3 West Nile virus cases reported in Riverside County. How to stay safe

It’s early September, which means Riverside County is just over halfway through its typical West Nile virus season.

So far, three human cases of West Nile have been reported in the county, all in people living in Inland Empire communities on the county’s west side. The county's disease expert says that’s a fairly typical number of cases for this point in the year. No human cases have been reported in the Coachella Valley.

Here is what residents should know about this year’s West Nile virus season and how to keep themselves safe.

What is the West Nile situation in the Coachella Valley?

Barbara Cole, Riverside County Public Health’s disease control director, said West Nile is well established in mosquito populations and it is expected that there will be a few human cases each year. While the number varies from year-to-year, she said three cases at this point in the year is “pretty average” and not cause for unusual concern.

The Coachella Valley Mosquito and Vector Control District reports that West Nile has been found in mosquitoes in several communities in the central and eastern Coachella Valleys so far this season, including Rancho Mirage, Palm Desert, Indian Wells, La Quinta, Indio, Coachella, Mecca and Thermal. Data from the control district website shows the number of positive mosquitoes in the valley shot up far above where it has typically been in recent years before stabilizing at around average levels in August. Recent data shows that the highest number of positive mosquitoes has been concentrated on the eastern end of the valley near the Salton Sea.

What is the situation in the rest of Southern California?

California Department of Public Health data shows Riverside, San Bernardino and Kern counties are the only counties in the region where human West Nile cases have been reported this year, with Riverside County reporting the most. However, West Nile has been found in mosquitoes in most Southern California counties this season. Statewide, 27 human cases have been reported along with nearly 1,400 positive mosquitoes. Three people have died.

People can check the latest statewide mosquito numbers at Westnile.ca.gov .

When is the West Nile season?

The season typically starts in April or May and goes through the end of October and sometimes into November, Cole said. She said it is hard to determine if the latter part of the season could bring more cases than the county has seen so far. When temperatures get colder in the winter, mosquitos enter various hibernation-like states.

Where were the cases in Riverside County?

Cole said two of the people who tested positive lived in or near Corona, although they are not aware of any linkages between them. The third case was in Perris.

She said all are considered individual cases that are not part of any linked clusters and all of the people either have recovered or are recovering.

How does West Nile spread?

The disease can only be spread to humans from mosquitoes and not from other humans. The CDC says that mosquitoes become infected when they eat infected birds and then spread it to people and other animals by biting them.

How can people stay safe?

Cole said the best way to protect yourself from West Nile is to take steps to reduce your likelihood of being bit by a mosquito. The standard precautions include limiting or avoiding being outdoors between dusk and dawn, which is when mosquitoes are most active.

If one is spending time outside, she said it is recommended to wear long-sleeve shirts, pants or other clothing that covers the skin and apply mosquito repellent on skin that is exposed. She said people should also avoid standing water.

What are the symptoms of West Nile?

About 80% of people who become infected with West Nile never develop symptoms, according to the CDC . The remaining 20% develop a fever and exhibit symptoms such as headache, body aches, joint pains, vomiting, diarrhea and rash.

About 1 in 150 develop a severe illness that can impact the nervous system, brain and spinal cord. About 10% of the people who develop serious symptoms die from the disease. Cole said people who have chronic health issues and are exhibiting any symptoms of West Nile should immediately contact a doctor.

Paul Albani-Burgio covers growth, development and business in the Coachella Valley. Follow him on Twitter at @albaniburgiop and email him at paul.albani-burgio@desertsun.com .

This article originally appeared on Palm Springs Desert Sun: 3 West Nile virus cases reported in Riverside County. How to stay safe