West Nile flapping its way north

Whereas in years past health officials speculated that The City would be spared the West Nile virus, this year they are warning San Franciscans to take preventative measures since the virus is due to arrive in the area within the next four weeks.

"We will have West Nile here," said Rajiv Bhatia, director of environmental and occupational health at San Francisco's Department of Public Health.

It is just a question of time, agreed health officials. Vicki Kramer, chief of the vector-borne disease section of the California Department of Health, said that between the northerly flight pattern of infected birds from Southern California and short-hopping birds discovered infected in San Jose in late June, San Francisco residents can expect to deal with the sometimes-deadly disease within a month.

The virus, common in Africa and Asia, is transmitted by mosquitoes and spread by birds. Although infected birds eventually die, the mosquitoes that feed on these infected birds can spread the disease to humans or other animals they bite.

The disease has already wreaked more havoc in California than it did in 2003. Whereas only three infections were reported in the state last year, so far at least 28 cases have been reported to the CHC. The virus took its first human life in California on June 24, when an Orange County man died. And it penetrated Northern California on June 28, when a dead crow tested positive in San Jose.

The flight patterns of migratory birds explain this year's burgeoning number of cases, said Bhatia, who said infected birds have gradually made their way to California from the East Coast.

Despite speculation of previous years that San Francisco would be spared the disease due to its cooler climate, Bhatia said it seems The City will be no exception.

"We just don't know," he said. "Our chances of avoiding infection could be better in San Francisco because it is cooler, or it could be worse because it is wetter here. And while we have less wildlife than surrounding areas, we also have a higher population density."

Because of these unknowns, District 11 Supervisor Gerardo Sandoval submitted a letter of inquiry to Tuesday's Board of Supervisors meeting asking the Department of Public Health to report back within two weeks about The City's plan to combat the spread of the virus.

San Francisco County is the only county in the Bay Area that does not have a dedicated mosquito surveillance program according to the California Department of Health.

"Mosquitoes doen't respect county lines," said Sandoval. "And we don't have a real plan in place for mosquito abatement."