How do people become infected with West Nile Virus?
People become infected with WNV from the bite of an infected mosquito. Birds and other animals cannot transmit WNV to people. In 2002, a small number of people in the United States became infected with WNV when receiving blood products or organs from WNV infected donors. In 2003, a blood testing program was initiated to screen blood products for WNV prior to transfusion.
