How is West Nile virus primarily transmitted?

West Nile virus is primarily transmitted through mosquito bites. This virus is commonly carried by certain species of mosquitoes, which become infected after biting birds that are hosts for the virus. Once a mosquito is infected, it can then transmit the virus to humans and other animals through its bite. This transmission method is significant because it entails an interaction between several species, specifically the avian hosts and the mosquitoes, which are the vectors.

Understanding that direct contact with infected animals, consuming contaminated water, or airborne transmission do not play a primary role in the virus's lifecycle is essential. While animals can harbor the virus and may even exhibit symptoms, they are not direct sources of transmission to humans without the mediation of mosquitoes. This distinction reinforces the importance of mosquito control measures to reduce the risk of West Nile virus infection, especially in areas where the virus is endemic.