WEDNESDAY, June 11, 2008 (HealthDay News) -- U.S. health officials said Wednesday they are zeroing in on a source for the recent outbreak of salmonella from contaminated tomatoes.
"The question is where specifically did these tomatoes come from," Dr. David Acheson, associate commissioner for foods at the U.S. Food and Drug Administration said during a teleconference Wednesday. "We're getting very close, but at this point, today, we don't know for sure where they did come from."
Parts of Florida are still under investigation, although northern Florida, which was not harvesting at the time the outbreaks began, has been ruled out as a source for the contamination.
Several other states have been excluded but, beyond that, Acheson said, "anywhere else is essentially open for question in terms of whether that is the source."
The number of people affected by the outbreak remains essentially flat, with 167 people from 17 states infected and 23 people hospitalized. The death of a man in Texas who died is still being investigated, Dr. Ian Williams, chief of the OutbreakNet Team at the U.S. Centers for Disease Control and Prevention, said during the teleconference. The man had cancer and consumed pico de gallo, which is made with tomatoes.
The actual number of people infected is likely to be many more, Williams said. "Many people with salmonella infection don't have stool specimen tests," he said.
On Tuesday, the warning about salmonella-contaminated tomatoes was expanded to include the entire country.
The outbreak was first identified in May with a cluster of approximately 20 people in New Mexico infected with salmonella which had the same genetic footprint. Another cluster was then identified in Texas.
Officials were then able to trace the outbreak to contaminated tomatoes.
The particular type of salmonella involved, Salmonella Saintpaul, is virulent and relatively rare, accounting for only about 400 reported cases annually in the United States, Williams said.
Acheson reiterated that the outbreak of salmonella contamination seems to be linked with certain types of raw, red tomatoes and products containing these tomatoes. In particular, the agency said, raw, red plum tomatoes, raw, red Roma tomatoes and raw, round red tomatoes should be avoided at this time.
Cherry tomatoes, grape tomatoes, homegrown tomatoes and tomatoes sold with the vine still attached appear to be safe. But all tomatoes should be washed before eating, officials advised.
And, until a source for the outbreak is identified, consumers need to employ a little detective work before consuming tomatoes or tomato products.
"The best advice right now is to be extremely careful in trying to find out exactly where the tomatoes they're purchasing are from," said Tony Corbo, legislative representative for Food & Water Watch, a Washington, D.C.-based nonprofit consumer group that works to ensure clean water and safe food.
"The other problem with tomatoes is that they have shown up in restaurants and in salsa. So, maybe for the time being, consumers should stay away from anything that is processed," Corbo said.
On Tuesday, FDA officials also recommended that retailers, restaurants and other food service operators not offer raw, red Roma, raw, red plum, and raw, red round tomatoes unless they are from sources that have not been associated with the outbreak. If unsure of where tomatoes were grown or harvested, consumers are encouraged to contact the store where the tomato purchase was made, the agency said.
Several large fast food, restaurant and grocery chains, including McDonald's, Wal-Mart, Burger King, Kroger and Outback Steakhouse, have voluntarily withdrawn red plum, red Roma or round red tomatoes not grown in certain states and countries. Also, the Los Angeles Unified School District has suspended serving raw tomatoes, the AP said.
The FDA recommends consuming raw, red plum, raw, red Roma or raw, red round tomatoes only if grown and harvested from these areas: Alabama, Arkansas, California, Georgia, Hawaii, Louisiana, Maine, Maryland, Minnesota, Mississippi, New York, Nebraska, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Texas, West Virginia, Belgium, Canada, the Dominican Republic, Guatemala, Israel, the Netherlands and Puerto Rico.
"The tomatoes that are being grown at home or in local gardens in the area should be fine," said Sharon Wilkerson, acting dean of the Texas A&M Health Science Center College of Nursing in College Station. "The main thing is to really wash things, and [tomatoes] should be washed before removing the hull or stem. Tomatoes you see in stores that are multiples on stems are usually grown in hot houses, and they should be OK."
States reporting illnesses linked to the outbreak include: Arizona, California, Colorado, Connecticut, Idaho, Illinois, Indiana, Kansas, New Mexico, Oklahoma, Oregon, Texas, Utah, Virginia, Washington, and Wisconsin, the FDA said.
Salmonella is a bacteria that can cause bloody diarrhea in humans. Some 40,000 cases of salmonellosis are reported in the United States each year, although the CDC estimates that because milder cases are not diagnosed or reported, the actual number of infections may be 30 or more times greater. Approximately 600 people die each year after being infected.
Tomatoes can be a particular problem, Williams said, with 13 multi-state outbreaks of salmonella linked to tomatoes since 1990.
Acheson denied that the food-safety system is deteriorating, pointing out, instead, that technology for detection is improving at the same time consumers are becoming more informed. "The situation is not getting worse but this is a reactive mode we're in," he said. "Where we're trying to focus is prevention. We are working with the states of Florida and Virginia to understand better how to prevent contamination of tomatoes with salmonella." Other initiatives are also under way, he said.
Visit the U.S. Centers for Disease Control and Prevention for more on the current salmonella outbreak.