Ticks and Tick-borne Diseases

Zoos may serve as sentinel sites for zoonotic vector-borne diseases. West Nile virus (WNV) and Usutu virus (USUV) are closely related orthoflaviviruses transmitted between Culex mosquitoes and a bird reservoir. Both viruses can also infect mammals, including humans, where they may cause symptoms and, more rarely, hospitalization and death. However, serological cross-reactivity between WNV and USUV complicates their differential diagnosis. Here, we aimed to reconstruct the dynamics of emergence of WNV in a zoo located in a newly affected area in Europe, using ELISA and Virus Neutralization Test (VNT) serological analysis of 1707 animal sera collected between 2015 and 2024. Combining this data in a model accounting for cross-reactivity with USUV, we estimated yearly forces of infection (FOI) by both viruses, and thus found that WNV likely circulated in the area one year prior to the first cases reported to the passive surveillance system. Our results also showed that, in the zoo, mammals and reptiles had a lower risk of infection than birds (relative risk of 0.14 [0.05; 0.28]), and that the exposure of birds to water (aquatic lifestyle or proximity to stagnant water) affected the risk. Finally, we estimated diagnosis parameters, including the sensitivity of the VNT (80.4% [76.5%; 84.3%]), the expected VNT titer value, and the level of serological cross-reactivity between viruses during the VNT. To conclude, our modelling framework allowed to disentangle the co-circulation of two closely related viruses, a crucial point in ensuring the reliable sentinel surveillance of these vector-borne zoonotic pathogens.

Dengue transmission is strongly influenced by climatic conditions that affect mosquito population dynamics and virus circulation. In Southern Brazil, where dengue historically occurred at low levels, recent climatic anomalies may be contributing to the expansion of Aedes vectors and an increase in local dengue incidence. This study investigated the spatiotemporal association between climatic variables, Aedes mosquito infestation and dengue cases in Porto Alegre (Southern Brazil, 2018 to 2025). Entomological, surveillance and climatic data were analyzed using Morans I and LISA for spatial association, Kendall correlation, polynomial regression and LASSO to identify relevant drivers and develop predictive models of mosquito infestation and dengue incidence. A strong spatial association between Aedes aegypti and Aedes albopictus was observed, with persistent local clusters detected across all years. Annual climatic variables were associated with mosquito abundance in several districts. Overall, rainfall frequency had a stronger effect on Aedes aegypti abundance than accumulated rainfall. Temperature and lagged infestation indices showed strong association with both species and dengue incidence, with effects observed up to four weeks prior. Predictive models demonstrated good agreement between observed and predicted values, particularly within low to moderate infestation levels. Lagged variables were consistently retained in both mosquito infestation abundance and dengue incidence models, highlighting the importance of temporal predictors for anticipating vector dynamics and dengue risk. This approach is generally applicable for predicting Aedes infestation and disease incidence and emphasizes the importance of integrating entomological and climatic surveillance data to improve anticipation and detection of dengue risk periods and support more effective public health interventions.

Chronic Wasting Disease (CWD) is a transmissible spongiform encephalopathy (TSE) of cervids (elk, deer, moose, and reindeer) that is increasing in prevalence and expanding to new geographical areas. TSEs, commonly referred to as prion diseases, are fatal neurodegenerative diseases that occur in a variety of mammals, including humans, and typically exhibit species-specific characteristics. This study reports the sequencing of the prion protein gene (PRNP) in retropharyngeal lymph node samples from 358 Montana mule deer (Odocoileus hemionus) and the identification of 36 PRNP genetic variants, many of which have not been reported previously. Further investigations tracked spatiotemporal characteristics of variants to hunting districts, year of harvest, and CWD status. PRNP polymorphisms V12F, D20G, R40Q, and S225F were examined with EmCAST computational predictions to determine the relationship between sequence and structural variations providing further insights into mechanisms affecting CWD outcomes. EmCAST predictions suggest the novel variant V12F phenotype is attributable to functional changes such as altered protein-protein interactions that might be linked to the CWD positive status of the samples. Notably, the analysis of S225F by EmCAST predicted that S225F is a neutral mutation for folded PrP and incompatible with fibril PrP, suggesting a potential structural mechanism for why this previously known variant may provide protection against CWD based on reduced fibril PrP formation. The CWD-positive samples harboring PRNP variants were examined with the prion RT-QuIC assay, including the novel variant V12F, which resulted in prion seeding activity. Author SummaryChronic Wasting Disease (CWD) is a fatal disease of cervids, which include deer, elk, and moose. Since its discovery in 1967, CWD has spread to 36 U.S. states and four Canadian provinces, with prevalences exceeding 20% in select free-ranging populations. With the popularity of hunting big game animals and the role of these species in the ecosystem, concerns have arisen regarding the transmission of disease to humans, as well as how to mitigate long term consequences of disease on animal populations. Given the significant risk of species spillover and the limitations of current management, innovative genetic research is essential. Our study identified novel PRNP genetic variants in Montana mule deer, cataloging their regional distribution and CWD status across several hunting seasons. By investigating the impact of these polymorphisms on protein stability and seeding activity, we provide critical insights into the genetic factors that influence disease phenotypes and transmissibility in wild cervid populations.

Background Venezuelan haemorrhagic fever (VHF), caused by Guanarito virus (GTOV), is a zoonotic disease endemic to the western plains of Venezuela. Despite decades of recognition, its epidemiology and clinical profile remain poorly characterised. Methodology We analysed individual level data from standardised case report forms submitted to the Venezuelan National Epidemiological Surveillance System between 2017 and 2024 for suspected VHF cases in Barinas, Apure, and Portuguesa. Demographic, clinical, and laboratory variables were examined to characterise temporal and geographical patterns and to define the clinical profile of VHF compared with endemic arboviral infections. Principal Findings Among 480 suspected cases, 72 (15.0%) were laboratory confirmed GTOV infections. Confirmed cases occurred predominantly in men engaged in agricultural or service related occupations, with the highest prevalence among individuals aged 46 to 90 years. A marked seasonal pattern was observed, with most cases occurring between September and January. The most frequently reported symptoms included headache, haemorrhage, sore throat, and diarrhoea. Compared with other endemic arboviral infections, GTOV was more strongly associated with headache, myalgia, sore throat, haemorrhage, and abdominal pain, delineating a distinct clinical phenotype relative to diseases caused by encephalitic alphaviruses, chikungunya virus, dengue virus, and Zika virus. The case fatality ratio among laboratory confirmed cases was 36.1% (95% CI: 25.1 to 48.3). GTOV infection was independently associated with mortality (adjusted relative risk [aRR] 3.66; 95% CI 2.28 to 5.87; p < 0.001), underscoring its substantial clinical severity. Conclusion GTOV remains endemically transmitted in western Venezuela, disproportionately affecting older men engaged in agricultural and service related occupations. Its seasonality and clinical phenotype, characterised by haemorrhage, sore throat, and gastrointestinal symptoms, highlight the need for clinical awareness and improved differential diagnosis, particularly in remote endemic settings with limited access to laboratory testing.

BackgroundOnchocerciasis remains a public-health challenge in the Democratic Republic of the Congo (DRC). The Kakoi-Koda focus, Ituri Province, exhibited high endemicity in the early 2000s and received community-directed treatment with ivermectin (CDTI) in some health zones (e.g., Nyarambe), but not in others (e.g., Logo). Moxidectin clinical trials were conducted in these health zones, alongside onchocerciasis-associated epilepsy studies. MethodologyWe synthesised epidemiological (including nodule prevalence), entomological and CDTI programmatic data. We collated anti-Ov16 serological data from epilepsy-related studies (community, cohort, case-control designs, 2015-2021) and skin-snip microscopy results from two moxidectin trial screenings (2009-2011; 2021-2023) and epilepsy-related studies (2015-2017). Geospatial analyses were used to describe land-cover change relevant to vector ecology and to identify areas with recent transmission. Principal findingsOnchocerca volvulus transmission declined markedly over time. In CDTI-naive Logo villages, microfilarial prevalence fell from 69-79% (first trial, 2009-2011) to 9% (second trial, 2021-2023), and mean infection intensity from 17-26 to 1 microfilariae per skin snip, similar to declines observed in Nyarambe villages under CDTI (72% to 3% and 11 to 0.4, respectively). Anti-Ov16 seroprevalence among children aged 3-10 years was low (0-5%) from 2016 onwards, and seropositivity was geographically circumscribed, mirroring contemporary skin-snip results. Human landing catches and breeding-site prospections (2015-2017) identified Simulium dentulosum and S. vorax as the current anthropophagic species, with no evidence of S. neavei after 2009. Progressive deforestation and canopy opening provide a plausible mechanism for a shift from crab-associated S. neavei habitats towards more open-habitat vectors. SignificanceConsistent parasitological, serological, entomological and geospatial evidence indicates substantially reduced transmission across Kakoi-Koda, with spatially-circumscribed residual transmission. Whether the current simuliid species can sustain transmission above elimination thresholds remains uncertain. Targeted, integrated surveillance is warranted to guide CDTI and stop-CDTI decisions. The dataset assembled here can be used to inform transmission modelling of these dynamics. Author SummaryOnchocerciasis, also known as river blindness, is a parasitic disease of public health concern in sub-Saharan Africa, transmitted by blackfly vectors. The disease is responsible for skin and eye clinical manifestations and is associated with neurological complications. We investigated an area in north-eastern Democratic Republic of the Congo called the Kakoi-Koda onchocerciasis focus, where the infection was once common. We reviewed and assembled data from past studies on infection in humans and blackflies, and analysed satellite imagery to assess the loss of tree cover that can affect where blackflies live and breed. We found that the prevalence of onchocerciasis in Kakoi-Koda has declined markedly in recent years. This decline appears linked to the disappearance (by deforestation) of the habitat suitable for some blackfly species, and to ivermectin distribution to treat onchocerciasis in parts of the focus. Our findings help to understand why onchocerciasis has decreased across the Kakoi-Koda focus and highlight a small number of fast-flowing river segments where other blackfly species may allow small pockets of local transmission. These results support continued, targeted monitoring to determine whether the disease is still transmitted in specific locations where elimination interventions may be needed.

Borealpox virus (BRPV; formerly Alaskapox) is an orthopoxvirus that has caused seven reported human infections in Alaska since 2015, including a fatal case in 2023. The natural reservoir of BRPV is unknown, although previous investigations have raised the possibility of wild small mammals transmitting the virus to humans, either through direct contact or via domestic cats and dogs. To understand which species may be involved in the maintenance and/or spillover of BRPV in Alaska, we trapped and sampled wild small mammals (including voles, shrews, and squirrels) in 2021 and 2024 near reported human case locations in Fairbanks and the Kenai Peninsula, respectively. We found evidence of previous exposure to orthopoxviruses in five species (including the House Mouse, Mus musculus) and detected BRPV DNA as well as viable virus in Northern Red-backed Voles (Clethrionomys rutilus). Further, screening of tissues from historical museum specimens revealed BRPV DNA in C. rutilus specimens collected in Denali National Park and Preserve in 1998 and 1999, 17 years before the first reported human case of BRPV. Phylogenomic analysis of all human and animal BRPV isolates strongly supports the hypothesis of local human infections through multiple spillover events. These findings suggest C. rutilus as a possible reservoir species for BRPV and indicate that BRPV has been present in Alaskan wild small-mammal populations for at least 25 years. Our study highlights the potential of museum collections to elucidate the temporal, spatial, and host ranges of emerging pathogens. Further museum- and field-based sampling will clarify the true geographic range of BRPV, which is closely related to Old World orthopoxviruses and may be circulating beyond North America.

The early evolutionary history of modern domestic horses (Equus caballus/E. ferus caballus), known as the DOM2 lineage, is well documented due to numerous archaeological and ancient DNA (aDNA) studies. Although many uncertainties remain in the domestication timeline, current evidence suggests that the domestication of modern horses began in the Pontic-Caspian steppe at least [~]2700 BCE (before common era), or even earlier. However, it is not known how long remnant wild horse populations survived or when domestic horses were introduced into Northern Europe. In this study, we review the current knowledge of horse domestication, focusing on Northern Europe. We analysed prehistoric horses from western Russia to assess the body sizes of wild horses from the Ivanovskaya site (5900-3800 BCE) in the Pontic-Caspian steppe, and the body weight of one Lithuanian wild horse (4000-3800 BCE). Additionally, we analysed body sizes of Late Bronze Age-Early Roman Age horses (1100 BCE-300 CE; common era) and re-analysed body sizes and estimated rider weights of historic domestic horses from Lithuania (100-1400 CE). We searched for pathological changes and signs of bit wear indicative of bridling. Furthermore, we investigated maternal genetic diversity by sequencing ancient mitochondrial DNA. We found that wild horses from Ivanovskaya were intermediate in body size between earlier and more recent horses of the Eurasian Steppe, and that the Lithuanian wild horse weighed only [~]270 kg and Late Bronze Age-Early Roman Age horses 200-300 kg. Lithuanian domestic horses were pony-sized (< 130 cm on average). Bit wear was confirmed on one tooth, the oldest domestic horse in Lithuania (799-570 cal BCE). Another tooth showed signs of the Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) condition. Mitochondrial DNA was successfully amplified from one Ivanovskaya wild horse along with 25 other ancient samples, including Lithuanias oldest domestic horse. mtDNA diversity was high, revealing several maternal lineages.

RNA viruses are common in tephritid fruit flies including the Queensland fruit fly, Australias most significant horticultural pest. For many their transmission, tissue tropism and load across host development remain unexplored. Yet these factors are important for host biology, ecology and pest management. We investigated Bactrocera tryoni orbivirus (OV), Bactrocera tryoni xinmovirus (XV), Bactrocera tryoni toti-like virus (TLV) and Bactrocera tryoni iflavirus species 2 (IVsp.2) that commonly coinfect B. tryoni laboratory populations. OV and XV transmission was vertical within and on eggs, while TLV transmission was vertical within eggs. IVsp.2 was not detected in eggs but was present in adults; however, IVsp.2 was horizontally transmitted, with viral load increasing with cohabitation time with infected flies. Horizontal transmission was not observed for the other viruses. OV had a similar load across all tissues, while XV was consistently more abundant in ovaries. TLV had a high viral load in the brain whereas IVsp.2 was abundant in the thorax, foregut and midgut. Besides differences in eggs, the viruses were detected in all other developmental stages, but viral load patterns differed: viral load remained constant for TLV, fluctuated for OV and XV, and was low in pre-adult stages and high in adults for IVsp.2. Our findings demonstrate distinct transmission strategies and tissue tropism among the viruses, providing new insights into their epidemiology and role in host biology. Furthermore, contrary to prevailing views that viruses are generally horizontally transmitted, most known RNA viruses of B. tryoni are vertically transmitted affecting the evolution of host-virus interactions.

IntroductionIncreasing occurrence of epidemics and pandemics and concurrent emergence of different pathogens calls for multi-sectoral, multi-pathogen preparedness actions. Data on various factors that drive emergence of diverse pathogens can inform evidence-based preparedness by identifying geographies at-risk. When leveraging evidence within a One Health approach, multiple pathogens can be addressed simultaneously, thereby strengthening countries pandemic preparedness efforts. MethodsFor seventeen priority pathogens (avian influenza viruses, zoonotic coronaviruses including COVID-19, hemorrhagic fever viruses including Ebola, Henipaviruses, and arboviruses including yellow fever and Zika), we identified global evidence on animal reservoirs, vectors, environmental suitability, and reported human cases. We discriminated geospatially recorded pathogen detections from a background sample and constructed maps using these datasets to generate an evidence-based assessment of emergence risk globally. ResultsSeventeen pathogen-specific assessments were combined into a global composite map. Sub-Saharan Africa and South Asia have evidence supporting emergence risk for the greatest number of pathogens (included areas at-risk of all pathogens) and scored highest when strength-of-evidence weightings were factored. The Americas had the lowest tally of considered pathogens. Environmental suitability analyses received the highest weights, reservoir ranges the lowest. DiscussionPreparedness and readiness must consider the range of global biological threats. Our methodology is capable of incorporating changing evidence on emergence potential for multiple pathogens to identify geographies at higher risk with different pathogen combinations. Our maps can contribute to existing decision-support structures, guiding shared interventions and strategic allocation of resources for spillover prevention and pandemic preparedness, thereby enhancing local response capacities applying a multidisciplinary approach. Research in ContextO_ST_ABSEvidence before this studyC_ST_ABSUsing PubMed, we searched for "[PATHOGEN] Preparedness Map" for each of seventeen priority pathogens to explore what resources might exist to be used to guide contemporary preparedness actions. The seventeen pathogens were: avian influenza viruses (AIV,all subtypes), chikungunya virus (CHIKV), Crimean-Congo hemorrhagic fever virus (CCHF), dengue virus (DENV), Ebola virus (EBV), Hendra virus, non-specific Henipaviruses, Lassa virus (LASV), Marburg virus (MARV), Middle East respiratory syndrome coronavirus (MERS-CoV), monkeypox virus (MPXV, all clades), Nipah virus, Yersinia pestis, Rift Valley fever virus (RVF), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), yellow fever virus (YFV), and Zika virus (ZIKV). We also searched for "Emergence Preparedness Map" to try and identify a singular resource that housed all these pathogens. Searching for specific pathogens identified resources that had deployed specific approaches or types of data in answering this question, but often did not collate multiple varied evidence streams. Similarly, the more detailed resources tended to be more geographically restricted in scope. When searching for emergence resources more broadly, we identified some clusters of epidemiologically related pathogens being synthesized (for instance thinking about integrated management of vector-borne diseases), but none that spanned the full repertoire of pathogens listed. Others attempted to characterize the phenomena of emergence more broadly, but as a result lost the ability to further capitalize on pathogen-specific activities since pathogens were not a building block within a broader methodology. Added value of this studyIn evaluating the emergence potential for seventeen priority pathogens, we have collated the widest range of pathogens into a common map for synthesis. In doing so, we provide a support mechanism for actionable next steps for epidemic and pandemic preparedness at scale that leverage current knowledge. Contrasting to prior assessments, we leverage different types of data and provide a mechanism to differentially weight their inclusion. We outline a mechanism by which even for pathogens where comprehensive or detailed data is not present, the information currently available can be acknowledged and integrated, to provide immediate support for decision-making, while future enhancements are integrated when available and iterated upon. We also demonstrate how this modular methodology allows customized aggregations of pathogens where scopes of work necessitate - for instance, collating all pathogens with similar vectors where vector control actions can be undertaken. We show with examples of Marburg virus disease in Equatorial Guinea, how the maps demonstrated the prior evidence-base related to emergence of this disease in that geography and use that example to outline how these maps can indicate geographies of concern. Implications of all the available evidenceEpidemic and pandemic preparedness is multi-faceted and multi-sectoral; some actions require pathogen specific insights, while other actions will work to counter a group of pathogens simultaneously. With this methodology, we demonstrate that it is possible to integrate data from diverse formats across different transmission routes and pathogens ecological dynamics globally to produce a set of resources to support local, regional, and global evidence-based decision making. Different groupings can be called upon to support different actions - pathogen specific maps where pathogen-specific vaccination schedules need to be undertaken; tracking the full pathogen-set that any given reservoir is implicated in; determining the differential diagnosis needs for a specific health facility and corresponding population it serves as a function of the implicated local pathogens or their potential future emergence; and supporting local health facilities in developing protocols, training, and necessary equipment to effectively detect and respond to possible local cases. Finally, these maps are designed to evolve alongside advancing infectious disease intelligence, allowing for continuous enhancement and resolution of data limitations across diverse surveillance systems and national contexts.

Deer tick virus (DTV), or lineage II Powassan virus, is an emergent tick-borne encephalitis virus in North America. Survivors frequently sustain neurologic sequelae. Nationally reported cases have been increasing. DTV is thought to be maintained in nature by multiple modes including horizontal transmission (from viremic host to tick), cofeeding transmission (between ticks feeding nearby) and by transovarial transmission (female to progeny). Analysis of the relative importance of each mode has been hindered by low enzootic transmission. In 2021, Marthas Vineyard, Massachusetts experienced an epizootic that allowed us to probe the modes of transmission on the island. We detected virus in 7.8% of questing deer tick nymphs (161 of 2063) and in 0.3% of lone star nymphs (2 of 678). Infected ticks had a highly focal distribution; 56% of infected ticks derived from only 4 of 71 collection sites. Tick mitochondrial genome sequencing demonstrated that infected ticks were not more likely to be siblings than negative ticks and, therefore, were unlikely to have inherited the infection. Whole viral genome sequencing revealed the presence of 3 genotypes, 58% were type1, 0.6% type2, and 13.7% type3. Tick host bloodmeal identification analyses determined that nymphs infected with type1 were significantly associated with having fed on shrews (50 of 94 type1 ticks, odds ratio=2.3, p<0.001). This is consistent with shrews serving as a reservoir. Ticks infected with type3, however, had no host associations, consistent with infection acquired by cofeeding. It may be that local DTV genetic variation is shaped by transmission modes or host associations. ImportanceDeer tick virus (DTV; Powassan lineage II) is a tick-borne encephalitis virus that causes a rare zoonosis in North America. Cases have been increasingly reported within the last decade. Is the recent risk trend due to increased transmission? How this virus is perpetuated in nature is not well understood. We took advantage of a natural epizootic on Marthas Vineyard to probe how the ticks there had become infected. Using a combination of viral whole genome sequencing and bloodmeal remnant identification in ticks, we find that the mode of transmission varied by viral genotype. One genotype is associated with ticks that had fed on shrews, and another did not depend on a specific reservoir host. Host associations may drive genetic diversity of deer tick virus and thus local host population dynamics may influence zoonotic risk.

Due to long co-evolutionary histories, many zoonotic pathogens are thought to exert little or no negative effects on their wildlife reservoir hosts. However, there remains a lack of rigorous investigations in natural settings. We conducted a 3-year factorial field experiment to investigate how survival of the Puumala hantavirus (PUUV) reservoir, the bank vole, is impacted by PUUV infection, nematode infections, and food availability. We hypothesized that PUUV would not impact survival, but that coinfection with nematodes would negatively impact survival, and that increased food availability would mitigate the negative effects of coinfection. Surprisingly, we demonstrated that PUUV infected voles had substantially reduced survival when compared to uninfected voles, and this strong negative effect manifested in young voles. Nematode removal increased survival of young voles and food supplementation interacted with movement rather than survival. Our results provide empirical evidence in a natural system for infection reducing survival of its reservoir host.

Background: Dengue emerged as a new public health threat in the Rohingya refugee camps in Coxs Bazar, Bangladesh, in 2021 and expanded into large-scale upsurges in subsequent years. Evidence on dengue epidemiology and clinical presentation in protracted refugee settings remains limited, despite the need for stronger outbreak preparedness and case management in these contexts. Objectives: To describe the epidemiological, clinical, and diagnostic characteristics of the dengue upsurge among Rohingya refugees and surrounding host communities in Coxs Bazar, Bangladesh, and to identify predictors of inpatient admission and diagnostic positivity patterns. Methods: This retrospective observational study used anonymized surveillance data from the International Organization for Migration (IOM) dengue patient database. Rapid diagnostic test (RDT)-confirmed dengue cases identified across 36 IOM-supported health facilities in Ukhiya and Teknaf between 1 October 2021 and 31 December 2024 were included. Demographic, epidemiological, clinical, and laboratory variables were summarized using descriptive statistics. Weekly incidence was aggregated by epidemiological week and calendar year, and epidemic growth and decay phases were modelled using phase-specific Poisson regression. Multivariable logistic regression was used to identify predictors of inpatient admission and to examine associations between delay in presentation and RDT positivity patterns, adjusting for age and sex. Results: A total of 35,581 RDT-confirmed dengue cases were reported, of which 90.2% occurred among Rohingya refugees. The median age was 17 years (IQR 7-30), and 46.0% of cases were among children aged 0-14 years. Annual caseload increased from 1,011 in 2021 to 11,752 in 2022, 10,669 in 2023 and 12,149 in 2024, with seasonal peaks during the monsoon period and progressively later peaks and longer epidemic tails over time. Poisson models showed decreasing growth rates across years (r=0.449 in 2021 to r=0.091 in 2024) with increasing doubling times, while decay rates remained broadly comparable (halving time ~4.4-6.0 weeks). Overall, 8.0% of cases required inpatient admission, 1.3% were referred, and four deaths were reported (case fatality <0.1%). In multivariable analysis, inpatient admission was associated with older age ([&ge;]60 vs 0-14: aOR 2.31), delayed presentation (aOR 1.06 per day), refugee status (aOR 1.39), presence of any World Health Organization (WHO) warning sign (aOR 26.60), low systolic BP (aOR 2.84) and chronic co-morbidity (aOR 6.07). In addition, males had lower odds of admission than females (aOR 0.88). NS1 antigen alone was positive in 62.1% of cases, IgM alone in 33.6%, and dual positivity in 4.3%. Longer delay from symptom onset to presentation was strongly associated with IgM-only positivity compared with NS1-only positivity (adjusted models controlling for age and sex). Conclusion: Sustained dengue preparedness is required in Coxs Bazar, including strengthened surveillance, community-based early referral, targeted monitoring of high-risk groups, environmental vector control, and phase-appropriate use of NS1 and IgM/IgG diagnostics to reduce missed diagnoses and prevent progression to severe disease. These findings highlight the need for a policy shift from episodic outbreak response toward sustained dengue preparedness in humanitarian settings, including strengthened surveillance systems, integrated diagnostic strategies, community-based early referral, and coordinated vector control interventions.

1Canine atopic dermatitis (CAD) is a chronic inflammatory skin condition sometimes associated with microbial dysbiosis, including alterations in colonization by the lipophilic yeast Malassezia pachydermatis. This study investigated the population diversity of M. pachydermatis in the ear canals of healthy and CAD-affected dogs using Fourier-transform infrared (FTIR) spectroscopy and whole genome sequencing (WGS). Among 60 dogs, M. pachydermatis prevalence was significantly higher in CAD cases than in healthy controls. FTIR spectroscopy revealed greater strain heterogeneity in CAD-affected dogs, often with distinct genotypes in each ear, while healthy dogs exhibited more homogeneous populations. Using a previously developed FTIR-based artificial neural network classifier, we assigned strains to three phylogroups. Strains from phylogroups I and III were significantly enriched in CAD-affected dogs, while phylogroup II was most prevalent overall and the dominant phylogroup in healthy controls. This suggests that CAD-associated inflammation may favor specific M. pachydermatis phylogroups and sub-clusters within phylogroups, shaping colonization dynamics. FTIR-based typing showed full concordance with WGS across 35 sequenced isolates, recapitulating relationships among phylogenetically related isolates and their similar phenotypic profiles. Overall, our findings reveal strain-level shifts in M. pachydermatis populations associated with CAD and establish FTIR spectroscopy as a rapid, cost-effective tool for large-scale epidemiological studies.

Introduction Nontyphoidal Salmonella enterica (NTS) is a major zoonotic enteric pathogen. Animal contact-related NTS outbreaks have increased in the United States of America (U.S.) over the last decade. Geospatial analysis can identify locations with elevated risk of NTS outbreaks where public health authorities can focus their NTS prevention and intervention efforts. Methods We analyzed NTS outbreak data reported from individual states to the Centers for Disease Control via the National Outbreak Reporting System between 2009 and 2022 across the continental contiguous U.S. A geospatial analytical framework that included disease mapping, spatial interpolation, and global and local clustering methods was applied to identify regions with high NTS outbreak rates. Results A total of 104 NTS single-state outbreaks were reported to the National Outbreak Reporting System (NORS) during the study period. The mean annual incidence rate was 0.02 NTS outbreaks per million person-years. The primary animal contact categories associated with these outbreaks were mammals (cattle, pigs, sheep, and horses), birds (backyard chickens, ducklings, and turkeys), and reptiles (turtles and lizards). Exposure settings included farms, fairgrounds, agricultural feed stores, veterinary clinics, dairy/agricultural settings, and residential settings. The local cluster detection methods consistently identified areas with significantly high NTS animal contact-related outbreak rates in the Mountain West, Midwest, and Northeast of the US. Conclusion NTS animal contact-related single-state outbreaks revealed distinct spatial clustering across the United States, with potentially higher risks in the Mountain West, Midwest, and Northeast. Diversity of animal-contact sources and exposure settings depicted complex transmission dynamics of NTS. Focused prevention and control programs in these areas are needed to mitigate the burden of NTS outbreaks.

Hantavirids, specifically the members within the genus Orthohantavirus, represent a significant global public health threat, with bat-associated lineages challenging traditional reservoir paradigms. To investigate the genetic diversity of hantavirids in Southeast Asia, we conducted an expanded surveillance program in Lao PDR from May 2023 to October 2025 in bat populations and wild animals from local wet markets. Using molecular screening and deep sequencing to characterize hantavirids from bat populations and wild animals from local wet markets, we identified 20 positive samples across four bat species, recovering coding-complete genomes for multiple novel variants. Phylogenetic analysis confirmed that these viruses form a monophyletic group within Mobatvirus, resolving into two major subclades. The first subclade clustered with Quezon and Robina viruses found in fruit-eating bats. The second subclade further split into two lineages corresponding to Thakrong and Xuan Son viruses, which are associated with trident and leaf-nosed bats, respectively. Despite the strong host specificity observed, the detection of these viruses in a wet market, a critical interface for human-wildlife contact, indicates a potential zoonotic risk. These findings significantly expand the known diversity of mobatviruses in Laos and highlight the urgent need for serological surveillance in at-risk human populations to assess the potential for spillover.

The accurate measurement of Ebola virus (EBOV)-specific antibody responses is crucial to assessing immunity induced by EBOV infection or vaccination. For this purpose, the Filovirus Animal Nonclinical Group (FANG) anti-EBOV glycoprotein (GP1,2) ELISA is considered the "gold-standard". However, it has limitations such as high repeat-rates and variability, and low throughput. Here, we describe two new alternative assays: a Single-Molecule Assay Planar EBOV GP1,2 ELISA and a multiplexed EBOV GP1,2, EBOV nucleoprotein, and EBOV Viral Protein 40 Luminex assay, and compare these with two versions of the FANG ELISA. Samples were selected from participants receiving vaccine or placebo in a randomized, placebo-controlled, double-blinded study of two EBOV vaccines (PREVAIL 1), and a longitudinal cohort study of Ebola virus disease (EVD) survivors and their close contacts (PREVAIL 3). All four assays were concordant in their measurements of anti-EBOV GP1,2-specific immunoglobulin G responses, allowing for the determination of conversion equations for antibody measurements across assays. In addition, all four showed a similar ability to distinguish vaccine recipients from placebo recipients and EVD survivors from their close contacts. Compared to the FANG assays, the Quanterix and Luminex assays had lower variability, lower repeat rates, and higher throughput, making them good alternatives for future studies.

Helminths are parasitic worms that secrete a variety of immune-regulating molecules to modulate the hosts inflammatory responses, enabling them to persist within the host over a long period of time, even decades. Their capacity to control host responses has prompted research into helminth-derived molecules as potential therapies for controlling excessive immune and inflammatory activity across a range of diseases. This systematic review with cross-study quantitative analysis aims to synthesize the published data on helminth-derived immunomodulatory peptides/polypeptides/proteins (HDIPs) with a focus on determining the extent of their disease-modifying and anti-inflammatory potential in in vivo animal models of inflammatory disease. In accordance with PRISMA 2020 guidelines, a predefined systematic search of the PubMed, Web of Science and Medline databases identified relevant studies published up to February 2026, and 65 articles were included after screening. We found that, although the HDIPs were assessed in multiple different disease models, most published studies assessed their potential in mouse models of colitis, asthma, arthritis and sepsis. Twenty species from which >65 isolated HDIPs were derived were tested in these models, with the trematode, Fasciola hepatica, and the nematode, Acanthocheilonema viteae, the most explored species. A common property of the HDIPs was the ability to significantly reduce disease severity across the in vivo animal models of inflammatory disease, underpinned by a decrease in pro-inflammatory cytokine levels and an increase in anti-inflammatory cytokine levels. Overall, this systematic review with cross-study quantitative analysis not only synthesizes the existing literature in this field but also highlights the disease-modifying and anti-inflammatory potential of HDIPs for a range of diseases in which immunoregulatory therapeutics may improve disease outcomes. It also encourages accelerated advancement of these helminth-derived molecules into first-in-human clinical trials.

Plasmodium vivax transmission from humans to mosquitoes depends on the density of gametocytes that in turn depends on asexual parasite replication and gametocyte commitment. These processes are often analyzed separately, despite being biologically linked and measured with substantial uncertainty. We used a joint Bayesian latent-variable model to simultaneously analyze parasite density, gametocyte density, and mosquito infectivity while accounting for measurement error and propagating uncertainty across linked processes. The model was applied to individual-level data from three P. vivax transmission studies conducted in Ethiopia (n = 455). A tenfold increase in gametocyte density was associated with more than a twofold increase in the odds of mosquito infection (odds ratio [OR] = 2.32, 95% credible interval [CrI]: 2.12-2.54). Asexual parasite density was also positively associated with infectivity after accounting for gametocyte density (OR = 1.74, 95% CrI: 1.60-1.90), and inclusion of parasite density improved predictive performance. Pathway decomposition within the joint model indicated that approximately 41% of the parasite-infectivity association operated through gametocyte density. Increasing age was associated with lower asexual parasite density but higher gametocyte density, resulting in minimal overall association with infectivity. Predicted infection probability increased sigmoidally with gametocyte density, remaining low at lower densities before increasing sharply and approaching a plateau at higher densities. Gametocyte density produced the largest predicted changes in the proportion of infected mosquitoes, while asexual parasite density added predictive information not fully captured by measured gametocyte density alone. This approach links molecular parasite measurements with mosquito infection risk while accounting for measurement uncertainty and provides an interpretable framework for studying the P. vivax infectious reservoir. Author SummaryMalaria transmission occurs when mosquitoes ingest sexual-stage parasites, called gametocytes, during a blood meal. In Plasmodium vivax infections, human-to-mosquito transmission depends on linked biological stages, including asexual parasite replication, gametocyte production, and mosquito infection. These processes are closely connected and often measured with uncertainty, making them difficult to study using standard approaches that analyze them separately. In this study, we applied a joint Bayesian model that analyzes parasite density, gametocyte density, and mosquito infectivity together while accounting for uncertainty in laboratory measurements. Using data from three studies in Ethiopia, we quantified how parasite density, gametocyte density, and host characteristics relate to mosquito infection. The analysis showed that measured gametocyte density alone did not fully explain variation in infectivity, and that asexual parasite density provided additional predictive information. We also found that age was associated differently with asexual parasite and gametocyte densities, resulting in little overall association with infectivity. This approach helps link molecular parasite measurements with transmission outcomes and improves understanding of the P. vivax infectious reservoir in endemic settings.

Astyanax Baird & Girard, 1854 is a widely distributed and species-rich genus of Acestrorhamphidae, whose abundant populations in Neotropical basins play a crucial ecological role at the trophic level. Taxonomic uncertainties persist within the genus, as seen in Astyanax sp. (formerly designated as A. fasciatus) from the Magdalena basin in Colombia. Concerns about its genetic status are heightened due to ecological threats posed by hydroelectric dams, from habitat loss to river connectivity. We isolated and characterized 17 microsatellite loci to assess the population genetics of this species in a broad sample from the middle and lower sections of the Cauca River, now interrupted by the Ituango dam. Furthermore, a multidisciplinary approach integrating phylogenetic analyses of mitochondrial (COI) and nuclear (rag2) markers with geometric morphometric analyses was employed to evaluate potential cryptic diversity within Astyanax sp. Microsatellites revealed two genetic groups in the studied area, strongly supported as distinct lineages by phylogenetic analyses. Unexpectedly, one of these lineages of Astyanax sp. was recovered in an unresolved clade with samples of A. microlepis and allopatric samples of A. viejita from the Maracaibo Lake basin. Each genetic group showed high genetic diversity, but also evidence of recent bottleneck events and significant-high values of inbreeding. Morphometric analyses provided evidence of significant phenotypic differentiation among A. microlepis, Astyanax sp. 1 (Asp1), and Astyanax sp. 2 (Asp2). Morphological patterns ranged from the robust profile of A. microlepis to the streamlined shape of Astyanax sp. 2 (Asp2), with Astyanax sp. 1 (Asp1) displaying intermediate traits and localized differences in head length and fin placement. Statistical support from permutation tests and a high overall classification accuracy (95.65%) underscore the existence of distinct morphospecies, suggesting that phenotypic differentiation is well-established, despite the complex evolutionary history of the group. This study suggests the presence of cryptic diversity within Astyanax sp. and provides valuable genetic information for the conservation and management of their populations in the Magdalena basin.

Measurement of antibody responses to viral infection is essential for surveillance, diagnostics, epidemiological research, and natural history of infection studies. However, current methods to detect virus-specific antibodies are often resource-intensive and impractical for deployment in outbreak settings or in field-based studies. This manuscript presents two economical, high-throughput immunoassays--the cytoblot immunoassay (CBA) and strip immunoblot assay (SIA)--for detecting and quantifying anti-lymphocytic choriomeningitis mammarenavirus (LCMV) antibodies in mouse serum. To validate, we tested serum from acutely or persistently experimentally infected mice. Both assays detected LCMV-specific IgG and IgM antibodies with high sensitivity and specificity across multiple timepoints. By facilitating the study of immune responses in rodent reservoirs, these tools can enhance our understanding of zoonotic viral transmission, provide scalable platforms for outbreak preparedness, and serve as adaptable models for the development of rapid serological assays for other viral pathogens.