The first human infections of West Nile Virus (WNV) have been confirmed in two residents of Butte County after a routine blood donation. These are the first human infections of WNV reported this year.
Blood donation centers routinely check for viruses in the blood as a precautionary measure and do not retain any infected blood. The two people were unaware of their virus and are symptom free. Both infections are separate and unrelated to each other.
Reports as of July 15, 2015, WNV activity has been detected in 31 of California’s 58 counties, with 152 non-human cases of WNV infection. In Butte County, one dead bird and 15 mosquito samples have tested positive for the virus this year. Mosquito sampling is done throughout the county by the Butte County Mosquito and Vector Control District, with a majority of the positive samples coming from the southern part of the county.
“This is a timely reminder that we must do our best to prevent mosquito bites and protect ourselves and our families from WNV. The public should take extra precautions to avoid mosquitos,” said Dr.Lundberg, Butte County Health Officer. 80% of people infected with WNV do not have symptoms. People 50 years of age and older are more likely to develop serious symptoms if infected, however, all ages are vulnerable. WNV is transmitted to humans and animals through a mosquito bite. Mosquitoes become infected when they feed on infected birds. Residents can reduce the risk of infection by practicing the “Three Ds”: Use insect repellent like DEET, protect yourself at dusk and dawn from mosquito bites and “Drain”, eliminate sources of standing water.