California health officials warned Tuesday that the risk of contracting West Nile virus from mosquito bites is the highest in four years, Xinhua reported. So far this year, 566 dead birds and 316 mosquito samples in Southern California have tested positive for West Nile, according to the California Health Department. Health officials were worried about a possible repeat of cases such as what happened in 2004 when Southern California experienced710 human West Nile virus cases with 21 fatalities, the department said. Robert Cummings, director of scientific services for Orange County Vector Control, said officials were gearing up to launch a public education radio campaign that will begin in mid-August, when the number of infections usually increases. "We're seeing a trend almost two times higher than we've seen in the past years, and every bit as high and in some cases higher than 2004," Cummings said. "Also our dead bird counts show that in excess of 70 percent of the dead birds are coming back positive for as having been exposed to and dying from West Nile virus." Cummings echoed earlier concerns that mosquitoes could be breeding in pools left with water when families move away. "Definitely what we've noted is a disturbing trend because of this home foreclosure crisis, the number of neglected swimming pools occurring in people's backyards," Cummings said. "And we see thousands throughout Southern California now and many of these are breeding mosquitoes." About 80 percent of human cases of West Nile virus infection usually occur from August through October, and officials said those cases seen so far may be only the beginning of a large number of future cases in Southern California. So far, 70 percent of the West Nile victims this year in Southern California have contracted the more serious, neurological form of the disease, called West Nile neuroinvasive disease, officials said. The virus has attacked people between the ages of six months and 96 years of age, officials said.
