Florian, L. | bioRxiv Science

bioRxiv2023

Longitudinal Survey of Astrovirus infection in different bat species in Zimbabwe: Evidence of high genetic Astrovirus diversity

Astroviruses (AstVs) have been discovered in over 80 animal species including diverse bat species and avian species. A study on Astrovirus circulation and diversity in different insectivorous and frugivorous chiropteran species roosting in trees, caves and building basements was carried out at 11 different sites across Zimbabwe. Pooled and individual faecal sampling methods were used for this study, with collection dates ranging from June 2016 to July 2021. In two sites, Magweto and Chirundu, sampling was carried out at monthly intervals from August 2020 to July 2021. Astroviruses and bat mitochondrial genes were amplified using pan-AstVs and CytB /12S RNA PCR systems respectively. Phylogenetic analysis of the RdRp Astrovirus sequences revealed a high genetic diversity of astroviruses. All the bat astroviruses tested in this study clustered with the Mamastrovirus genus. Two distinct groups of amplified sequences were identified. One group was comprised of sequences isolated from Hipposideros, Rhinolophus and Eidolon helvum spp. clustered with Human Astrovirus strains: HuAstV types1-6, HuAstV-MLB1-3 and HuAstV-VA-1. The second group comprising the majority of the sequences clustered with different strains of Bat AstVs. Results from the longitudinal study at Magweto and Chirundu showed an overall AstV prevalence of 13.7% and 10.4% respectively. Peaks of AstV infection at Chirundu coincided with the period when juveniles are 4-6 months old. By combining data from our previous work on Coronaviruses, we also anaylzed co-infection of bats with Coronaviruses and Astroviruses at Magweto and Chirundu sites for which the prevalence of co-infection was 2.6% and 3.5% respectively.

molecular biology↗

bioRxiv2022

Prevalence and public health significance of Lyssavirus in bats in North region of Cameroon

BackgroundRabies is a zoonotic disease of all warm-blooded animals including humans. Though, there is little knowledge of the status of rabies in wild animals in Cameroon, the disease is endemic in the country with dogs being the main source of transmission. Bat habitats are widespread in Cameroon, but there is little information on the prevalence of rabies-like viruses in bats, nor the role of bats as a potential reservoir of rabies. MethodsA cross sectional study was carried out to determine the prevalence and risk factors of Lyssavirus in bats in the Northern region of Cameroon. A total of 212 bats belonging to three families (Pteropodidae, Vespertilionidae, Molossidae) and 5 species were randomly sampled in 7 localities in the North of Cameroon and were tested for Lyssavirus antigen using direct Immunofluorescence Test (IFA). Overall, 57 (26.89%) of the bats collected showed an IFA positive reaction. The prevalence was higher (P<0.05) in adult bats (33.33%, 95% CI: 25.15 - 42.66) compared to young individuals (20.19%). The main risk factors identified in the study for human exposure to bats were gender (Male), educational level (tertiary), religion (Christianity), ethnic group (Matal), the presence of bats in the area, the practice of bat hunting and consumption and the level of awareness on bat rabies-like viruses. ConclusionThe study found the first evidence of Lyssavirus in bats in Cameroon. This finding revealed that bat rabies-like viruses are real and constitutes a potential human health problem in communities with bat habitats in the North region of Cameroon. Enhancing the level of public awareness and health education on the potential of bats as reservoirs of Lyssavirus in Cameroon as well as the integration of the "One Health" approach for effective management of animal and human rabies should be emphasized. Author summaryRabies is a zoonotic disease caused by a virus of the genus Lyssavirus. It affects all warm-blooded animals including humans. Canine and Human rabies are well documented as endemic in Cameroon, but little is known about this disease in wildlife, in particular among bats, despite their multiple interactions with the inhabitants of Northern Cameroon. Indeed, bats were hunted, sold and eaten as bush meat by local populations. We investigated the presence of Lyssavirus in bat and assessed the risk factors of human exposure to bats in the Northern region of Cameroon. The study highlights that Lyssavirus is present in bats in this area. The population was aware of human and canine rabies, however, the presence of the disease in bats was less known. Based on these findings, investigating bat populations on a large scale, to characterise the Lyssavirus strains circulating in the region, as well as educate the local population on the risks of rabies transmission from bats to humans and other animals.

microbiology↗