FRIDAY, Nov. 3, 2006 (HealthDay News) -- U.S. health officials said Friday they have traced the source of the recent salmonella outbreak to tomatoes served in restaurants.
"We've done standard interviews with people who've become ill with this organism and with well people in the same communities, and we've identified tomatoes eaten in restaurants as the cause of this outbreak," Dr. Christopher Braden, chief of outbreak response and surveillance in the U.S. Centers for Disease Control and Prevention's Foodborne Branch, said during a teleconference.
The outbreak has sickened 183 people in 21 states in the United States, as well as two people in Canada. Twenty-two people have been hospitalized. Most of the cases have been east of the Mississippi River, with the exception of Washington state.
Officials reassured the public that the outbreak is essentially over.
"The bulk of the cases occurred in the last half of September, approximately from Sept. 14 to Oct. 1," Braden said. "The most recent onset of illness was Oct. 13. We've not received reports of illness with onset more recent than that, and for that reason we do believe that this outbreak is not ongoing at this time."
"It did occur in the past, and there is no further risk to the public," Braden added.
Dr. David Acheson, chief medical officer of the Center for Food Safety and Applied Nutrition at the U.S. Food and Drug Administration, said, "All evidence points to the fact that this outbreak is not ongoing. Any tomatoes that could have been implicated would have been destroyed, thrown out or eaten by this time. Therefore, there is no need to issue specific warnings to consumers regarding consumption of tomatoes."
With a specific food identified as the source of the outbreak, the FDA is now doing a "trace back" to identify how the contamination may have happened. "Hopefully, this will lead us back to a farm or group of farms, or area of the country where the tomatoes were grown," Acheson said.
That investigation should take several days, if not a couple of weeks, Acheson added.
The outbreak, which has not caused any fatalities, was first announced late Monday night. It followed the September outbreak of E. coli contamination in fresh, packaged spinach that killed three people and sickened more than 200 in 26 states and one Canadian province.
CDC officials said they first noticed a salmonella problem two weeks ago, via a national computer lab system that looks for patterns and matches in reports of food-borne illness.
The Boston Globe reported that Massachusetts had 51 of the salmonella cases in September, and that there have been no new cases there since the end of that month.
In addition, the Louisville Courier-Journal reported 15 cases in Kentucky, all in September. And the Pennsylvania Health Department was probing at least five cases in five counties in that state; Arkansas was investigating four.
Salmonella is a germ that causes a bacterial disease called salmonellosis. The typical symptoms included diarrhea, fever and stomach pain, which can start up to three days after people become infected. The symptoms usually go away after one week. But some victims do see a doctor or end up in a hospital, because the diarrhea is severe or the infection has affected other organs, according to the CDC.
There are about 2,500 types of salmonella. The type in the new outbreak -- salmonella typhimurium -- is one of the most common, Braden said.
According to the CDC, people can get salmonellosis by eating contaminated food, such as chicken, eggs or produce.
Animals can carry salmonella and pass it in their feces. Therefore, people can also get salmonellosis if they don't wash their hands after touching the feces of animals. Reptiles (such as lizards, snakes and turtles), baby chicks, and ducklings are especially likely to pass salmonellosis to people. Dogs, cats, birds (including pet birds), horses and farm animals can also pass salmonella in their feces.
To learn more about salmonella, visit the CDC.