West Nile Virus Detected Throughout San Gabriel Valley, As Close as Altadena, But Not in Pasadena

While Pasadena remains free of West Nile Virus (WNV), according to Pasadena Health Director Michael Johnson, the virus has been detected throughout the San Gabriel Valley, with one WNV-positive dead bird reported next door in Altadena.

Indeed, the San Gabriel Valley Mosquito and Vector Control District’s surveillance program has located 23 mosquito samples in Arcadia, Azusa, Pomona, San Gabriel and West Covina that tested positive for WNV and five dead birds with WNV found in Altadena, Monrovia, Temple City and Glendora.

In Pasadena, as of July 26, Johnson says there have been no reported human cases of mosquito-borne diseases, including Zika, West Nile, Chikungunya and Dengue fever this year. WNV, Chikungunya and Dengue are not contagious from person to person and are spread through mosquito bites.

“We don’t have anything necessarily unusual going on in Pasadena,” he told Pasadena Now. “I think what we’re seeing is across the region and I’m counting really sort of the whole state of California. We’re seeing increased numbers of West Nile in these indicator flocks.”

Johnson said there have been a total of 22 cases of human WNV across California lately, including four in Los Angeles county.

Since its first detection in California in 2003, WNV has infected more than 5,588 people and caused 229 deaths statewide, according to the California Department of Public Health. The virus is now endemic in California and presents a public health risk every year.

Officials say it is critical that residents remove all standing water on their property to prevent mosquito production.

In Pasadena, Johnson says Public Health staff continue to monitor reports of mosquito breeding and make sure suspect areas are treated.

“When we find that there might be issues where there’s standing water, and specifically if we see that there’s actual mosquito breeding on them, we’ll treat that with a larvicide, which is basically an oil that suffocates the mosquito larvae while they’re on standing water,” Johnson said. “Also, we can go in everybody’s backyard so the message that we want to get out is people need to look at their properties and make sure there’s no standing water.”

Mosquitoes tend to lay their eggs in stagnant water such as neglected pools, buckets, miscellaneous containers, puddles, and ponds. Eggs can hatch and develop into biting adults in four to seven days.

Pasadena Public Health Officer Dr. Ying-Ying Goh offers the following tips to avoid WNV:

Around the home:

• Eliminate all outdoor sources of standing water
• Use a scrub brush and hot soapy water to clean unused, outdoor containers you intend to keep, such as tires, buckets and flower pots, that have had standing water in them; then turn over those unused containers to prevent new standing water from accumulating inside
• Keep swimming pools clean and water circulating; keep filter equipment in good repair
• Check for larvae in ornamental water sources and treat as necessary with “mosquito dunks” available from hardware stores
• Change bird bath water every five days
• Keep ornamental and fish ponds stocked with mosquito fish; use a pump to keep water moving
• Screen and cover rain barrels

At home and when traveling:

Wear repellants containing DEET or oil of lemon eucalyptus

• Wear repellants containing DEET or oil of lemon eucalyptus
• If possible, wear long-sleeved shirts and long pants when outdoors, as conditions permit
• Regularly check yourself for bugs and bites if outdoors for long periods
• Make sure your hotel or lodging has air conditioning and window screens
• Check window screens for holes or tears

For more on mosquito-borne diseases, visit www.cdc.gov/features/StopMosquitoes.

For updates from the City of Pasadena, visit www.cityofpasadena.net and follow the city on Twitter @PasadenaGov (www.twitter.com/pasadenagov), on Instagram @PasadenaGov (www.instagram.com/pasadenagov) and on Facebook at www.facebook.com/cityofpasadena. The city’s YouTube channel is at www.youtube.com/pasadenagov.

Citizens can call the Citizen Service Center, 7:30 a.m. to 5 p.m., Monday through Friday at (626) 744-7311.

The San Gabriel Valley Mosquito and Vector Control District can be reached at (626) 814-9466 or online at www.SGVmosquito.org.

Dead birds should be reported to the WNV hotline at (877) WNV-BIRD or (877) 968-2473, or online at www.westnile.ca.gov.