Weekly WNV and Invasive Aedes Mosquito Update 6/20/16

Los Angeles, Calif. –  The Greater Los Angeles County Vector Control District (GLACVCD) cautions Santa Clarita Valley residents to take extra precautions against West Nile virus (WNV) now to reduce the threat as the summer progresses. Early-season indications predict the Valley may see increased activity this year. This past week, GLACVCD confirmed additional WNV-positive mosquito samples from Granada Hills and West Hills, and WNV-positive crows were collected from the cities of Santa Clarita and Valencia.

“The majority of West Nile virus activity detected this spring has been from the Santa Clarita Valley” reports Susanne Kluh, the District’s director of scientific technical services. “We need residents in the Valley to step up and help us reduce the risk of disease transmission,” added Kluh.

Improperly maintained swimming or wading pools can breed thousands of mosquitoes per day. Ponds, fountains, rain barrels, and other containers will contribute large numbers of mosquitoes to a neighborhood, and directly increase the risk of WNV transmission to people through the summer. Higher temperatures speed up both the mosquito life cycle and replication of the virus in mosquitoes and wild birds.

The time to take action is NOW. Eliminate all standing water sources from properties, and report mosquito problems, inoperable swimming pools/ponds to the District promptly.

To date,the GLACVCD has confirmed West Nile virus in nine mosquito samples and 10 dead birds.

See the Stats: West Nile Virus

Vector control advises residents to take the necessary precautions to avoid mosquito bites by using insect repellent. Effective repellents contain EPA-registered active ingredients such as DEET, Picaridin, oil of lemon eucalyptus, or IR3535. Residents should also dump and drain any standing water around the home. This prevents mosquitoes from laying their eggs in any container that can hold stagnant water.

West Nile virus is transmitted to people and animals through the bite of an infected mosquito. There is no cure for West Nile virus. One in five persons infected with West Nile virus will exhibit symptoms. Symptoms usually occur between five and 15 days, and can include fever, headache, body aches, nausea, or a skin rash. These symptoms can last for several weeks 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.

Invasive Aedes Mosquitoes Update

The District’s Aedes control teams are aggressively surveying neighborhoods and following up on reports of day-biting mosquitoes. Aedes mosquitoes continue to be a problem in several cities, but the situation has improved in others. The cities of Commerce, South El Monte, as well as east Los Angeles, and Silver Lake are reporting biting activity. As these mosquitoes do not travel far from their water source, residents in these communities are encouraged to work with the District and their neighbors to find and remove problem breeding sites in the neighborhood.

There is good news for residents of Atwater Village, La Canada Flintridge, and Highland Park. Follow-up inspections have detected no additional Aedes mosquitoes after aggressive actions were taken against small infestations found in these communities last fall. The District encourages residents to keep up the good work, and report any new mosquito issues promptly.

“Removing containers and other sources containing water or mosquito eggs is critical for controlling these species. If you don’t get rid of the eggs, the mosquitoes will come back,” noted Kelly Middleton, community affairs director for the District. Aedes eggs are extremely tiny and hard to differentiate from dirt. To be safe, all containers should be stored inverted and in a covered area, or disposed of in sealed trash bags.

Invasive black-and-white mosquitoes remain a concern for vector control officials as summer progresses. Aedes mosquitoes are now widespread in many California communities.

Aedes mosquitoes are invasive to Los Angeles County and are efficient at transmitting (vectoring) Zika, chikungunya and dengue fever viruses. These viruses are currently not transmitting from mosquitoes to people in L.A. County. However, the importance of avoiding mosquito bites remains the same with Aedes mosquitoes, just as it does with common species that carry West Nile virus.

Read more about Aedes mosquitoes here.

If residents are still experiencing mosquito problems even after dumping and draining all standing water, they can receive help from the Greater Los Angeles County Vector Control District at (562) 944-9656 or visit www.ReportMosquitoes.org.