Epidemic arboviruses such as dengue (DENV), zika (ZIKV), and chikungunya (CHIKV) are maintained between humans and Aedes aegypti mosquitoes and have great impact on public health in Brazil. In addition to these epidemic arboviruses, enzootic arboviruses such as yellow fever (YFV), mayaro (MAYV), and oropouche (OROV) viruses, that circulate between wildlife and bloodsucking dipterans, are also of great medical concern in the country. If these viruses circulate in synanthropic vertebrate species, and if these animals play a role in arboviruses transmission cycles, remains unclear. Bats are commonly found in large populations at the animal–human interface, so their exposure to arboviruses merits continuous surveillance. Between 2017 and 2018, we investigated the circulation of Brazil’s important arboviruses in bats (n=189) collected at the human–animal interface areas of Midwest Brazil. Carollia perspicillata and Artibeus lituratus were the most common species captured. Using RT-qPCR assays, we conducted a molecular screening for DENV, ZIKV, CHIKV, YFV, MAYV, and OROV RNA in liver, kidney, and brain samples of free-ranging bats. Additionally, plasma of 79 bats were tested by plaque reduction neutralization test (PRNT) for specific neutralizing antibodies for OROV and plasma of 73 bats were tested for MAYV. All tissue specimens tested negative by RT-qPCR suggesting no current infections by any of the arboviruses tested. All bats presented PRNT90 titer <20 for OROV and MAYV and therefore considered seronegative. Plaque reduction below the predefined threshold for seropositivity for MAYV was observed in several individuals and merits further investigation. Plasma samples from 67 other bats also presented plaque reduction for MAYV that could not be confirmed due to limited sample volume for serial dilution in PRNT. The absence of active infection by arboviruses associated with the large number of bats presenting plaque reduction for MAYV merits further investigation.
We carried out a viral surveillance study on 30 black-horned capuchin monkeys (Sapajus nigritus) in Rio Doce State Park, a protected area in the Brazilian Atlantic Forest. Samples were tested for orthopoxviruses, flaviviruses, coronaviruses, influenza viruses, and a wide range of other respiratory viruses using molecular and serological methods. RT-qPCR detected the respiratory syncytial virus (RSV) genome in oral swabs from two asymptomatic juvenile females sampled in an area with high human interaction. This finding indicates a possible exposure of an population to RSV, a contagious human pathogen, and highlights the importance of increased surveillance at the human–wildlife interface.
Lassa fever remains a major public health concern in Nigeria, where climatic variability, ecological dynamics, and socio-behavioral factors combine to influence transmission patterns. This review synthesizes current evidence on how atmospheric conditions shape Lassa fever incidence through their effects on ecosystems, rodent reservoirs, and human exposure pathways. Drawing on studies in epidemiology, disease ecology, climate science and remote sensing, the review highlights that temperature, rainfall, humidity, vegetation change and large-scale climatic oscillations all contribute to fluctuations in Mastomys natalensis populations which serve as the primary reservoir of Lassa virus. These climatic drivers modify food availability, breeding cycles and habitat suitability for rodents which in turn affect the probability of viral spillover. Modeling approaches including statistical regression, time series analysis, ecological niche modeling and spatiotemporal remote sensing demonstrate that environmental variables significantly improve predictions of disease risk. However, important gaps remain including limited long-term ecological data, underreporting in surveillance systems, insufficient integration of rodent ecology with climate data and a need for more comprehensive socio-behavioral studies. The review recommends future directions such as sustained monitoring of Mastomys populations, high-resolution climate-sensitive modeling, genomic analysis of Lassa virus across climatic gradients and multidisciplinary approaches that combine environmental science with public health research. Improving climate-informed surveillance and early warning systems is essential for strengthening preparedness and reducing the burden of Lassa fever in Nigeria.
Rift Valley fever (RVF) remains one of the most recognisable yet persistently elusive zoonotic diseases in Africa, despite decades of scientific advances in virology, epidemiology, and early warning. While RVF dynamics are well characterised in eco-epidemiological terms, its continued emergence, amplification, and persistence suggest that biological complexity alone does not fully explain ongoing transmission patterns. This review adopts a socio-ecological One Health systems perspective to examine how interactions between eco-epidemiological processes, livestock mobility, and health governance structures shape RVF risk. Drawing on an integrative synthesis of interdisciplinary literature, it conceptualises RVF dynamics as arising from three interconnected domains: biological risk generation, spatial redistribution through mobility and trade systems, and institutional response through governance architectures. The analysis highlights a fundamental misalignment across these domains. Ecological signals and animal health indicators often precede outbreaks but are not translated into timely action; livestock mobility redistributes risk across regions beyond the reach of nationally bounded response systems; and governance arrangements remain fragmented, with no single institution holding end-to-end responsibility. As a result, RVF response remains largely reactive and case-triggered despite the availability of predictive tools and preventive interventions. Addressing this persistent gap requires a shift from reactive, case-chasing response toward anticipatory, integrated governance that aligns ecological intelligence, mobility-informed risk management, and coordinated cross-sectoral action. Viewing RVF through this systems lens underscores that its persistence reflects less a failure of knowledge than a failure of alignment between the systems through which risk is generated, redistributed, and governed.
The present study evaluated 63 shrimp aquaculture farm sites in the Thrissur and Alappuzha districts of Kerala State, India. A total of 206 samples were analyzed, and 50 extended-spectrum β-lactamase (ESBL)-producing Escherichia coli strains were identified with antibiotic susceptibility testing (AST) profiles. All the strains were multidrug-resistant (MDR), with multiple antibiotic resistance (MAR) indices ranging from 0.32 to 0.64. PCR detection revealed a high prevalence of ESBL genes, blaCTX-M-gp-1 (86
