Cases of West Nile Expected to Expand

The Riverside County Board of Supervisors on Monday received a warning about West Nile virus, with health officials briefing the board about the increasing reach of the potentially deadly illness.

“We know West Nile virus is here to stay,” said Susan Mackintosh, assistant public health officer. “We can expect more human cases this year, and unfortunately ... we can expect some deaths” nationally.

Most people infected by West Nile virus have no symptoms. Twenty percent develop mild symptoms, such as fever and rash, but 1% can develop more severe symptoms that can lead to coma, convulsions and death.

The virus, which is carried in birds and spread by mosquitoes, was first seen on the East Coast in 1999. California had three cases last year attributed to infections acquired locally, the first of which was a Moreno Valley man who worked near the Santa Ana River, a mosquito breeding spot.

This year, California already has had seven cases, all in San Bernardino County.

Mackintosh noted that the disease could hit hard locally. Testing of dead birds reveals a growing presence. In 2003, only 1% of 8,650 dead birds tested in Riverside County were found to have the virus; this year, 24% of 856 tested were infected.

She urged residents to protect themselves by draining standing water on their property so mosquitoes can’t breed, avoiding the outdoors at dawn and dusk when mosquitoes are most active, wearing protective clothing, and using an insect repellent that contains DEET.