Global distribution of flaviviruses in wild mammals

Flavivirus genus (family Flaviviridae) infects a wide range of invertebrate and vertebrate hosts and it is associated with severe human and animal diseases (e.g. Dengue virus, DENV; Japanese encephalitis virus, JEV). Although... [ view full abstract ]

Flavivirus genus (family Flaviviridae) infects a wide range of invertebrate and vertebrate hosts and it is associated with severe human and animal diseases (e.g. Dengue virus, DENV; Japanese encephalitis virus, JEV). Although these viruses are known to affect several wild mammal species worldwide, global distribution patterns and infection dynamics are barely known.
Our aim is to address the distribution of flaviviruses (except WNV) across wild mammals to generate a database useful to understand biogeographical patterns, to identify host susceptibility and phylogenetic signals that may help decision-makers to prevent and predict future outbreaks.
We searched scientific publications in the ISI Web of Knowledge and we used a keyword combination including: name of each flavivirus recognized by ICTV, and “mammal” or “rodent” or “bat”. We included papers reporting serology, molecular and isolation tests of flaviviruses (except WNV) among wild mammal species. We excluded review articles, experimental studies, and reports in zoo mammals.
We found reports of 33 recognized flaviviruses among 132 different wild mammal species captured in 35 different countries. We found reports of 10, 9, 5, and 16 flaviviruses in Africa, Asia, Europe and America, respectively. Bats, primates, rodents and artiodactyls are most susceptible mammal orders. Mosquito-borne and tick-borne flaviviruses are primarily distributed in Neotropics and Neartics, respectively. Zoonotic flaviviruses were the most reported: tick-borne encephalitis virus, DENV, Powassan virus, and St. Louis encephalitis virus.
Global distribution of flaviviruses recognized in wild mammals is due to incidental findings and epidemiological studies, but ecological studies to understand infection dynamics are lacking. More studies are needed in order to find patterns of distribution at different spatial scales. This baseline database will influence decision-making processes and we will use it to determine risk areas for flavivirus emergence, to determine which mammalian species are more involved, and to search possible flavivirus-host associations.