Prevalence of Flavivirus and Alphavirus in bats captured in the state of Yucatan, southeastern Mexico

Flavivirus (family Flaviviridae) and Alphavirus (family Togaviridae) are mosquito-borne viruses that poses a significant risk to public health worldwide. Examples of these viruses include Dengue virus (DENV) and Zika virus (ZIKV) in the Flavivirus genus, and Chikungunya virus (CHIKV) in the Alphavirus genus. The potential contribution of bats in the mosquito-to-human transmission cycle of these viral genera in the tropics has not been studied. Here, a total of 144 bats belonging to three families (Emballonuridae, Phyllostomidae, and Molossidae) and six species were captured for one year using mist nets in sites with different landscapes (forest and grassland) in the state of Yucatan, southeastern Mexico. Blood samples and rectal and oral swabs were collected to detect Flavivirus and Alphavirus RNA genomes through RT-PCR. Flavivirus RNA was detected in 53 individuals (36.8%; 95% CI: 29.4%–44.9%), and Alphavirus RNA was detected in 59 individuals (40.1%; 95% CI: 33.2%–49.2%). The sequences obtained were consistent with ZIKV and DENV, into the Flavivirus, and CHIKV into the Alphavirus positive samples. The prevalence of both Flavivirus and Alphavirus was higher during the dry season compared with the rainy season. This high positivity rate, highlighted in both Flavivirus and Alphavirus, suggests a potential contribution of bats in the circulation of these viral genera in sylvatic environments. Seasonal variation in viral genera prevalence, with higher prevalence during dry seasons than rainy seasons, may suggest specific viral activity patterns in response to climatic conditions.