Health officials on Thursday identified lettuce as the likely source for a hepatitis A outbreak in Los Angeles County and urged residents to thoroughly wash the vegetable before eating it.
At least 60 people have fallen ill from the virus in Los Angeles County over the last three months. Officials are concerned because the outbreak comes after years of declining hepatitis A cases, but they have been unable to link the outbreak to a particular farm or type of lettuce.
There were at least two outbreaks: one in a downtown Los Angeles restaurant in September that affected 13; the other at an event catered by a Hollywood company in October where 19 fell ill. The other cases were scattered.
Officials would not identify the specific locations of the outbreaks, saying there is no ongoing risk at those sites.
"We believe lettuce was the problem in these events," said Dr. Jonathan Fielding, public health director for Los Angeles County.
"This is a problem that deserves real attention, and people eating in a restaurant should ask if the produce is being cleaned carefully."
Fielding added that consumers should wash even salads that are packaged and labeled as washed. Packaged lettuce has been linked to E. coli outbreaks, including a case this fall involving salads packaged by a division of Westlake Village-based Dole Food Co. in Salinas, Calif. The salads sickened more than a dozen people in Minnesota.
Officials had initially observed an increase in hepatitis A in homeless patients in the downtown Los Angeles area, although those numbers are dropping, said Dr. Laurene Mascola, director of the county's acute communicable disease control unit.
The county has observed declining hepatitis A rates since 1999, when health officials began advising that children be vaccinated against the disease.
Mascola said her office is still analyzing hepatitis A cases for November, but the reported cases appear to be going down. She has so far confirmed two cases in November and is reviewing 30 to 40 other reported cases, Mascola said.
Outbreaks are hard to track, because the disease has a two- to eight-week incubation period. Infected people start showing symptoms after a month.
Symptoms include fever, chills, aches, fatigue, nausea, vomiting, abdominal cramps, dark urine and jaundice. The Centers for Disease Control and Prevention reported 7,653 acute cases in the United States in 2003. Most infected people recover with medical attention, but hepatitis A kills about 100 each year nationally.
The nation's largest outbreak occurred in 2003, when about 600 people were sickened and four died after eating at Chi-Chi's restaurant outside Pittsburgh. That outbreak was linked to tainted green onions. The Food and Drug Administration responded by halting imports of green onions from Mexico.
Los Angeles County's last hepatitis A outbreak stemming from raw food was in 1996, also involving green onions, Mascola said.
Two years ago, about 30 people were sickened by E. coli-contaminated lettuce in Orange and San Diego counties. That outbreak was traced to a Ventura County packing plant.
State health officials are working to track down the source of the contaminated lettuce in this year's outbreak, Mascola said.
In the meantime, the best thing salad-lovers can do — short of boiling their salad and getting a hepatitis A vaccination — is to wash their lettuce, Mascola said.
"Anything that's on the ground, that's not cooked, you can get sick with," Mascola said. "Eating food that's not cooked can always have some risks associated with it."
With lettuce, some people "throw it in a colander, and swish water around — that's not going to be effective," Mascola said.
A better idea, officials said, is to rinse the lettuce in cool water. Using a brush may also be more effective, Fielding said.
Bob Sandelman, who runs a San Clemente-based research firm on the restaurant industry, said it is unlikely that lettuce sales would be affected unless officials tie an outbreak to certain restaurants or a major distributor.
"If it's something that's more widespread … I can see where that would cause some consumers to avoid salad bars or to avoid other menu items that have lettuce in them," he said.