L.A Times: Upsurge of West Nile virus linked to foreclosures, study finds

So far, the state has reported a total of 355 cases, with the most – 126 cases – occurring in Los Angeles County.

Scientist say cases soared in Bakersfield last year largely because of mosquitoes breeding in abandoned swimming pools. One of the nations worst-hit cities for foreclosures in 2007 — Bakersfield — became an epicenter of West Nile virus that year largely because of mosquitoes breeding in abandoned swimming pools, UC Davis and Kern County scientist reported Thursday.

Since the mortgage crisis began, public health officials throughout the state, particularly in Southern California, have complained that neglected pools are contributing to West Nile infections

The Central Valley city had 140 diagnosed cases, up from 51 in 2006, or a 275% increase. Over the same period, mortgage delinquency notices went up by 300 %

Other factors played a role. Unusually mild weather allowed virus-carrying mosquitoes to survive the winter, the study found. And mosquitoes became active earlier and multiplied more rapidly in an exceptionally warm spring and summer.

By the time public health officials noticed the first human case, the virus had exploded.

Once we had one human case, it was almost like popcorn after that,” said Dr. Claudia Jonah, Kern County’s interim health officer. “In a year in which we should not have had any cases, we had the most in the nation.”

The exceptionally dry winter and spring had initially been expected to cut down on the number of mosquitoes. But, in fact, the drought contributed to the problem, the study found, drawing birds to the suburbs in search of water. The birds found thousands of stagnant pools, teaming with newly hatched mosquitoes.

West Nile is primarily a bird disease, transmitted among birds – and to humans – by mosquitoes. Most people who are infected by the virus do not become ill. But about 20% of those infected develop flu-like symptoms, and about one in 150 develop the most serious form of the disease, which can cause encephalitis, meningitis and death.