More West Nile-carrying mosquitoes found in Merced following Nevada County death

Merced County’s Mosquito Abatement District said more mosquito pools in the area have tested positive for West Nile virus. The news comes on the heels of the state’s first confirmed death linked to West Nile this year.

The California Department of Public Health announced Monday that the death of a senior citizen from Nevada County is a reminder of how severe the disease can be.

“West Nile virus activity is more widespread in 2015 than in years past,” said Dr. Karen Smith, the CDPH’s director and state health officer. “Californians need to be vigilant in protecting themselves.”

Thirty-three California counties have reported West Nile virus activity so far this year, including Merced County. On Monday, Allan Inman, entomologist and manager at the the county’s abatement district, said a dead bird found near Neves Court in Atwater, near the McSwain area, tested positive for West Nile.

A pool of mosquitoes found near dairy land in Hilmar also tested positive. Earlier this month, the district issued a warning when virus-carrying mosquitoes were trapped near Merced College.

With all the activity going on in the Central Valley, a human case is only a matter of time, Inman said. Last year, one human case was confirmed in Merced County.

In California, 497 mosquito samples have tested positive for West Nile so far this year. This exceeds the five-year average of 330.

The virus, according to officials, is influenced by many factors such as climate, the number and types of birds and mosquitoes in an area, and the level of immunity in birds to West Nile.

The CDPH said the drought may be contributing to amplification of the virus by reducing sources of water for birds and mosquitoes. As birds and mosquitoes seek water, they come into closer contact, contributing to a higher possibility of infection.

According to the Centers for Disease Control and Prevention, most people infected with West Nile virus will have no symptoms. About one in five people who are infected will develop a fever, headaches or disorientation, and about 1 percent of infected people develop a serious neurological illness.

This story was originally published July 20, 2015 at 6:13 PM with the headline "More West Nile-carrying mosquitoes found in Merced following Nevada County death."