Mosquitoes at Merced College test positive for West Nile

A mosquito warning has been issued for the city of Merced after mosquitoes trapped at Merced College last week tested positive for West Nile virus, the Merced Mosquito Abatement District reported.

Officials at the abatement district received the test results Friday, said Allan Inman, an entomologist and manager at the district. It is the first indication of West Nile in Merced County this year, Inman said.

The mosquito abatement district has not found the source of the West Nile-positive mosquito. Inman said it could be from a swimming pool in a neighborhood near the college.

No known cases of human infections have been reported, he said.

The mosquitoes were trapped in the back loop of the campus near the farm, said Joanne Schultz, Merced College’s vice president of administrative services. The road to the farm is closed at night, and there’s not much opportunity for students to come into contact with mosquitoes after dark there, Schultz said.

During the week approaching the Fourth of July holiday, the Merced College campus is mostly empty. “There’s virtually no one here right now,” Schultz said.

Inman urged residents to be vigilant and report any standing water to the mosquito abatement district.

“We know what’s in people’s front yards, but we don’t know what’s in backyards,” he said. “We need people to be our eyes and ears in the neighborhoods.”

Inman cautioned residents who participate in outdoor activities in the evenings near Merced College, such as jogging. Inman said residents need to implement the five “Ds”: Drain standing water; avoid being outdoors at dawn and dusk; dress in light-colored clothing with long sleeves and long pants; and apply DEET when outdoors.

The bike paths in town should also be treated with care because that is where most mosquito-bird interaction takes place, Inman said.

The abatement district started spraying the grounds at Merced College on Monday with mosquito control treatment, and employees applied the first aerial treatment Tuesday night over north Merced. Schultz made sure all staff and students were off campus before the 10 p.m. aerial treatment as a precaution, she said.

It also was the first year the district has treated Bear Creek because of standing water for as long as any employee could remember, Inman said.

Last year was a record-breaking year and was the second-worst year for West Nile virus in the state, Inman said. This year’s drought conditions are reducing the amount of flowing water and increasing the amount of standing water. Though there are fewer mosquitoes out this year, the drought conditions could contribute to a higher infection rates, Inman said.

This story was originally published July 1, 2015 at 6:49 PM with the headline "Mosquitoes at Merced College test positive for West Nile."