California's outbreak of hepatitis A, already the nation's second largest in the last 20 years, could continue for many months, even years, warned Monique Foster, MD, a medical epidemiologist with the Division of Viral Hepatitis at CDC. At least 569 people have been infected and 17 have died of the virus since November in San Diego, Santa Cruz, and Los Angeles counties, where local outbreaks have been declared. Many areas in the state are beginning to offer vaccines to their homeless populations, which are considered most at risk. Doctors say that people with hepatitis A could travel and unknowingly infect people in a new community, creating more outbreaks. The only outbreak of hepatitis A in the last 20 years bigger than California's occurred in Pennsylvania in 2003, when more than 900 people were infected after eating contaminated green onions at a restaurant. California's outbreak, however, is spreading from person to person, mostly among the homeless community. Eric McDonald, MD, of the San Diego County Health Department, said county health workers have vaccinated 57,000 people in the county who are either homeless, drug users, or people in close contact with either group. "The general population—if you're not in one of those specific risk groups—is at very low risk, and we're not recommending vaccinations," he said.