Swine producers are fighting with a new virus that challenges even the best biosecurity. Flooding and wet conditions have supported an increase in mosquitoes which carry the virus.
Source: PORK, April 5, 2022. Link. The Japanese encephalitis virus is a flavivrus in the same family as West Nile virus, St. Louis encephalitis virus, and Murray Valley encephalitis virus. The virus is maintained in a cycle between mosquitoes and vertebrate hosts, mainly ardeid birds such as herons, egrets and bitterns.
There is spillover of JEV to other species including pigs, humans, horses and other domestic animals. Humans and horses are considered dead-end hosts because they usually do not develop high levels of viremia, while pigs are an amplifying host.