Outbreak of West Nile Virus in CA – Warning to Outdoor Workers

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LA County, CA – Greater Los Angeles County Vector Control District is reporting an outbreak of West Nile Virus (WVN) in the cities of Carson, Northridge, Reseda, and Signal Hill.

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

So far this year, 10 WNV human cases have been reported in California, two of which were identified by the Los Angeles County Department of Public Health.

According to the CDC, there are no vaccines to prevent or medications to treat WNV in people. Fortunately, most people infected with WNV do not feel sick. About 1 in 5 people who are infected develop a fever and other symptoms. About 1 out of 150 infected people develop a serious, sometimes fatal, illness.

According to NIOSH, outdoor workers may be exposed to WNV whenever mosquitoes are biting.

Outdoor workers at risk include farmers, foresters, landscapers, groundskeepers and gardeners, painters, roofers, pavers, construction workers, laborers, mechanics, and other outdoor workers.

Entomologists and other field workers are also at risk while conducting surveillance and other research outdoors.

In addition to outdoor workers, laboratory workers are at risk of WNV infection if their skin is penetrated or cut while performing necropsies or handling WNV-infected tissues or fluids.

NIOSH recommends protecting workers by taking the following steps (among others):

■ Provide training that describes how WNV is transmitted and reinforces knowledge about the risks of WNV exposure and infection.

■ Stress to workers the importance of reporting all work-related injuries and illnesses in a timely manner.

■ Provide a medical surveillance system that monitors, records, and assesses the symptoms and absenteeism associated with WNV infection.

■ Provide workers with protective clothing (long-sleeved shirts, long pants, and socks) and repellents to use on skin and clothing: — Use repellents containing DEET (more than 20% DEET for longer protection), picaridin, or oil of lemon eucalyptus on both skin and clothing. — Use permethrin on clothing only.

■ Reduce worker exposure to mosquitoes by taking the following steps: — Avoid having workers outdoors when mosquitoes are most active and biting (most often from dusk to dawn).

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.