The Greater Los Angeles County Vector Control District said Friday 11 additional mosquito samples positive for West Nile virus have turned up, bringing the number of samples positive for the virus within the district’s service area to 25 this year.

Positive samples were collected in four new areas: Montebello, Santa Fe Springs, South Whittier and Woodland Hills, the district said in a statement.

It added that mosquito control is a shared responsibility and residents must take an active role in reducing the threat of WNV in their neighborhoods by taking the following steps:

– Eliminate standing water in clogged rain gutters, rain barrels, discarded tires, buckets, watering troughs or anything that holds water for more than a week;

– Ensure that swimming pools, spas, and ponds are properly maintained;

– Change the water in pet dishes, birdbaths and other small containers weekly;

– Request mosquitofish from your local vector control district for placement in ornamental ponds;

– Wear EPA-recommended insect repellent when outdoors where mosquitoes may be present;

– Report neglected (green) swimming pools in your neighborhood to your vector control district.

West Nile virus is endemic in Los Angeles County, and the summer heat can increase virus activity and mosquito populations, according to the statement.

So far this year, 57 WNV human cases have been reported in California, four of which were identified by the Los Angeles County Department of Public Health.

West Nile virus is a leading cause of severe infections of the nervous system among adults older than age 50 in Los Angeles County. WNV is transmitted to people and animals through the bite of an infected mosquito. There is no cure for WNV.

One in five persons infected with the virus will exhibit symptoms, which can include fever, headache, body aches, nausea, or a skin rash. These symptoms can last for several days to months. One in 150 people infected with the virus will require hospitalization. Severe symptoms include high fever, muscle weakness, neck stiffness, coma, paralysis, and possibly death.

The communities where positive samples were found in the Los Angeles region this year, according to the district, included Bellflower, Canoga Park, Carson, Cerritos, Granada Hills, La Mirada, Lakewood, Long Beach, Montebello, Northridge, Reseda, Santa Fe Springs, Signall Hill, South Whittier, West Hills, Woodland Hills, and Winnetka.

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