by the SARS-CoV-2 virus and developed antibodies before the second wave. Methods The WHO-recommended health facility-based cross-sectional approach was adapted for this survey. Between 8th and 15th December 2020, 3142 participants across the 21 local government areas (LGAs) of the State, aged one year and over, attending randomly selected health facilities, were recruited. Demographic and symptom-related information were collected from the participants as well as whole peripheral blood, which was tested for SARS-CoV-2 IgG and IgM with rapid test kits. Results 425 participants tested positive for IgG only, 74 for IgM only, while 54 were positive for both IgG and IgM. Overall, 553 positives were recorded, giving a crude seroprevalence of 17.6% (95% CI = 16.26 – 18.98). It ranged widely from 31.9% (95% CI = 24.43 – 40.22) in Onitsha North LGA to 5.4% (95% CI = 2.19 – 10.78) in Awka north. Bayesian Adjustments yielded a state seroprevalence of 16.1%. Conclusion One in six state residents had been infected by SARS-CoV-2 and developed antibodies before the second wave. All LGAs, age groups, sexes, and settlement types were affected by COVID-19. A large proportion of the population remained susceptible to SARS-CoV-2., Graphical Abstract Image, graphical abstract

After the first detection of Middle East respiratory syndrome coronavirus (MERS-CoV) in camels in Jordan in 2013, we conducted 2 consecutive surveys in 2014–2015 and 2017–2018 investigating risk factors for MERS-CoV infection among camel populations in southern Jordan. Multivariate analysis to control for confounding demonstrated that borrowing of camels, particularly males, for breeding purposes was associated with increased MERS-CoV seroprevalence among receiving herds, suggesting a potential route of viral transmission between herds. Increasing age, herd size, and use of water troughs within herds were also associated with increased seroprevalence. Closed herd management practices were found to be protective. Future vaccination strategies among camel populations in Jordan could potentially prioritize breeding males, which are likely to be shared between herds. In addition, targeted management interventions with the potential to reduce transmission between herds should be considered; voluntary closed herd schemes offer a possible route to achieving disease-free herds.

Background Animal and human brucelloses have been reported in Rwanda, human brucellosis being linked to drinking inadequately heat‐treated milk. However, information on Brucella detection and prevalence in milk produced in Rwanda is limited. Objectives To determine the sero‐prevalence and risk factors of Brucella in farm bulk milk from zero and open grazing cattle production systems in Rwanda. Methods A total of 330 farm bulk milk samples were collected from 198 zero grazing farms and 132 open grazing farms in a cross‐sectional study in Rwanda. Sero‐prevalence of Brucella in milk was analysed using indirect enzyme‐linked immunosorbent assay. A questionnaire was administered to farmers to determine the risk factors of milk contamination with Brucella. Results Anti‐Brucella antibodies were prevalent in 19.7% (95% confidence interval (CI), 15.5–24.4) of the 330 collected farm bulk milk. Sero‐prevalence was significantly higher (p, This is a cross sectional study which determined the sero‐prevalence and risk factors of Brucella prevalence in farm bulk milk in Rwanda. Brucella was found to be more prevalent in milk from open grazing farms, compared to milk from zero grazing farms. Practising open grazing system, histories of abortion and placenta retention were the significant risk factors for the presence of anti‐Brucella antibodies in farm bulk milk.

Introduction Healthcare workers (HCWs) in Saudi Arabia are a unique population who have had exposures to the Middle East Respiratory Syndrome coronavirus (MERS-CoV) and Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). It follows that HCWs from this country could have pre-existingMERS-CoV antibodies that may either protect from coronavirus disease 2019 (COVID-19) infection or cause false SARS-CoV-2 seropositive results. In this article, we report the seroprevalence of MERS-CoV and SARS-CoV-2 among high-risk healthcare workers in Riyadh city, Saudi Arabia. Methods This is a cross-sectional study enrolling 420 high-risk HCWs who are physically in contact with COVID-19 patients in three tertiary hospitals in Riyadh city. The participants were recruited between the 1st of July to the end of December 2020. A 3 ml of the venous blood samples were collected and tested for the presence of IgG antibodies against the spike proteins of SARS-CoV-2 and MERS-CoV using enzyme-linked immunosorbent assay (ELISA). Results The overall prevalence of SARS-CoV-2 in high-risk HCWs was 14.8% based on SARS-CoV-2 IgG testing while only 7.4% were positive by Polymerase Chain Reaction (PCR) for viral RNA. Most of the SARS-CoV-2 seropositive HCWs had symptoms and the most frequent symptoms were body aches, fever, cough, loss of smell and taste, and headache. The seroprevalence of MERS-CoV IgG was 1% (4 participants) and only one participant had dual seropositivity against MERS-CoV and SARS-CoV-2. Three MERS-CoV positive samples (75%) turned to be negative after using in-house ELISA and none of the MERS-CoV seropositive samples had detectable neutralization activity. Conclusion Our SARS-CoV-2 seroprevalence results were higher than reported regional seroprevalence studies. This finding was expected and similar to other international findings that targeted high-risk HCWs. Our results provide evidence that the SARS-CoV-2- seropositivity in Saudi Arabia similar to other countries was due to exposure to SARS-CoV-2 rather than MERS-CoV antibody.

We conducted a serosurvey for Crimean-Congo hemorrhagic fever virus antibodies in various wildlife species in Catalonia, northeastern Spain. We detected high seroprevalence in southern Catalonia, close to the Ebro Delta wetland, a key stopover for birds migrating from Africa. Our findings could indicate that competent virus vectors are present in the region. info:eu-repo/semantics/publishedVersion

Erysipelothrix rhusiopathiae (ER) is an old but still emerging zoonotic infection that is not yet completely understood. ER infects a wide range of species and wild boar is of significant interest because of their similarities to pigs, a known ER reservoir. Moreover, the increase of its densities and the limited data available about ER in this species should be considered. The need is to investigate whether wild boar could represent a risk of erysipelas at the wildlife-domestic-human interface. Here, 1067 sera and 149 tonsils of wild boar from five hunting districts in Northwest Italy were tested using ELISA and bacteriological culture, respectively. Using generalized linear models, we evaluated host and environmental factors influencing ER spread and dynamics. We found an ER seroprevalence of 69.4% among wild boar. Increased human density and pig farm density lead to an increase of ER seropositivity highlighting its association with anthropic environmental-related factors. The high ER percentage of isolation (34.2%) found in healthy wild boar suggests that this species can serve as a healthy carrier. This fact, together with the high seroprevalence, supports a role of wild boar as an ER reservoir. Potential zoonotic and economic risks should be considered in light of these data.

Objective: Patients with chronic rheumatic diseases (CRDs), such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), require special attention during the COVID-19 pandemic as they are considered at risk of severe infections. Our objective was to assess the seroprevalence of SARS–CoV-2 in patients with SLE and RA and to assess patient behavior, disease-related symptoms, and mental health. Methods: More than 900 participants were included: 405 patients with RA or SLE (CRD patients) and 513 blood donors. All participants had blood SARS–CoV-2 total antibodies measured (sensitivity 96.7%, specificity 99.5%) and answered a questionnaire concerning behavior, anxiety, and symptoms of depression (Patient Health Questionnaire 9). The CRD patients were further asked about physical activity, adherence to medication, and disease-related symptoms. Results: CRD patients had a significantly lower seroprevalence of SARS–CoV-2 antibodies (n = 1 of 365, 0.3%) compared to blood donors (n = 10 of 513, 1.9%; P = 0.03). Almost 60% of patients were unable to exercise as usual, and increased pain and disease activity was experienced by 34% and 24% of patients, respectively. Almost 10% of patients reduced or discontinued their immunosuppressive treatments at their own initiative. Symptoms of moderate depression were present in 19% of patients compared to 6.8% of blood donors (P < 0.001). Conclusion: Low seroprevalence in patients with CRDs indicates successful mitigation of exposure to SARS–CoV-2. However, this mitigation appears to occur at the expense of physical activity, experience of increased pain, disease activity, and symptoms of depression. There is a need for care providers to be aware of these negative side effects and for further studies to investigate the possible long-term consequences.