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While urban expansion increasingly encroaches on natural habitats, many wildlife species capitalize on anthropogenic food resources, which have the potential to both positively and negatively influence their responses to infection. Here we examine how food availability and key nutrients have been reported to shape innate and adaptive immunity in wildlife by drawing from field-based studies, as well as captive and food restriction studies with wildlife species. Examples of food provisioning and key nutrients enhancing immune function were seen across the three study type distinctions, as were cases of trace metals and pharmaceuticals impairing the immunity of wildlife species. More generally, food provisioning in field studies tended to increase innate and adaptive responses to certain immune challenges, whereas patterns were less clear in captive studies. Mild food restriction often enhanced, whereas severe food restriction frequently impaired immunity. However, to enable stronger conclusions we stress a need for further research, especially field studies, and highlight the importance of integrating nutritional manipulation, immune challenge, and functional outcomes. Despite current gaps in research on this topic, modern high throughput molecular approaches are increasingly feasible for wildlife studies and offer great opportunities to better understand human influences on wildlife health. This article is part of the theme issue ‘Anthropogenic resource subsidies and host–parasite dynamics in wildlife’.

We report a novel orthohantavirus, putatively named Ozark orthohantavirus, in hispid cotton rats captured within the Ozark Plateau in Arkansas, USA. This virus phylogenetically clusters with other orthohantaviruses that cause severe human disease. Continued orthohantavirus surveillance and virus sequencing are needed to address the potential public health threat of this virus.

We found similar mild perivascular inflammation in lungs of Bombali virus-positive and -negative Mops condylurus bats in Kenya, indicating the virus is well-tolerated. Our findings indicate M. condylurus bats may be a reservoir host for Bombali virus. Increased surveillance of these bats will be important to reduce potential virus spread.

Dengue fever is one of the most globally significant arthropod-borne viral diseases. In 2024, more than 14 million cases and 10,000 deaths were reported across 92 tropical and subtropical countries. Dengue virus (DENV), endemic in Sub-Saharan Africa including Kenya, comprises four serotypes (DENV-1 to DENV-4). While DENV-1 to DENV-3 are widely distributed in the region, DENV-4 is considered rare. However, information on the distribution of DENV serotypes and the genetic diversity within African mosquito populations remains limited. To address this gap, 2,400 Aedes aegypti, the primary vector species of DENV, were collected from southeastern and coastal Kenya between 2016 and 2019 and subjected to viral analyses. Collected samples were screened for orthoflaviviruses using a nested pan-orthoflavi RT-PCR, and positive samples were Sanger sequenced. DENV-4 genotype I was detected in a pool of two female Ae. aegypti collected during a dengue outbreak in Mombasa in 2017, which was predominantly associated with DENV-2 . The DENV-4 genome retrieved from this strain was similar to sequences of DENV-4 that have previously been reported from South India. We report the detection and genomic characterization of DENV-4 genotype I in Kenyan mosquito populations. These findings contribute to current knowledge of DENV serotype distribution in southeastern Africa and highlight the need for improved genomic surveillance to guide effective dengue prevention and control strategies.

Previously identified only in Sierra Leone, Guinea, and southeastern Kenya, Bombali virus-infected Mops condylurus bats were recently found »750 km away in western Kenya. This finding supports the role of M. condylurus bats as hosts and the potential for Bombali virus circulation across the bats' range in sub-Saharan Africa.

Bats harbor viruses that can cause severe disease and death in humans including filoviruses (e.g., Ebola virus), henipaviruses (e.g., Hendra virus), and coronaviruses (e.g., SARS-CoV). Bats often tolerate these viruses without noticeable adverse immunological effects or succumbing to disease. Previous studies have largely focused on the role of the bat’s innate immune response to control viral pathogenesis, but little is known about bat adaptive immunity. A key component of adaptive immunity is the humoral response, comprised of antibodies that can specifically recognize viral antigens with high affinity. The antibody genes within the 1,400 known bat species are highly diverse, and these genetic differences help shape fundamental aspects of the antibody repertoire, including starting diversity and viral antigen recognition. Whether antibodies in bats protect, mediate viral clearance, and prevent transmission within bat populations is poorly defined. Furthermore, it is unclear how neutralizing activity and Fc-mediated effector functions contribute to bat immunity. Although bats have canonical Fc genes (e.g., mu, gamma, alpha, and epsilon), the copy number and sequences of their Fc genes differ from those of humans and mice. The function of bat antibodies targeting viral antigens has been speculated based on sequencing data and polyclonal sera, but functional and biochemical data of monoclonal antibodies are lacking. In this review, we summarize current knowledge of bat humoral immunity, including variation between species, their potential protective role(s) against viral transmission and replication, and address how these antibodies may contribute to population dynamics within bats communities. A deeper understanding of bat adaptive immunity will provide insight into immune control of transmission and replication for emerging viruses with the potential for zoonotic spillover.

Bats are associated with some of the most significant and virulent emerging zoonoses globally, yet research and surveillance of bat pathogens remains limited across parts of the world. We surveyed the prevalence and genetic diversity of coronaviruses from bats in Taita Hills, southeastern Kenya, as part of ongoing surveillance efforts in this remote part of eastern Africa. We collected fecal and intestinal samples in May 2018 and March 2019 from 16 bat species. We detected one genus of coronavirus (alphacoronavirus), with an overall RNA prevalence of 6.5% (30/463). The prevalence of coronavirus RNA was 3.8% (9/235) and 11.6% (21/181) for the two most captured free-tailed bat species, Mops condylurus and M. pumilus respectively, with no detections from other bat species (0/90). Phylogenetic analyses based on the partial RNA-dependent RNA polymerase gene and whole genome sequences revealed that the sequences clustered together and were closely related to alphacoronavirus detected in free tailed bats in Eswatini, Nigeria and Rhinolophus simulator bats in South Africa. The sequences were more distantly related to alphacoronavirus isolated from Chaerophon plicatus bat species in Yunnan province, China and Ozimops species from southwestern Australia. These findings highlight coronavirus transmission among bats that share habitats with humans and livestock, posing a potential risk of exposure. Future research should investigate whether coronaviruses detected in these bats have the potential to spillover to other hosts.

Anthropogenic food subsidies can have profound influences on wildlife behavior and health, including exposure to parasites. In many host–macroparasite systems, parasite exposure is tied to foraging behavior, but how different distributions of food subsidy shape macroparasite encounter and population‐level impacts is poorly understood. Here we modify a mathematical model of macroparasite transmission to explore how food subsidies could change parasite encounter rates and between‐host variation in parasite burdens, reflecting changes in host foraging and conspecific overlap. Hosts experience the highest average parasite abundance and associated reductions in population size when food subsidies increase and homogenize parasite encounter rates, for example when hosts center their home ranges on a point food source and overlap with many conspecifics. Conversely, hosts experience the lowest parasite abundance and impacts when subsidies result in lower and more heterogeneous parasite encounter rates, for example when multiple patchily distributed subsidies subdivide host populations and increase host commute times to food at the expense of time spent foraging. Even when resources affect other processes such as improving host immunity or fecundity, the overall effect of subsidies on infection is more strongly driven by changes in parasite encounter rates through altered foraging behavior. These patterns are robust to different effect sizes of resource subsidy on foraging and nonforaging parameters. Our findings demonstrate that resource‐driven shifts in host foraging behavior could play an integral role in determining infection dynamics for parasites with environmental (free‐living) infectious stages, with consequences for wildlife provisioning in recreational, conservation, and management contexts. Wildlife behavioral responses to different distributions of food subsidies could shape encounter and infection intensity of environmentally transmitted parasites. Using a mathematical model, we show that the way in which food subsidy changes transmission rate and variation in parasite burdens (e.g., through changes in time spent foraging and variation in conspecific overlap) determines host and parasite abundance. Moreover, these behavioral responses to food subsidy typically outweigh other effects of food subsidy on immunity and host or parasite fitness, with implications for how food provisioning is managed across landscapes.