Final answer:
West Nile virus is primarily transmitted by Culex mosquitoes, which are vectors that spread the virus from birds to humans. Preventative measures include using approved insect repellent and wearing protective clothing.
Step-by-step explanation:
The pathogen involved in West Nile virus is transmitted through vectors. The primary vector for transmitting West Nile virus is the Culex mosquito, which picks up the virus from an infected bird and then transmits it to humans through a mosquito bite. To avoid contracting West Nile virus, it is important to take measures to prevent mosquito bites, such as using approved insect repellent, wearing proper clothing that covers the skin, and eliminating standing water where mosquitoes can breed.