The Madera County Department of Public Health has confirmed its first fatality from West Nile virus this year. 

The adult male who had West Nile virus was one of the first two cases identified in August. Both required hospitalization, but the other individual has improved and was released from the hospital. The two cases were unrelated.

“We are saddened by this loss, and it is a reminder of the risks from WNV-infected mosquito bites. You can decrease your risk for WNV and other viruses transmitted by mosquitoes by using EPA-registered repellent to keep mosquitoes from biting you, mosquito proofing your home through the use of properly fitting doors and screens, and not allowing standing water to collect in your home or yard,” said Dr. Simon Paul, Madera County public health officer.

The California Department of Public Health reported a death from West Nile virus in July in San Luis Obispo County. 

The virus is transmitted to people through the bite of an infected mosquito. The California Department of Public Health said that the virus is influenced by climate, the number and types of birds and mosquitoes in an area, and the level of West Nile immunity in birds. As of July 9, the state had detected 45 dead birds from six counties and 177 mosquito samples from 13 counties. Heat can increase the risk of virus transmission to humans, the state reported.

The mosquito abatement control agency was contacted in August when the two cases were logged. The agency sprayed the areas where the positive tests originated. 

Most people with West Nile virus have no symptoms, but about 25% may show signs of headache or fever. Fewer than 1% of infections develop severe disease or symptoms such as stiff neck, confusion and decreased alertness.

People aged 50 or older and those who have a weakened immune system are at greater risk for experiencing severe symptoms. There is no vaccine for West Nile virus.