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We identified a cluster of mpox exposures among key populations in Kenya through retrospective serologic screening. We identified strong seropositivity among sex workers and gay, bisexual, and other men who have sex with men. These findings demonstrate the need for increased mpox surveillance among mpox-endemic and mpox-endemic-adjacent regions in Africa.

The Zika virus (ZIKV) epidemic in Latin America (2015–2016) has primarily been studied in urban centers, with less understanding of its impact on smaller rural communities. To address this gap, we analyzed ZIKV seroepidemiology in 6 rural Ecuadorian communities (2018–2019) with varying access to a commercial hub. Seroprevalence ranged from 19% to 54%, measured by nonstructural protein 1 blockade of binding enzyme-linked immunosorbent assay. We observed a decline in ZIKV seroprevalence between 2018 and 2019 that was greater among younger populations, suggesting that the attack rates in the 2015–2016 epidemic were significantly higher than our 2018 observations. These data indicate that the 2015–2016 epidemic included significant transmission in rural and more remote settings. Our observations of high seroprevalence in our area of study highlights the importance of surveillance and research in rural areas lacking robust health systems to manage future Zika outbreaks and vaccine initiatives. [ABSTRACT FROM AUTHOR]

There is an increasing global burden from chikungunya virus (CHIKV). Bangladesh reported a major epidemic in 2017, but it was unclear whether there had been prior widespread transmission. We conducted a nationally representative seroprevalence survey in 70 randomly selected communities immediately before the epidemic. We found that 69 of 2938 sampled individuals (2.4%) were seropositive to CHIKV. Seropositivity to dengue virus (adjusted odds ratio, 3.13 [95% confidence interval, 1.86–5.27]), male sex (0.59 [.36–.99]), and community presence of Aedes aegypti mosquitoes (1.80 [1.05–3.0]7) were significantly associated with CHIKV seropositivity. Using a spatial prediction model, we estimated that across the country, 4.99 (95% confidence interval, 4.89–5.08) million people had been previously infected. These findings highlight high population susceptibility before the major outbreak and that previous outbreaks must have been spatially isolated. [ABSTRACT FROM AUTHOR]

Background: Chad with 7,698 confirmed cases of infection and 194 deaths since the beginning of the COVID-19 pandemic, is one of the African countries with the lowest reported case numbers. However, this figure likely underestimates the true spread of the virus due to the low rate of diagnosis. The high rate of asymptomatic infections reflects the reality of SARS-CoV-2 transmission in Chad. In this study, we estimated the seroprevalence and identified factors associated with SARS-CoV-2 infection. Methods: A cross-sectional study was conducted between September 2022 and February 2023. A total of 1,290 plasma samples were collected from outpatient attendees at Health Facilities located in 11 provinces of Chad and tested by ELISA method, for the presence of IgG antibodies to SARS-CoV2 nucleocapsid (N) protein. KoboToolbox was used to gather data from the participants and data were analyzed using STATA 16. Results: The overall seroprevalence was 83.0% [95% CI = 81.6%—85.5%], with variations between provinces, ranging from 99.2% [95% CI = 94.0%—100%] in Moundou (Southern Chad) to 46.8% [95% CI = 36.0% -57.1%] in Biltine (Eastern Chad). Factors associated with the seroprevalence included military occupation (OR = 0.37 CI [0.80–1.77] p = 0.025) and age group between 55–64 years (OR = 0.33 CI [0.15–0.72] p = 0.005). While, other factors, such as gender and age were not significantly associated with seroprevalence. Conclusion: Our results indicated that, the seroprevalence of COVID-19 in Chad is among the highest in Sub-Saharan Africa. These estimates could guide the response and public health policy decisions, enhancing the management of future outbreaks involving respiratory pathogens. [ABSTRACT FROM AUTHOR]

ABSTRACT The COVID‐19 infection fatality rate (IFR) is the proportion of individuals infected with SARS‐CoV‐2 who subsequently die. As COVID‐19 disproportionately affects older individuals, age‐specific IFR estimates are imperative to facilitate comparisons of the impact of COVID‐19 between locations and prioritize distribution of scarce resources. However, there lacks a coherent method to synthesize available data to create estimates of IFR and seroprevalence that vary continuously with age and adequately reflect uncertainties inherent in the underlying data. In this article, we introduce a novel Bayesian hierarchical model to estimate IFR as a continuous function of age that acknowledges heterogeneity in population age structure across locations and accounts for uncertainty in the estimates due to seroprevalence sampling variability and the imperfect serology test assays. Our approach simultaneously models test assay characteristics, serology, and death data, where the serology and death data are often available only for binned age groups. Information is shared across locations through hierarchical modeling to improve estimation of the parameters with limited data. Modeling data from 26 developing country locations during the first year of the COVID‐19 pandemic, we found seroprevalence did not change dramatically with age, and the IFR at age 60 was above the high‐income country estimate for most locations. [ABSTRACT FROM AUTHOR]

Strongyloides stercoralis is a soil‐transmitted helminth which is distributed predominately throughout tropical and subtropical regions and is considered a neglected tropical disease. Due to low larval output, traditional microscopic methods lack sensitivity, especially in areas of low endemicity. Serological assays present an opportunity to study the epidemiology of S. stercoralis in areas of low endemicity such as Jamaica. The current study evaluated the seroprevalence of S. stercoralis in a selected subpopulation in Jamaica. An analysis was conducted on 311 archived serum samples previously submitted for investigating viral infections during a fever epidemic between 2014 and 2015. Randomly selected, anonymized sera were tested for the presence of S. stercoralis IgG antibodies using the AccuDiag Strongyloides IgG ELISA Kit. Data including age, sex, clinical diagnosis, and the geographic location of sample submission were recorded to delineate trends in demographic variables. The seropositivity rate of S. stercoralis was 15.43%. The rate among females and males was 16.45% and 14.47%, respectively (χ2 = 0.2339, p = 0.629). The highest rate was found in middle adulthood (31–50 years) (26.53%; 13/49). The seroprevalence of S. stercoralis was significantly highest in a rural Regional Health Authority (33.33%; 14/42) and least within an urban Health Authority (9.71%; 17/175). Exposure to S. stercoralis appears to be highest in the rural Regional Health Authorities with an island‐wide exposure rate of 15.43%. The rapid ELISA testing method for the detection of IgG antibodies to S. stercoralis used in this study may be useful as part of a combined approach to elucidate the epidemiology of this soil‐transmitted parasite in Jamaica. [ABSTRACT FROM AUTHOR]

Porcine deltacoronavirus (PDCoV) is an infectious disease that causes diarrhoea in pigs of different ages; however, piglets are more susceptible. PDCoV was first reported in 2012 in China and Hong Kong. Later, it was first reported in the USA in 2014 and in Mexico in 2019. Several studies have shown that M protein is highly conserved and, therefore, suitable for diagnostic systems. In this study, for the first time, an indirect enzyme‐linked immunosorbent assay (iELISA) based on a recombinant M protein (rM‐PDCoV) was developed to evaluate the seroprevalence of PDCoV in four states in Mexico. High sensitivity (83%) and specificity (100%) were observed for the iELISA. The kappa index calculated a nearly perfect agreement (0.8831) compared to the Western blot (gold standard test), suggesting acceptable statistical value support. In this study, 50.38% of the serum samples from backyard pigs were PDCoV‐positive. The serological comparison showed that PDCoV/PEDV coinfections occurred in 31.98% of the analysed sera. These results can enrich our understanding of how this virus spreads and enable the evaluation of PDCoV infections. Moreover, it highlights the importance of continually investigating the seroprevalence of PDCoV in Mexico because there is also no information about the current prevalence of the disease. [ABSTRACT FROM AUTHOR]

The guinea fowl (Numida meleagris) holds significant agricultural importance in Ghana, particularly in the Northern, Upper East and Upper West Regions. Despite their economic and cultural significance, guinea fowls face a potential threat from avian influenza, a global concern for its adverse impact on poultry populations. This study assessed the seroprevalence of the virus in mature guinea fowls in the Upper East Region. A cross‐sectional survey was conducted in three districts within the Upper East Region from April to June 2023. Blood samples were collected from 397 guinea fowls that are over 4 weeks old, and seroprevalence was determined using ID Screen Influenza A Antibody Competition Enzyme‐linked immunosorbent assay (ELISA). The study analysed demographic factors such as sex, age and source of birds, employing statistical methods to establish associations. Among the sampled guinea fowls, 24.7% tested positive for avian influenza antibodies, whereas 75.3% were seronegative. Age did not show statistically significant associations with seroprevalence, but intriguing patterns were observed. Adult guinea fowls exhibited higher seroprevalence (23.7%) compared to growers (1.0%). The source of birds showed no significant association, but birds from slaughter points demonstrated higher seroprevalence (11.6%) compared to households (5.0%) and live bird markets (8.1%). In conclusion, the study underscores the importance of monitoring avian influenza in guinea fowls to implement effective control measures. The presence of antibodies suggests guinea fowls may contribute to virus transmission in the Upper East Region. The study recommends ongoing nationwide surveillance to assess the true prevalence of avian influenza in guinea fowls across Ghana. [ABSTRACT FROM AUTHOR]

Objectives: People living with HIV (PLWH) are a risk group for severe symptoms and higher mortality during COVID-19. We analyzed the dynamic rise of SARS-CoV-2 seroprevalence induced by coinfections and vaccinations in PLWH in the first three years of the pandemic in Germany and compared it with corresponding data available for the general population. Methods: Each month on average 93 blood samples from the German HIV-1 Seroconverter Cohort, a prospective longitudinal multicenter study that includes PLWH whose date of seroconversion is well defined, were received. The samples from 1569 PLWH were tested for the presence of anti-S1 and if positive, also for anti-N antibodies. Results: In 2020 the number of anti-S1 positive cases/month was between 0.0 and 6.9% (average 1.6%). Since then the anti-S1 prevalence increased reaching already 35% (33/94) in May 2021. At that time 3.2% of the cases were also anti-N positive. In 2022 the average anti-S1 seroprevalence reached 97.5%. In the vaccination era a positive anti-N response was associated with a younger age and females were overrepresented among anti-S1/anti-N negative samples (assuming no vaccination or infection). Conclusions: The average 1.6% anti-S1 seroprevalence in the cohort in 2020 was comparable to that in the general population (1.3%). The increase in anti-S1 seroprevalence in the first half of 2021 occurred slightly earlier. This increase was likely caused by the prioritization of PLWH at the early stage of the vaccination campaign and by infections during the third wave of the pandemic. [ABSTRACT FROM AUTHOR]

Background: Until 2005, when a single dose of vaccine was implemented in one-year-old children, the Hepatitis A virus (HAV) was responsible for approximately 90% of acute hepatitis cases in the paediatric population in Argentina. However, despite vaccination success, sporadic outbreaks of HAV still occur among adults. This study aimed to assess the seroepidemiology of HAV in Argentina, analysing IgG and IgM antibodies against HAV in a large population, both vaccinated and unvaccinated. Methods: The study included 16,982 patients attending a hospital from 2001 to 2023. The cohort was divided into two groups: 16,638 individuals who were not reached by the vaccination program implemented in 2005 and 344 children who were covered by the universal vaccination. Results: Anti-HAV IgG was detected in 56.7% of cases. The rate was significantly higher in individuals born after 2005 (77.7%) compared to those born before (56.3%), p < 0.001. The age groups 19–40 and 41–60 years showed the anti-HAV IgG lowest rates. On the other hand, 100/3956 cases (2.5%) with suspected acute hepatitis were positive for Anti-HAVIgM. Notably, none of these were born after the mandatory vaccine rollout. Conclusions: The study of this large cohort contributes to the understanding of the seroepidemiology of HAV. Although the implementation of the vaccine achieved its main goal, the age segment between 19 and 60 years does not reach the estimated threshold to achieve herd immunity. These findings reveal the importance of targeting vaccination campaigns, provide essential insights for public health planning, and guide future immunisation strategies against HAV in Argentina. [ABSTRACT FROM AUTHOR]

Background: Understanding the dynamics of SARS-CoV-2 reinfections is crucial for public health policy, vaccine development, and long-term disease management. However, data on reinfections in the general population remains scarce. Objectives: This study aimed to investigate SARS-CoV-2 antibody dynamics among Austrian blood donors, representing healthy adults, over two years following primary infection and to evaluate the reinfection risk. Methods: 117,895 blood donations were analysed for SARS-CoV-2 total anti-N levels from June 2020 to December 2023. We examined anti-N and anti-S antibody dynamics and in vitro functionality in 230 study participants at five defined times during 24 months, assessing associations with demographics, vaccination status, and reinfection awareness. Results: The seroprevalence of SARS-CoV-2 infection-derived anti-N antibodies increased over time, reaching 90% by February 2023 and remaining at that level since then. According to serological screenings, we found an 88% reinfection rate, which is in contrast to participants' reports indicating a reinfection rate of 59%. Our data further reveal that about 26% of reinfections went completely unnoticed. Antibody dynamics were independent of age, sex, and ABO blood group. Interestingly, individuals with multiple reinfections reported symptoms more frequently during their primary infection. Our results further show that vaccination modestly affected reinfection risk and disease course. Conclusion: SARS-CoV-2 reinfections were uncommon until the end of 2021 but became common with the advent of Omicron. This study highlights the underestimation of reinfection rates in healthy adults and underscores the need for continued surveillance, which is an important support for public health policies and intervention strategies. [ABSTRACT FROM AUTHOR]

Background: Health care workers (HCWs) are front line responders to the COVID-19 pandemic, but limited data is available for pediatric HCWs, as the research response has largely focused on adult patients and medical personnel that treat these patients. Methods: We conducted a cross-sectional study of SARS-CoV-2 seroprevalence and risk factors in HCWs at a Children's Hospital in CO, USA from September 2020 to April 2021. Pediatric HCWs were defined as clinical care providers and administrative staff. Seroprevalence was determined using the Epitope SARS-CoV-2 anti-Nucleocapsid IgG assay (San Diego, CA) and the Euroimmun SARS-CoV-2 anti-Spike Protein IgG assay. Risk factors and vaccination status were assessed via questionnaire. Results: Overall, 110 HCWs were enrolled, 79 subjects were positive for anti-S antibodies and negative for anti-N antibodies, indicating COVID-19 vaccination. 31 subjects had neither anti-N or anti-S antibodies, indicating no exposure to SARS-CoV-2 and no vaccination. 3/110 had a nucleocapsid serology consistent with a SARS-CoV-2 prior infection. Seroprevalence was observed at 2.7%. It was noted that asthma requiring medication was associated with positive serostatus. Conclusions: During the winter 2020/21, SARS-CoV-2, we found a 2.7% seroprevalence of pediatric HCW at a children's hospital in Colorado. We compared this with publicly available seroprevalence data for seroprevalence rates of pediatric HCWs globally. This suggests that this specific children's hospital COVID-19 personal protective equipment (PPE) and infection control guidelines were effective in limiting SARS-CoV-2 in hospital transmission at the children's hospital prior to the presence of the Delta variant. [ABSTRACT FROM AUTHOR]

Introduction: Feline calicivirus (FCV) commonly causes upper respiratory tract, oral and ocular infections in species of the family Felidae, with high prevalence amongst domestic cat (Felis catus) populations worldwide. Detection of FCV‐specific antibodies in serum provides evidence of previous infection with FCV and an indication of whether a cat may be protected against clinical FCV disease. This study describes the most extensive sampling for anti‐FCV antibodies in feral and stray cat populations in Australia, and examines variation in prevalence associated with cat age, sex and location. Methods: Blood samples were opportunistically collected from 669 feral, stray or Indigenous community cats from the Northern Territory, South Australia, Victoria, south‐east Tasmania and south‐west New South Wales. The sera were harvested and tested for antibodies capable of neutralising the FCV vaccine strain F9 by serum‐virus neutralisation assay. Results: Of the 669 cats tested, 69.7% had detectable FCV‐F9‐neutralising antibodies (titres ≥5). Maturity was significantly associated with higher seroprevalence and higher antibody titres, with adult cats being more than twice as likely to have detectable FCV‐neutralising antibodies than subadults. Male cats had a higher seroprevalence and slightly higher antibody titres than females. Cats living in closer proximity to humans had significantly higher seroprevalences and higher FCV‐neutralising antibody titres than feral cats from more remote regions of Australia. Conclusion: Australian feral and stray cats have a high risk of natural exposure to and infection with FCV, with the prevalence and levels of pre‐existing immunity to FCV being highest amongst adult cats living in highly modified urban, peri‐urban and agricultural environments. [ABSTRACT FROM AUTHOR]

Lyme borreliosis (LB), the most common tick‐borne disease in Europe, is endemic to southern coastal Norway. LB commonly presents as erythema migrans, which can disseminate, resulting in more severe disease such as Lyme neuroborreliosis or arthritis. In Norway, public health LB surveillance is conducted via mandatory reporting of laboratory‐confirmed disseminated cases. From 2012 to 2022, Norway's surveillance‐reported incidence of laboratory‐confirmed disseminated LB increased by 78%. Although surveillance provides estimates of the incidence of disseminated LB, this study sought to estimate the incidence of symptomatic LB to better understand Norway's LB disease burden. Two studies were identified that, when combined, estimated an LB seroprevalence of 6.8% in the general adult population in southern Norway. Utilizing data from these seroprevalence studies, public health surveillance, and results from literature searches indicating that 37% of seroconverted LB cases are symptomatic and that the duration of LB antibody detection ranges from 10 to 20 years, we estimated that there were 315–630 symptomatic LB cases per 100,000 adult population in five southern coastal counties in Norway in 2022 and 24–48 cases of symptomatic LB for every public health surveillance‐reported LB case in adults in these five counties in Norway. [ABSTRACT FROM AUTHOR]

Aims: Hepatitis E caused by the hepatitis E virus (HEV) is prevalent worldwide. In China, considerable shifts in the epidemiology of hepatitis E have been observed over the last two decades, with ongoing changes in the prevalence of HEV. Method s : This study, in conjunction with the health examinations for students and workers, aims to estimate the seroprevalence and assess the risk factors of HEV infection in general population in Hebei province, China. Epidemiological information was collected using a specific questionnaire and blood samples were collected from each participant during the process of health examination. Anti‐HEV IgG and IgM in sera were tested using the Wantai ELISA assay kits. Logistic regression modelling was used to identify associated risk factors. Results: The average positive rate of anti‐HEV IgG in students (6–25 years) was 3.4%. One (0.2%) student was anti‐HEV IgM positive, while also testing positive for IgG. The HEV seroprevalence was not related to students' gender, school, or family residence. In occupational populations, the overall seropositivity rate was 13.3% for anti‐HEV IgG and 0.67% for IgM. HEV seropositivity increased significantly with age, ranging from 3.8% to 18.6% in age groups, and differed significantly among four occupation groups: farmers (17.6%), food supply workers (18.0%), other non‐farm workers (14.7%) and healthcare workers (5.9%) (p = 0.002). Multivariable logistic analysis confirmed the significant correlations of seroprevalence with age and occupation. Conclusions: The study found a low seroprevalence of HEV in children and young adults in Hebei Province, China. Advanced age correlates with higher seroprevalence in occupational populations, indicating an accumulation of HEV infection over time. Seroprevalence varied significantly among different occupation groups, suggesting the important role of occupational exposure for HEV infection. [ABSTRACT FROM AUTHOR]

Avian metapneumovirus (aMPV) poses a significant global threat to the respiratory and reproductive systems of poultry, yet its prevalence and impact in specific regions, such as northern Thailand, remain understudied. This study is the first comprehensive assessment of aMPV seroprevalence among layer hens in the region. By the application of Enzyme-Linked Immunosorbent Assay (ELISA), our findings reveal a high overall seroprevalence of 60.78%, with significantly higher rates among post-laying hens (70.87%) compared to pre-laying hens (47.02%). Regional variations were noted, Uttaradit province showing the highest seroprevalence at 74%. Factors such as overcrowded conditions and poor farm hygiene were implied as contributors to increased seropositivity. Comparison with global studies highlights aMPV’s endemicity and emphasizes the need for targeted surveillance and biosecurity measures. Migratory birds were inferred as potential vectors, contributing to the spread of aMPV across different regions. This study provides crucial epidemiological data essential for optimizing vaccination strategies and enhancing disease management practices to safeguard poultry health and sustainable production in northern Thailand. [ABSTRACT FROM AUTHOR]

Background Infections may contribute to Alzheimer's disease (AD) risk. Limited evidence suggests Toxocara spp. infection/exposure could influence AD development. Methods We investigated Toxocara seropositivity and AD in Iranian adults using a matched case–control study. Our sample included 90 AD cases and 91 healthy older adults. Anti- Toxocara immunoglobulin G (IgG) antibodies were assessed via enzyme-linked immunosorbent assay. We computed the odds ratios (ORs) and 95% confidence intervals (CIs) through univariable and multivariable analyses, adjusting for potential confounders. Results There were 33/90 (36.67% [95% CI 26.75 to 47.48]) anti- Toxocara IgG seropositive individuals identified among the AD cases and 21/91 (23.07% [95% CI 14.89 to 33.09]) among the healthy controls. In univariable analysis, a significant association was identified between anti- Toxocara IgG seropositivity and AD (OR 1.93 [95% CI 1.01 to 3.69], p<0.001). Moreover, the association remained significant (OR 2.18 [95% CI 1.05 to 4.49], p<0.001) in multivariable analysis after adjustment for covariates. There was no association between anti- Toxocara IgG seropositivity and the severity of AD (OR 0.75 [95% CI 0.21 to 2.61], p=0.47). Conclusions Our findings indicated that Toxocara exposure/infection could be a potential risk factor for development of AD. To better understand a real causality between Toxocara exposure/infection and AD and related dementias, follow-up designed and adequately powered studies are needed. [ABSTRACT FROM AUTHOR]

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High levels of pre-existing antibodies are amajor challenge for the application of viral vectors since they can severely limit their efficacy. To identify promising candidates among adeno-associated virus (AAV) based vectors for future gene therapies for the treatment of hereditary neuromuscular disorders (NMDs), we investigated the antibody levels in sera from patients with NMDs against 18 AAV types, including 11 AAVs with wild-type capsids, 5 AAVs with peptide-modified capsids and 2 AAVs with shuffled capsids. With regard to the wild-type capsid AAVs, the lowest binding antibody levels were detected against AAV6, AAV5, AAV12 and AAV9, whereas the highest binding antibody levels were detected against AAV10, AAV8, AAV1, and AAV2. The lowest neutralizing antibody levels againstwild-type AAVs were detected against AAV12, AAV5, AAV9, AAV7, AAV8 and AAV10, and the highest neutralizing antibody levels were detected against AAV13, AAV2 and AAV3. Interestingly, the influence of peptide modifications or shuffling of AAV capsids on antibody binding and AAV neutralization seemed to depend on the parental AAV. While the sex of the serum donors had no significant impact on binding or neutralizing antibody levels, we observed a trend to higher binding antibodies in older serum donors against some AAV types and a clear positive correlation of neutralizing antibody titers with the age of the serum donors. The disease status on the other hand did not have a meaningful impact on antibody levels, with no changes in AAV neutralization. Our data indicate that several wild-type or peptide-modified AAV may be good candidates for therapeutic application due to low pre-existing antibody levels, and that the age of potential recipients rather than their health status with regard to NMDs has the biggest impact on vector applicability. [ABSTRACT FROM AUTHOR]

Hepatitis C virus (HCV) transmission remains a significant public health concern. It is well documented globally, however, Nowshera district, Pakistan, is lacking such profile. This study aims to explore the relationship between HCV infection and several risk factors, including socio-demographic, clinical and personal life-style factors. This study using a cross-sectional design, examined 606 randomly selected individuals visiting the Pathology department at Qazi Hussain Medical Complex and District Headquarter (DHQ) Hospital Nowshera between May 1, 2022 and Jun 30, 2023. This research investigation employed a methodical approach involving formal interviews in conjunction with structured questionnaires to gather comprehensive information related to socio-demographic characteristics, clinical history, and personal hygiene practices. We collected 10 ml of blood samples and tested the separated serum to identify markers using the Immuno-Chromatographic Test (ICT) and the Enzyme-Linked Immunosorbent Assay (ELISA). IBM SPSS Statistics version 27 was used for data analysis. To measure the association between dependent variable and independent variables, a chi-square and risk analysis was carried out; multiple logistic regression was employed for modeling the risk factors associated with independent variable. A statistical significance level was established at a P-value of less than 0.05. In present study, which included 606 participants, 12% were found to be infected with HCV. Importantly it revealed that facial shave at barber (adjusted odds ratio, aOR = 40.65, p = 0.000) represents the most prevalent mode of HCV transmission. Additionally, a strong association was observed between HCV infection and history of past surgery (RR = 2.98, p = 0.001), HCV infected family member (aOR = 4.28, p = 0.001), workplace injuries (aOR = 6.68, p = 0.000), history of hospital admission (RR = 2.09), practicing ear and nose piercing (aOR = 5.01, p = 0.001), dental treatment (RR = 2.31) and the frequency of injections (aOR = 8.607, p = 0.000). These findings underscore the pressing need for targeted interventions. This study highlights the paramount importance of understanding the modes of HCV transmission and their associated risk factors. The results emphasize the need for educational initiatives, both within the healthcare sector and among the general public, to combat HCV transmission effectively. By implementing sterilization procedures and increasing awareness, we can make significant strides in reducing the burden of HCV infection. Moreover, proactive measures within families can help contain the spread of the virus, ultimately contributing to improved public health. [ABSTRACT FROM AUTHOR]

Introduction: The development of a potent immune response and antibodies against SARS-CoV-2 is important for herd immunity. The serological response may be due to a previous infection or vaccination. Healthy blood donors could represent and provide information on the immune status of the general population. Therefore, we estimated the global and regional prevalence of SARS-CoV-2 antibodies among healthy blood donors. Methods: We conducted a systematic search of PubMed, Scopus, and ProQuest from December 2019 to January 2023. After critical appraisal and quality assessment, a qualitative synthesis of the identified relevant articles was performed. The random-effects model was used to estimate the pooled prevalence of SARS-CoV-2 antibodies. Funnel plots and Egger's test were used to assess publication bias. Sensitivity analysis was performed, and heterogeneity was quantified using I2 statistics. Results: A total of 70 peer-reviewed articles were selected that together included 2,454,192 blood donors. The global estimated pooled prevalence of SARS-CoV-2 antibodies among healthy blood donors was 10.3% (95% CI: 4.6 – 18.0%, n = 70). The highest seroprevalence was observed in Asia (17.7%), followed by Africa (16.1%). The seroprevalence in studies conducted before the introduction of the vaccine was 6.1%, whereas those of studies conducted after vaccines were available was 27.6%. High seroprevalence was observed in studies that measured antibodies against the S protein of the virus (15.2%), while lower (12.5%) in those that measured antibodies against the N protein. A high seroprevalence was observed in studies that only measured IgG antibodies (16.3%), and it was 5.9% in studies that measured total antibodies. Conclusion: The prevalence of SARS-CoV-2 antibodies among healthy blood donors varies, potentially indicating geographical disparities in transmission and vaccination rates. To enhance community resilience, addressing these differences through inclusive health policies and adaptable public health measures is crucial. [ABSTRACT FROM AUTHOR]

Background: Camelpox is a common viral disease of camelids caused by camelpox virus, which is endemic in most camelid-breeding countries including Ethiopia, and causes major economic losses. This study aimed to quantify the seroprevalence of camelpox and identify associated risk factors to put into practice efficient control strategies for the disease in the study area. Methods: A cross-sectional study was carried out between January and July of 2023. Blood samples were collected from 374 camels of 75 households residing in two districts in six peasant associations. A sandwich enzyme-linked immunosorbent assay was employed to detect camelpox-specific antibodies from sera samples. To identify potential risk factors, camel owners were asked in face-to-face interviews. Results: The overall seroprevalence of camelpox in the study areas was 16.0% (95% confidence interval: 12.0%-20.0%). A multivariable logistic regression analysis revealed risk factors season, age, and sex had an association with seroprevalence of camelpox (p < 0.05). Sex was strongly associated with camelpox seropositivity, with female camels having a 3.2-fold higher risk of infection than male camels. Likewise, age-related vulnerability to infection was observed in young dromedaries, as they were 2.3 times more likely to become infected than adults. Conclusion: This study revealed moderate seroprevalence of camelpox in the study area. Thus, effective preventative strategies, such as vaccination programs to stop the spread of camelpox and reduce the financial losses caused by the disease, should be encouraged. [ABSTRACT FROM AUTHOR]

Carcasses of wild mammals provide convenient samples for wildlife disease investigators. Specifically, antibodies can persist in the blood and tissues of animals up to a few days after death and can provide information on exposure to specific pathogens, including microorganisms with zoonotic implications, such as Toxoplasma gondii, Trichinella spp., Brucella spp., and Mycobacterium spp. Although screening samples from decaying wildlife for antibodies is not a new method, an overview of the literature with clear recommendations on best practices is lacking. Here, we present results from a systematic review of 115 studies using enzyme‐linked immunosorbent assay (ELISA) to detect pathogen antibodies in wild mammals across 298 individual research projects. We discuss the range of mammalian hosts and the pathogens most represented in the literature and suggest improvements to consider when using samples from decaying animals for seroinvestigation. Our results indicate that the most examined mammals were artiodactyl ungulates and that antibodies against the bacteria Brucella spp. are those most examined to date, followed by the protozoan Toxoplasma gondii, malignant catarrhal fever virus, Schmallenberg orthobunyavirus, and the coccidian Neospora caninum. The effect of haemolysis in serum samples on ELISA results was considered in only 3.7% of the research projects we reviewed, sample size decisions were not outlined in 83% of research projects, and half of the projects did not examine seroprevalence in different age classes. Nevertheless, these details are important for replicability and accurate interpretation of results. We highlight the benefits and limitations of detecting antibodies against pathogens in carcasses from wild mammalian groups. Wild mammals are reservoirs for a wide range of pathogens including those with zoonotic potential and investigating their carcasses can help wildlife investigators to better understand the epidemiology of many diseases with implications for wildlife, livestock, and human health. [ABSTRACT FROM AUTHOR]

Introduction: High-risk human-papilloma viruses 16 and 18 (HR-HPV 16 and HR-HPV-18) are well known to be associated with carcinoma of the cervix, head and neck, penis, and anus. Low-risk human papillomaviruses 6 and 11 (LR-HPV 6 and LR 11) infection has been associated with anogenital warts, oral papilloma, and laryngeal papillomatosis in children. HPV infection during pregnancy (HR-HPV and LR-HPV) increases the risk of vertical transmission from infected pregnant women to unborn children. The burden of HR-HPV type 16 and 18 and LR-HPV 6 and 11 is not well documented among pregnant women attending antenatal clinics (ANC). This study determined the seroprevalence and distributions of HR-HPV 16, 18, and LR –HPV 6, 11 antibodies among pregnant women attending ANC at Bugando Medical Centre (BMC) in Mwanza, Tanzania. Methodology: A cross-sectional study involving 255 pregnant women enrolled in obstetrics and gynecology outpatient clinics was conducted between November 2020 and March 2021 at Bugando Medical Centre (BMC) in Mwanza. A structured pre-tested questionnaire was used to obtain patients' information. Sandwich Enzyme-Linked Immunosorbent Assay (ELISA) was used to detect HPV 6, 11, 16 and 18 specific immunoglobulin G (IgG) from sera. Stata version 15v1 was used for the descriptive data analysis. Results: The median age was 27(IQR: 22–31) years. The overall HPV seropositivity for any of the four serotypes was 63.9% (165/255), 95% CI: 58.0-69.7, whereby 37.6%(97/255), 32.2%(83/255), 15.5% (40/255) and 27.1% (70) were positive for HPV 6, 11, 16 and 18 respectively. Eight participants (3.1%) were positive for all 4 genotypes. Conclusion: About two-thirds of pregnant women had antibodies against HPV 6, 11 16, and 18 indicating previous HPV exposure. Vaccination programs should be emphasized to reduce the HPV-related manifestations in this population. [ABSTRACT FROM AUTHOR]

Background: Yellow fever virus (YFV) and dengue virus (DENV) are among the major re-emerging arboviruses that pose a significant threat to public health. Their associated burden and prevalence can be substantially underestimated due to insufficient surveillance and inadequate diagnosis. This study aimed to determine evidence of dengue, yellow and related flaviviruses circulation among the rural human populations residing in Nguruman (Kajiado County) and Kerio Valley (Baringo County), two dryland ecosystems in the Kenyan Rift Valley. Methods: Serum samples obtained from febrile patients between 5 and 85 years through a hospital-based cross-sectional survey from July 2020 – May 2023, were screened for neutralizing antibodies to YFV, DENV-2 and related flaviviruses, West Nile virus (WNV) and Zika virus (ZIKV) via Plaque reduction neutralization test (PRNT). The study sites and important demographic characteristics were obtained using a structural questionnaire and the data analyzed and seroprevalence compared. A multinomial logistic regression model was done to predict risk for each of the most prevalent viruses with covariates; age, gender, and occupation. Results: Overall, 54.5% (50.1–59.0% 95% confidence interval (CI) of the samples tested positive for at least one of the four Flaviviruses. The percentage was significantly higher in Kerio Valley (64.34%, 184/286) than in Nguruman (40.2%, 78/194) (P<0.0001). YFV had the highest prevalence, followed by WNV (16.25%), ZIKV (5.2%), and DENV-2 (1%). Kerio Valley had a significantly higher YFV seroprevalence (51%) than Nguruman (6%) (P<0.0001), while DENV-2 was observed only in Nguruman with a low seropositivity of 2%. In contrast to Nguruman, where seropositivity rates were higher in males at 47.47% (P=0.049), in Kerio Valley, females showed considerably higher viral seropositivity at 60.82% than males (P<0001). Conclusion: The study suggests that there is significant circulation of Flaviviruses in both regions, posing a public health risk, that could potentially contribute to clinical disease. However, seropositivity rates vary for each specific site. Furthermore, there could be a risk of YFV, WNV, and ZIKV transmission in both sites with DENV transmission specifically noted in Nguruman. The study findings inform direct cost-effective actions (such as YF vaccines) and precise surveillance data of vector populations for improved disease risk prediction. [ABSTRACT FROM AUTHOR]

Background: Peste des petits ruminant (PPR) is a contagious disease caused by the peste des petits ruminants virus (PPRV). The disease poses a significant economic threat to small ruminant production in Ethiopia, particularly to the striving pastoral production system. A cross-sectional study was conducted to estimate the seroprevalence and associated risk factors of PPR in the small ruminants of the Borena Zone. A total of 384 serum samples were collected randomly from sheep and goats and examined for the presence of PPRV antibodies using competition enzyme-linked immune sorbent assay (c-ELISA). Additionally, a retrospective analysis of five years of outbreak data was performed to provide insight into the spatial and temporal distribution of the disease. Results: The seroprevalence of PPRV antibodies in nonvaccinated, vaccinated, and unknown vaccination status of small ruminants in this study was found to be 32.1%, 68.8%, and 45.5%, respectively. Multivariable logistic analysis revealed a statistically significant association between PPRV seropositivity and several factors, including age, animal origin, flock size, and veterinary services status. A retrospective analysis revealed 53 PPR outbreaks in the Borena Zone from 2018 to 2022, exacerbated by low vaccination coverage relative to the at-risk animal population. Conclusion: The study revealed significant gaps in current vaccination efforts, with herd immunity levels falling below the FAO-WOAH recommended threshold of 80%. Despite Ethiopia's ambitious goal to eradicate PPR by 2027, the frequent outbreaks and insufficient herd immunity highlight the inadequacy of the existing strategies. To effectively move toward eradication, Ethiopia must align its approach with the global PPR eradication framework, which emphasizes a comprehensive strategy that includes diagnostics, surveillance, prevention, and the establishment of a robust veterinary regulatory system, rather than relying solely on vaccination. Overcoming logistical challenges, improving vaccination coverage, and optimizing the timing of vaccination campaigns, especially in hard-to-reach areas, will be crucial for reducing outbreaks and making progress toward eradication. [ABSTRACT FROM AUTHOR]

Background: Understanding the level of exposure to Lassa virus (LASV) in at-risk communities allows for the administration of effective preventive interventions to mitigate epidemics of Lassa fever. We assessed the seroprevalence of LASV antibodies in rural and semiurban communities of two cosmopolitan cities in Nigeria with poorly understood Lassa epidemiology. Methods: A cross-sectional study was conducted in ten communities located in the Abuja Municipal Area Council (AMAC), Abuja, and Ikorodu Local Government Area (LGA), Lagos, from February 2nd to July 5th, 2022. Serum samples collected from participants were analyzed for IgG and IgM antibodies using a ReLASV® Pan-Lassa NP IgG/IgM enzyme-linked immunosorbent assay (ELISA) kit. A questionnaire administered to participants collected self-reported sociodemographic and LASV exposure information. Seroprevalence of LASV IgG/IgM was estimated overall, and by study site. Univariate and multivariate log-binomial models estimated unadjusted and adjusted prevalence ratios (aPRs) and 95% confidence intervals (CI) for site-specific risk factors for LASV seropositivity. Grouped Least Absolute Shrinkage and Selection Operator (LASSO) was used for variable selection for multivariate analysis. Results: A total of 628 participants with serum samples were included in the study. Most participants were female (434, 69%), married (459, 73%), and had a median age of 38 years (interquartile range 28–50). The overall seroprevalence was 27% (171/628), with a prevalence of 33% (126/376) in Abuja and 18% (45/252) in Lagos. Based on site-specific grouped LASSO selection, enrollment in the dry season (vs. wet; aPR, 95% CI: 1.73, 1.33–2.24), reported inconsistent washing of fruits and vegetables (aPR, 95% CI: 1.45, 1.10–1.92), and a positive malaria rapid test (aPR, 95% CI: 1.48, 1.09-2.00) were independently associated with LASV seropositivity in Abuja, whereas, only a self-reported history of rhinorrhea (PR, 95% CI: 2.21, 1.31–3.72) was independently associated with Lassa seropositivity in Lagos. Conclusions: The LASV seroprevalence was comparable to that in other areas in Nigeria. Our findings corroborate those from other studies on the importance of limiting human exposure to rodents and focusing on behavioral factors such as poor hygiene practices to reduce exposure to LASV. [ABSTRACT FROM AUTHOR]

The surveillance and detection of zoonotic pathogens in animals is essential for predicting disease transmission pathways and the risks of spillover, but challenges include the costs, ethics and technical expertise required for vertebrate trapping, serum sampling and antibody or virus screening. Surveillance using haematophagous arthropods as a sampling tool offers a unique opportunity to obtain blood samples from a wide range of vertebrate species, allowing the study of host-mosquito associations, and host exposure to pathogens. We explored vertebrate diversity and potential Ross River virus (RRV) transmission pathways by analysing blood-fed mosquitoes collected in Brisbane, Australia. Host origins were identified using barcode sequencing, and host exposure to RRV was assessed using a modified plaque reduction neutralisation test. In total, 480 blood-fed mosquitoes were collected between February 2021 and May 2022. The host origins of 346 (72%) bloodmeals were identified, with humans (73%) and cattle (9%) comprising the dominant hosts. RRV seroprevalence was high in both vertebrate species with evidence of RRV exposure in 70% (21/30) of cattle and 52% (132/253) of humans. This is a novel, non-invasive method of estimating seroprevalence in vertebrate host populations. Our results highlight the potential of blood-fed mosquitoes to provide species-specific insights into pathogen transmission dynamics. [ABSTRACT FROM AUTHOR]

Brucellosis is an important neglected bacterial zoonotic disease in sub-Saharan Africa, including Somalia. A cross-sectional study was conducted in the Garowe district, Nugal region, Somalia, from May 2022 to January 2023 to estimate the seroprevalence of small ruminant brucellosis and assess owners' knowledge, attitudes, and practices toward brucellosis. A total of 384 sheep and goats were selected using a simple random sampling technique and screened for Brucella antibodies by the Modified Rose Bengal Plate Test, and positive samples were then further confirmed using an indirect enzyme-linked immunosorbent assay. For the questionnaire survey, 384 households were selected randomly, and a structured questionnaire was used to assess owners' knowledge, attitudes, and practices toward brucellosis. The overall brucellosis seroprevalence was 4.7% in small ruminants (95% CI: 2.8-7.3), and the true seroprevalence was calculated as 5.2%. According to the multivariable logistic regression analysis, sex was found to be a potential risk factor for small ruminant brucellosis (P <.05). More specifically, female sheep and goats were 9.13 times (aOR 9.13, 95% CI: 1.18-70.33) more likely to become seropositive than males. The owners' knowledge, attitudes, and practices toward brucellosis were found to be low, and education level was associated with owners' knowledge (χ2 = 16.78; P <.001), attitudes (χ2 = 19.4; P <.001) and practices (χ2 = 34.0; P <.001). There is also a significant association between owner knowledge, attitudes, and practices and seropositivity of brucellosis in sheep and goats. Moderate seroprevalence, together with insufficient knowledge, attitudes, and practices of owners, makes brucellosis a threat to animals and the entire community. Hence, raising community awareness of the disease is essential to reduce the impact on small ruminant productivity and the risks to public health. [ABSTRACT FROM AUTHOR]

Introduction: Exposure rates to Histoplasma species, the causative agent of equine epizootic lymphangitis (EL), are unknown amongst working equids in The Gambia. The primary aims of this study were to estimate anti-Histoplasma antibody seroprevalence in the equid population in rural The Gambia and to explore risk factors for seropositivity. Methods: A nationwide cross-sectional study was conducted (February-July 2022), representing baseline measurements of a longitudinal cohort study. Horses (n = 463) and donkeys (n = 92) without EL signs were recruited in 18 study sites. Following informed owner consent, equid clinical and management data were recorded. Blood samples were collected by jugular venepuncture, and sera were subject to the IMMY Latex Agglutination Histoplasma test (LAT). Seropositivity risk factors were explored by multi-level, multivariable logistic regression analysis. Study site and household variance were described using a latent-variable approach. Whole blood DNA extractions were subject to nested ITS-PCR to detect Histoplasma capsulatum var. farciminosum (HCF), and agreement with LAT results was measured using Cohen's kappa statistic. Results: Anti-Histoplasma antibody seroprevalence in horses and donkeys was 79.9% [95% confidence interval (CI) 76.0-83.5%] and 46.7% (95% CI 36.3-57.4%), respectively. In horses, two multivariable models explained the maximum amount of data variability. Model 1 demonstrated increased odds of seropositivity in mares [odds ratio (OR) = 2.90 95% CI 1.70-4.95, p < 0.001] and decreased odds in horses <2.5 years (OR = 0.46 95% CI 0.22-0.95, p = 0.04; reference: ≥4.5 years). Model 2 demonstrated increased odds in horses recruited during the rainy season (OR = 2.03 95% CI 1.08-3.84, p = 0.03) and those owned by farmers reporting previous EL in their equids (OR = 1.87 95% CI 1.04-3.37, p = 0.04). Decreased odds were measured in horses <2.5 years (OR = 0.37 95% CI 0.18-0.78, p = 0.01) and horses reported to transport firewood (OR = 0.45 95% CI 0.28-0.74, p = 0.001). On multivariable analysis of donkeys, decreased odds of seropositivity were demonstrated amongst donkeys owned by households which also owned horses (OR = 0.23 95% CI 0.06-0.85, p = 0.03). HCF infection prevalence in horses and donkeys was 22.0% (n = 102/463, 95% CI 18.3-26.1%) and 5.4% (n = 5/92, 95% CI 1.8-12.2%), respectively. No significant agreement was measured between LAT and nested ITS-PCR results (κ < 0.00). Conclusion: High Histoplasma spp. exposure was demonstrated amongst equids in The Gambia. Investigation of risk factors, including equid husbandry and management strategies, as well as geoclimatic variations, is warranted. Outcomes may inform sustainable and equitable EL control strategies in The Gambia and comparable settings worldwide. [ABSTRACT FROM AUTHOR]

During the COVID-19 pandemic, nonpharmaceutical interventions (NPIs) were introduced to reduce the spread of SARS-CoV-2. This also resulted in a reduction of notifications of other acute respiratory infections and an altered seasonality when NPIs were lifted. Without circulation of pathogens, waning of antibodies is expected, which is a first indicator of decreased immunity. Here, by performing a systematic literature review, we investigated whether reduced antibody levels due to waning immunity contributed to the altered seasonality after NPIs were lifted. Thirteen articles met the inclusion criteria and reported antibody levels or seroprevalence of human respiratory syncytial virus, seasonal human coronavirus, Bordetella pertussis , and influenza virus. We show that the COVID-19 pandemic most likely led to waning of pathogen-specific antibodies, with the strongest evidence for human respiratory syncytial virus and seasonal human coronavirus and with a larger decrease in children vs adults. Waning antibodies might have resulted in out-of-season activity for these pathogens. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii is the common cause of toxoplasmosis in both humans and animals. Sheep toxoplasmosis represents an important role in public health, causing reproductive and economic losses due to abortion and neonatal mortality worldwide. The seroprevalence and molecular detection of sheep toxoplasmosis in Diyala province, Iraq, were the aim of this study. One hundred male slaughterhouses sheep and 100 grassing dairy ewes were examined and divided into groups according to age, season, breed, importation, contact with cats, pregnancy status and abortion. Toxoplasma gondii infection was investigated using a Toxoplasma rapid test and polymerase chain reaction (PCR) test. The overall seroprevalence of toxoplasmosis in rams was 18%, while it was 14% in grassing dairy ewes. The PCR test confirmed the seropositive infection in 50% and 35.7% of rams and diary ewes, respectively. Adult dairy ewes and sheep from slaughterhouses had a statistically insignificantly greater seroprevalence of toxoplasmosis than juveniles. The prevalence of the disease was slightly higher in the winter groups in either rams or diary ewes. Sheep imported from Syria and Iran had twice as high an infection rate as native sheep from Iraq. The infection rate among dairy ewes from the Karadi and Hamdani breeds was not considerably greater than those of other breeds. Sheep with a history of abortion showed higher seroprevalence, and also toxoplasmosis was more prevalent in previously integrated sheep with cats. Therefore, continuous surveillance of sheep toxoplasmosis detection is highly recommended for further prevention. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Neonatal herpes simplex virus (HSV) infection is generally infrequent, despite being a life-threatening illness. Knowledge of its prevalence is limited in Malaysia since most cases are asymptomatic infections and only limited routine neonatal HSV screening is conducted. This study therefore provides a comprehensive investigation of the seroprevalence of HSV-1 and HSV-2 in neonates. MATERIALS AND METHODS: Serological screening for HSV-1 IgG and HSV-2 IgG antibody tests using the Electrochemiluminescence assay was performed on serum samples of 215 neonates delivered from January until December 2022 at Hospital Universiti Sains Malaysia. RESULTS: Of the neonates, 54.4% were found to be HSV-1 positive, while 4.2% were HSV-2 positive. All the HSV-2 neonates were co-infected with HSV-1. Newborns aged 0-10 days were the most infected group by HSV-1 (92.3%) and HSV-2 (55.6%). The most reported clinical presentation was small gestational age (SGA) (60%). Microcephaly and macrocephaly were observed in one neonate each. The clinical presentations of reactive HSV-1 and HSV-2 cases revealed the presence of fever with rash in both cases. CONCLUSION: The high seroprevalence of HSV-1 is alarming. It is hoped that these data will support the advocacy of screening women for HSV before or during pregnancy as a precautionary approach to reducing the risk of vertical transmission. [ABSTRACT FROM AUTHOR]

Adeno-associated viruses (AAV) are widely used as delivery vectors in clinical trials for in vivo gene therapy due to their unique features. Göttingen minipigs are a well-established animal model for several diseases and can be used for the efficacy and safety testing of AAV-based gene therapy. Pre-existing antibodies against AAV may influence the results of testing and, therefore, the animals should be tested for the presence of antibodies against relevant AAV serotypes. The detection of AAVs in pigs may be also important for the virus safety of xenotransplantation. In this study, we screened Göttingen minipigs from Ellegaard Göttingen Minipigs A/S, Denmark, and Marshall BioResources, USA, for antibodies against AAV1, AAV2, AAV6, AAV9 serotypes. Of the 20 animals tested, 18 had no neutralizing antibodies for all AAVs tested, none had antibodies against AAV9, only one had antibodies against AAV6, and the titers of antibodies against AAV1 and AAV2 were less than 1:100, with two exceptions. For total binding IgG, more individuals showed positivity for all the tested serotypes but, in general, the levels were low or zero. Three animals had no antibodies at all against the AAVs tested. Therefore, Göttingen minipigs could be considered an attractive animal model for gene therapy studies. Since some animals were negative for all AAVs tested, these may be selected and used as donor animals for xenotransplantation. [ABSTRACT FROM AUTHOR]

Seroconversion surveys of anti-SARS-CoV-2 antibodies provide accurate estimates of the prevalence of SARS-CoV-2 infections. This nationwide population-based cross-sectional serosurvey aimed to evaluate the prevalence of SARS-CoV-2 antibodies among residents in Gabon and compare the estimated cumulative number of COVID-19 cases with the officially registered number of laboratory-confirmed cases up to December 2021. Households in each province were randomly selected. Twenty-eight localities, including sixteen urban and twelve rural, were randomly selected for the study. Whole blood samples were collected in dry tubes from all study participants nationwide within 15 days. Serum samples were used to measure SARS-CoV-2-specific ELISA titers. Overall, data from 1672 households were analyzed. Out of the 3659 participants, 3175 were found to be positive for SARS-CoV-2 antibodies, resulting in a crude seroprevalence of 86.77%. Stratification of study participants by age group showed the highest seroprevalences in the 20–29 and 40–49 age groups with 91.78% (95% CI: 89.5–93.6) and 91.42% (95% CI: 88.7–93.5), respectively. Nyanga province had the lowest prevalence (72.8%), and Estuaire and Ogooué-Lolo provinces had the highest prevalence (90 and 92%). Our results suggest a high transmission rate in the Gabonese population 21 months after the first SARS-CoV-2 case in the country. This high seroprevalence estimate could indicate that the population may not have adequately implemented or appropriately adhered to the applied infection control measures. [ABSTRACT FROM AUTHOR]

This study analyzes immune responses to SARS-CoV-2 vaccination and infection, including asymptomatic cases, focusing on infection risks during the Omicron wave, particularly among high-risk healthcare workers. In the KoCo-Impf study, we monitored 6088 vaccinated participants in Munich aged 18 and above. From 13 May to 31 July 2022, 2351 participants were follow-uped. Logistic regression models evaluated primary, secondary, and breakthrough infections (BTIs). Roche Elecsys® Anti-SARS-CoV-2 assays detected prior infections (via anti-Nucleocapsid antibodies) and assessed vaccination/infection impact (via anti-Spike antibodies) using dried blood spots. Our findings revealed an anti-Nucleocapsid seroprevalence of 44.1%. BTIs occurred in 38.8% of participants, with reinfections in 48.0%. Follow-up participation was inversely associated with current smoking and non-vaccination, while significantly increasing with age and receipt of three vaccine doses. Larger household sizes and younger age increased infection risks, whereas multiple vaccinations and older age reduced them. Household size and specific institutional subgroups were risk factors for BTIs. The anti-Nucleocapsid value prior to the second infection was significantly associated with reinfection risk. Institutional subgroups influenced all models, underscoring the importance of tailored outbreak responses. The KoCo-Impf study underscores the importance of vaccination, demographic factors, and institutional settings in understanding SARS-CoV-2 infection risks during the Omicron wave. [ABSTRACT FROM AUTHOR]

Simple Summary: Each year, influenza infects millions of people, wildlife, and livestock, resulting in more than 30,000 deaths and a cost of more than USD 1 billion annually in the United States alone. In between the human flu seasons, the virus is maintained in wild bird populations, especially shorebirds and waterfowl. Much of the previous research has focused on ducks' role in this disease cycle; however, there is a growing realization that gulls may provide critical links across space due to their long annual migrations. Yet, little is known of how influenza circulates in gulls. In this work, we evaluate the prevalence of influenza in two species of gulls in Minnesota, USA. We found important differences between species and gull age classes, highlighting the variability in disease spread through wildlife populations, with consequences for how and when the virus might be transmitted to humans/livestock. Importantly, we consider not only ongoing infections, but also look for antibodies that indicate past infections, and which may provide some level of future protection from disease. We find this additional level of surveillance to be beneficial in understanding the spread of disease, especially when researchers are trying to make the most of limited sampling. Influenza A virus (IAV) is a multi-host pathogen maintained in water birds and capable of spillover into humans, wildlife, and livestock. Prior research has focused on dabbling ducks as a known IAV reservoir species, yet our understanding of influenza dynamics in other water birds, including gulls, is lacking. Here, we quantify morphological and environmental drivers of serological (antibody detection by ELISA) and virological (viral RNA detection by PCR) prevalence in two gull species: ring-billed (Larus delawarensis) and Franklin's (Leucophaeus pipixcan) gulls. Across 12 months and 10 locations, we tested over 1500 gulls for influenza viral RNA, and additionally tested antibody levels in nearly 1000 of these. We find substantial virus prevalence and a large, nonoverlapping seroprevalence, with significant differences across age and species classifications. The body condition index had minimal explanatory power to predict (sero)positivity, and the effect of the surrounding environment was idiosyncratic. Our results hint at a nontrivial relationship between virus and seropositivity, highlighting serological surveillance as a valuable counterpoint to PCR. By providing indication of both past infections and susceptibility to future infections, serosurveillance can help inform the distribution of limited resources to maximize surveillance effectiveness for a disease of high human, wildlife, and livestock concern. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has disproportionately affected workers in certain industries and occupations, and the workplace can be a high-risk setting for SARS-CoV-2 transmission. In this study, we measured SARS-CoV-2 antibody prevalence and identified work-related risk factors in a population primarily working at industrial livestock operations. We used a multiplex salivary SARS-CoV-2 IgG assay to determine infection-induced antibody prevalence among 236 adult (≥18 yr) North Carolina residents between February 2021 and August 2022. We used the National Institute for Occupational Safety and Health Industry and Occupation Computerized Coding System (NIOCCS) to classify employed participants' industry. Most participants (55%, 95% confidence interval [CI] 49% to 62%) were infection-induced IgG positive, including 71% (95% CI 60% to 83%) of animal slaughtering and processing industry workers, 1.5 to 4.3 times North Carolina general population infection-induced seroprevalence estimates during overlapping time periods. Considering self-reported diagnostic test positivity and vaccination history in addition to antibodies, the proportion of participants with evidence of prior infection increased slightly to 61% (95% CI 55% to 67%), including 75% (95% CI 64% to 87%) of animal slaughtering and processing workers. Participants with more than 1000 compared to 10 or fewer coworkers at their jobsite had higher odds of prior infection (adjusted odds ratio 4.5, 95% CI 1.0 to 21.0). This study contributes evidence of the severe and disproportionate impacts of COVID-19 on animal slaughtering and processing workers and workers in large congregate settings. [ABSTRACT FROM AUTHOR]

Habitat degradation can increase zoonotic disease risks by altering infection dynamics in wildlife and increasing wildlife–human interactions. Bats are an important taxonomic group to consider these effects, because they harbour many relevant zoonotic viruses and have species‐ and context‐dependent responses to degradation that could affect zoonotic virus dynamics. Yet our understanding of the associations between habitat degradation and bat virus prevalence and seroprevalence are limited to a small number of studies, which often differ in the bats or viruses sampled, the study region, and methodology. To develop a broad understanding of the associations between bat viruses and habitat degradation, we conducted an initial phylogenetic meta‐analysis that combines published prevalence and seroprevalence ('(sero)prevalence') with remote‐sensing habitat degradation data. Our dataset includes 588 unique records of (sero)prevalence across 16 studies, 64 bat species, and five virus families. We quantified the overall strength and direction of the relationship between habitat degradation and bat virus outcomes and tested how this relationship is moderated by the time between habitat degradation and bat sampling and by ecological traits of bat hosts while controlling for phylogenetic non‐independence among bat species. We found no effect of degradation on prevalence overall, although a weak effect may exist when forest loss occurs the year prior to bat sampling. In contrast, we detected a negative but weak association between degradation and seroprevalence overall that was strengthened when forest loss occurred the year prior to bat sampling. No bat traits that we investigated interacted with habitat degradation to impact virus outcomes, suggesting observed trends are independent of these traits. Biases in our initial dataset highlight opportunities for future work; prevalence was highly zero‐inflated, and seroprevalence was dominated by Desmodus rotundus and rabies virus. These findings and subsequent analyses will improve our understanding of how global change affects host–pathogen dynamics. [ABSTRACT FROM AUTHOR]

Background: Toxoplasmosis is one of the most widespread foodborne parasitic zoonoses caused by the obligate intracellular protozoan Toxoplasma gondii. Although a number of studies have reported on the seroprevalence and risk factors of T. gondii infection in ruminants in China, information about T. gondii infection in cattle in Hunan province of China is not available. Material and Methods: Sera of 985 cattle and 1147 goats were examined for the presence of specific antibodies against T. gondii using the indirect hemagglutination test. Some risk factors related to the presence of cats, herd size, gender, age, and geographical origin were determined using a binary logistic regression. Results: Specific IgG against T. gondii were detected in 8.3% (82/985) and 13.3% (153/1147) of the cattle and goats, respectively. Based on statistical analysis, the presence of cats and gender were considered important risk factors for T. gondii infection in cattle and goats in the farms in this study (P < 0.05). Conclusion: Our results provide a baseline for future prevention and control of T. gondii infection in cattle and goats in Hunan province, subtropical China. This is the first report of T. gondii seroprevalence in cattle in Hunan province, China. [ABSTRACT FROM AUTHOR]

Background: Cytomegalovirus (CMV) is the most common congenital infection in pregnancy with potential long-term adverse effects on the fetus. There is limited data on CMV seroprevalence in pregnant women in Singapore, with last reported study dating back over two decades. We look at the latest CMV seroprevalence in antenatal population in Singapore. Methods: Between January 2021 and August 2021, 385 pregnant women receiving antenatal care at Singapore General Hospital were randomly selected for CMV IgG test to be performed on their blood samples collected during the first trimester of their pregnancies. Positivity for CMV IgG represents past exposure prior to pregnancy. Results: Overall CMV seroprevalence was 71.7% (276/385) (95% CI 067, 0.76, p value < 0.001). The trend of CMV IgG positivity increased with age, 68.3% (95% CI 0.60, 0.76, p value < 0.001) in those aged 20–29, 72.5% (95% CI 0.66, 0.78, p value < 0.001) in the 30–39 age group, and 79.0% (95% CI 0.67, 0.76, p value 0.012) in women over 40. Conclusions: There is a declining trend in CMV seroprevalence among pregnant women in Singapore, which indicates that a substantial portion of this population faces the risk of primary maternal CMV infection during pregnancy. Emerging research suggests that prenatal treatment with valacyclovir effectively reduces the likelihood of vertical transmission. Considering this evidence, it is imperative to reevaluate the recommendations for universal maternal CMV screening during pregnancy. [ABSTRACT FROM AUTHOR]

Scaup, including both Lesser and Greater (Aythya affinis and Aythya marila, respectively), are a grouping of populous and widespread North American diving ducks. Few influenza type A viruses (IAV) have been reported from these species despite a high prevalence of antibodies to IAV being reported. Existing virologic and serologic data indicate that IAV infection routinely occurs in scaup, yet it is unknown which IAV subtypes are linked to these infections. In this study, we aimed to gain a more complete picture of IAV natural history in Lesser and Greater Scaup from two coastal flyways in North America in 2015-18 (302 samples from California in the Pacific Flyway and 471 samples from Maryland in the Atlantic Flyway). Low prevalence of active IAV infection was detected by real-time reverse-transcription PCR in Lesser Scaup sampled in Maryland and California (2.8% and 8.1%, respectively). A single IAV (HINI) was isolated in embryonated chicken eggs from a bird sampled in California. Similarly low levels were observed in Greater Scaup in California (3.3%). Antibodies to the nucleoprotein as detected with a commercial blocking ELISA were observed in all species and flyway combinations. Antibody seroprevalence estimates were higher in adult Lesser Scaup than in juveniles at both the <0.5 (P<0.001, z=-3.582) and <0.7 serum-sample-to-negative-control absorbance thresholds (P=0.003, z=-2.996). Neutralizing antibodies to HI-H12, H14, and H15 were detected using a microtiter virus neutralization assay, with the highest prevalence of antibodies against H1 (38%), H6 (36%), and H11 (35%). The high prevalence of antibodies to IAV and evidence of previous exposure to numerous subtypes are consistent with a high level of population immunity and a low prevalence of infection. These results must be interpreted in the context of season (winter sampling), as results may vary with the annual influx of naïve juvenile birds. [ABSTRACT FROM AUTHOR]

Background: In Algeria, data on the epidemiology of theileriosis in small ruminants are limited. Objectives: The current study investigates the seroprevalence of Theileria spp. in goats from the M'Sila region, Central Algeria. Methods: Blood samples of 128 goats from 19 farms were collected from the locality of Maâdid. The indirect fluorescence antibody test (IFAT) was performed to test the goats' sera for antibodies against Theileria ovis and Theileria lestoquardi. Results: Out of 128 tested samples, 21 sera (16.40%) were positive for T. ovis antibodies. All samples were seronegative for T. lestoquardi. The seroprevalence of T. ovis varied from 10% to 30% on farms. The seropositivity rates did not differ significantly with age, sex, or breeding system of goats. Tick-infested goats were significantly more seropositive than no-infested goats. Conclusion: The present study reports essential data on the epidemiology of caprine theileriosis from Central Algeria. [ABSTRACT FROM AUTHOR]

To clarify the epidemiology of enterovirus D68 (EV‐D68), an enterovirus rarely identified in the 20th century, we performed seroepidemiological analysis against EV‐D68 using sera collected in 1976, 1985, 1990, 1999, 2009, and 2019, as well as Yamagata isolate (EVD68/Yamagata.JPN/2023‐89), in Yamagata, Japan. The neutralizing antibody (Ab)‐positive rates for those under 20 years old were 61.0%, 82.5%, 84.3%, 46.7%, 50.5%, and 67.9%, in each year, whereas the rates for those above 20 years old were between 93.4% and 99.1%. Generally, geometric mean titers (GMTs）increased with age among children and the total GMT in each year was 25.4, 49.2, 37.2, 30.8, 29.5, and 33.9, from 1976 to 2019, respectively. The findings in this Yamagata‐based study showed that the seroprevalence of EV‐D68 over the last four decades has increased with age among children, as a susceptible group, and then reaches a plateau of over approximately 80% among adults. This study clearly revealed that EV‐D68 was stably transmitted among children in the 20th century, when EV‐D68 detection was quite rare. [ABSTRACT FROM AUTHOR]

Leptospirosis is a worldwide re-emerging zoonotic disease. The study was conducted to estimate the Seroprevalence of canine leptospirosis in a total of 450 dogs, from a total of 97 puppies and 353 adult dogs selected for examination Sampling, started from January to December 2023 in District Kasur in the province Punjab of the country Pakistan. Leptospira IgG ELISA kit manufactured by DRG Instruments GmbH, Germany was used for the screening of canine Leptospira antibodies. Out of 450 tested dogs, 183 dogs (40.67%) were tested positive for Leptospira antibody for the screening of Leptospira antibodies. The estimated Seroprevalence of leptospirosis in various age groups of dogs, were 23.7% (23/97) and 45.3% (160/353), in puppies and adults, respectively (P < 0.05). It was found that out of the sampled dogs, a total of 35/127 (27.6%), 29/100 (29%), 73/130 (56.2%), and 46/93 (49.5%) dogs were tested seropositive for Leptospira antibodies in winter, spring, summer and fall, respectively (P < 0.05). [ABSTRACT FROM AUTHOR]

Hepatitis E virus (HEV), species Paslahepevirus balayani, poses a global public health threat, especially in developing countries, by causing acute enterically transmitted hepatitis. HEV infects various mammalian hosts and belongs to the genus Paslahepevirus in the family Hepeviridae. While swine are recognized as the main hosts of HEV, rabbits, which can also be affected by swine HEV-3 related strains, serve as the primary reservoir for the distinct emerging and zoonotic HEV-3ra subtype. In Portugal, where the European wild rabbit is abundant, their role in HEV epidemiology remains unclear. The primary aim of the present research was to evaluate the circulation and the potential for HEV infection within these species. This study employed a molecular and longitudinal serological approach to investigate HEV in Portuguese rabbits. Among the 205 wild rabbits tested, a seroprevalence of 2.44% (95% CI: 0.80–5.60) was found, with no significant associations with age, sex, localization, or sampling dates. Seropositive animals were found in the south and center regions of the country. HEV RNA was not detected in 120 fecal samples, suggesting a natural, low level, and widespread viral circulation. The study underscores the need for further research to comprehend HEV dynamics in these species, which is crucial for assessing potential transmission risks to humans. [ABSTRACT FROM AUTHOR]

Lumpy skin disease (LSD) is an infectious disease of cattle caused by lumpy skin disease virus (LSDV), which is a member of the Poxviridae family and genus Capripoxvirus. The illness is marked by mild to severe symptoms, including edema, fever, lymphadenitis, widespread skin nodules, and infrequently, death. In spite of its significance, little is now understood about the magnitude and predisposing factors in Tanzania. The aim of this study was to determine the seroprevalence of LSD in cattle within Kilolo district, and to identify key predisposing factors. A cross-sectional study was conducted in 17 villages within Kilolo district from February to March 2024 to estimate the seroprevalence of LSD in cattle. A total number of 276 serum samples was obtained from 65 cattle herds and a Double Antigen ELISA (ID Screen®) (IDVet, France) was used to screen for LSDV antibodies. Logistic regression analysis was employed to assess the risk factors for LSD seropositivity. The overall animal- and herd-level seroprevalence were 18.1% (95% CI: 13.98-23.14) and 44.6% (95% CI: 7.54-15.38), respectively. The highest individual animal level seroprevalence was documented in Irindi village 39.1% (95% CI: 5.36-12.24), followed by Masalali 38.5% (95% CI: 6.25-13.50), Ng'uruhe 37.5% (95% CI: 5.65-12.66), Irole 33% (95% CI: 1.5-6.10), and Utengule 26.5% (95% CI: 3.07-8.81) with significant differences (p=0.003). The seroprevalence of LSD varied significantly (P<0.001) among the three age groups, with adults >2 years having a higher seroprevalence (29.8%, 95%CI, 52.27-64.21) than yearlings aged 1-2 years (5. 6%, 95%CI, 9.31-17.60) and calves (0.0%, 95%CI, 23.36-34.35). Sex (Female/male, OR=2.0937, 95%CI, 1.4642-3.0248), age (Yearling/Adult, OR=0.1756, 95%CI, 0.0841-0.3730), village (OR=0.8970, 95%CI, 0.8349-0.9636) and herd size (Large/small, OR=1.9464, 95%CI, 1.1597-3.2669) were significant risk factors for LSDV seropositivity in Kilolo district. Raising awareness among livestock owners and veterinary staff about the disease and its risk factors, vaccination and vector control measures should be prioritized to minimize the transmission of the disease. [ABSTRACT FROM AUTHOR]

Poultry farming is crucial for the livelihoods of small-scale producers in the Northen Benin, yet the industry faces challenges from diseases like ND, which threaten both poultry health and economic stability. This study investigates the seroprevalence of Newcastle Disease Virus (NDV) among indigenous chickens and guinea fowl in the Atacora and Donga regions of Northern Benin, addressing a significant gap in regional poultry health data. A cross-sectional study was designed, sampling a total of 300 birds, including 191 indigenous chickens and 109 guinea fowl, from six districts. Systematic random sampling was employed to select smallholder farms, and blood samples were collected for Hemagglutination inhibition (HI) tests to detect NDV antibodies. Statistical analyses, including chisquare tests, determined associations and differences in seroprevalence between regions and species. Results revealed notable variations in NDV seroprevalence between the two regions. In Atacora, 59.22% of chickens tested positive for NDV antibodies, with 52.33% of non-vaccinated and 94.12% of vaccinated chickens showing positive results. In Donga, the overall seroprevalence was 46.59%, with 27.78% of non-vaccinated and 59.62% of vaccinated chickens testing positive. A chi-square test indicated a significant difference in NDV seroprevalence between the two regions for chickens (x2 = 12.901; P = 0.024). For guinea fowls, seroprevalence was 63.53% in Atacora and 62.50% in Donga, with no significant difference observed (x2 = 1.102; P = 0.954). This study provides the first serological data on NDV prevalence in northern Benin, highlighting the endemic nature of NDV and the critical epidemiological role of guinea fowls due to frequent exposure and field infections, especially in the Atacora region. It recommends enhancing vaccination coverage, improving biosecurity measures, and conducting further research to isolate and characterize virus strains to develop more effective control strategies. [ABSTRACT FROM AUTHOR]

Severe fever with thrombocytopenia syndrome (SFTS), a tick-borne disease caused by Dabie bandavirus (SFTSV) is an emerging infectious disease of substantial concern in East Asia. In 2019, Ongkittikul S et al. reported the first case of SFTS in Thailand. Our report describes a One Health investigation of SFTS zoonosis examining the index case and suspected animal reservoirs using real-time RT-PCR and immunoassays. We add to the report on the first confirmed case of SFTSV infection in a human in Thailand by conducting a limited but informative One Health surveillance study. Dogs and cats tested positive for SFTSV antibody using IgG ELISA. We conclude that domestic dogs and cats might serve as potential reservoirs for SFTSV spread due to their closer proximity to the index case than other non-domestic animals. Notably, we did not detect SFTSV in synanthropic cats or dogs—nor did we detect SFTSV in Rhipicephalus sanguineus ticks—using RT-PCR. We propose that One Health investigations coupling genomic and serologic assays in response to new SFTS cases could play a pivotal role in preventing and managing SFTS among humans and animals in East Asia. As such, we are establishing a collaborative response to SFTS in Thailand through human outbreak investigations that align with principles of One Health, through environmental surveys and animal RT-PCR and immunoassays. Our investigation highlights the importance of coupling RT-PCR with seroprevalence assays as principal elements of One Health surveillance for SFTS in order to shed light on potential animal reservoirs and track emerging zoonosis. [ABSTRACT FROM AUTHOR]