Air Team Puts West Nile Virus in Sights

Stepping up efforts to combat West Nile virus, San Gabriel Valley vector control officials on Tuesday enlisted the help of the Pasadena Police Department’s air support team to help locate dirty swimming pools attractive to mosquitoes.

As part of “Operation Dirty Water,” police and vector control technicians conducted a helicopter survey of the area to spot pools filled with murky, green water that could be breeding grounds. The four-hour search turned up 100 algae-filled pools.

“This is out of control,” said Lt. Bob Mulhall, who piloted a Bell Jet Ranger helicopter used in the survey. “They really jump out at you when you see one.”

The unusually wet winter has health officials concerned about the potential for the spread of West Nile disease, which has claimed the lives of 28 people in California since July.

So far this year, one human case has been reported in Los Angeles County. The victim, who is believed to have contracted the virus last year, is recovering.

In addition, dead birds have tested positive for the virus in Los Angeles, San Bernardino and Orange counties and 16 others statewide. Mosquitoes that feed on the birds pass on the virus to humans.

Most people who become infected experience mild flu-like symptoms, including headaches, fever, rash and general weakness. Less than 1% of cases are fatal.

To guard against the spread of the virus, Pasadena police and the San Gabriel Valley Mosquito and Vector Control District teamed up, using two helicopters from the police department’s Foothill Air Support Team to find so-called green pools.

During the survey, vector control technicians used a global positioning satellite system and tax assessor records to spot and identify private and commercial properties with stagnant pools.

Under the California health and safety code it is illegal for a homeowner to maintain a breeding source for mosquitoes, said Kelly Middleton, spokeswoman for the vector control district.

“Our service is to go out and help residents control mosquito problems,” Middleton said. “If they work cooperatively with us, no fee is asked.”

If a search warrant is needed, a homeowner could be fined $1,000 a day for not complying with state regulations, she said.

Green pools attract mosquitoes that lay their eggs in the stagnant water, providing a food source for larvae. Thousands of mosquitoes can form in less than two weeks if a green pool is not treated. There are more than 2,300 known green pools in the San Gabriel Valley, Middleton said.

In the past, vector control technicians relied heavily on a central database of mosquito reports as well as anonymous tips on poorly maintained pools or other infested bodies of water. Other breeding grounds include old tires, potted plants, sewers and rain gutters.