WASHINGTON - Investigators are seeing more signs that the salmonella outbreak blamed on tomatoes might have been caused by tainted jalapeno peppers and have begun collecting samples from restaurants and from the homes of those who have been sickened, according to health officials involved in the probe.
New interviews with those who became infected found that many had eaten jalapeno peppers, often in salsa served with Mexican food, according to two state health officials. So far, none of the jalapenos taken from restaurants and from the homes of those who became ill have tested positive for Salmonella saintpaul.
Echoing federal officials, who said this week that tomatoes remain the prime suspect, the health officials said that tomatoes cannot be ruled out as the cause of the outbreak. Investigators have been collecting samples of another possible suspect, cilantro, though the herb is less likely to be the source, said the officials, who spoke on condition of anonymity because the investigation is continuing.
The outbreak, which began 12 weeks ago, is believed to be the largest of its kind, and new cases continue to emerge. It has sickened more than 920 people across the country, up from 756 one week ago, and sent more than 110 to the hospital. In Maryland, 29 people have been confirmed to have the illness, which can cause nausea, vomiting and diarrhea, and, in severe cases, death.
In late May, investigators began focusing on tomatoes as the probable source of the outbreak. But they expanded their investigation last week, asking 100 labs around the country to help, because the number of new infections kept growing despite the short shelf life of tomatoes and warnings to avoid certain varieties.
Delays in pinpointing the cause of the outbreak have frustrated consumers, angered the produce industry and prompted members of Congress to call for food safety reforms.
"How sad is that? We can't even really figure out what it is," said Rep. Diana DeGette, a Colorado Democrat who has proposed food tracking and mandatory recall measures. "We've had the same problem with other products in past years, which shows us the food safety system in this country is outdated and underfunded."
Chile peppers are largely grown in Mexico, Central America and warm weather U.S. states such as Florida. Food-safety specialists said jalapenos are not a common cause of bacterial outbreaks and counseled caution about rushing to judgment that the peppers are responsible for this one.
Contaminated green chile peppers in Colorado sickened 80 people in 1998 and 60 in 2001, according to the Center for Science in the Public Interest, which tracks food-borne illnesses. Neither outbreak involved salmonella bacteria.
A likely source of jalepeno contamination is the water used to irrigate plants or wash peppers after they're picked, said Robert B. Gravani, a food science professor at Cornell University.
One health official involved in the investigation said "loose ends" are keeping tomatoes under suspicion, but the official said they could be accounted for easily. The official said evidence is "piling up" that indicates that jalapenos are to blame.
"There's certainly no shred of doubt in my mind," the official said.
Another health official was more cautious, saying that the evidence is pointing to peppers but that there is not yet enough information to rule out tomatoes. The official said the Food and Drug Administration is enlisting more labs in the investigation so it can test jalapenos, tomatoes and cilantro more quickly.
Both officials played down the likelihood that cilantro is to blame, saying the evidence for that is thin.
Health officials fear that an acknowledgment that the outbreak was not caused by tomatoes could undermine confidence in the public health system. Officials are especially worried that it could reduce support for using statistical analysis of interviews with infected people to justify warnings and recalls, despite many previous successes, because officials decided to issue the tomato warning without waiting to find one that was contaminated.
Tomato industry groups have criticized the use of statistical analysis and say that government health officials should wait until they find a contaminated product before taking serious actions such as recalls. But government officials say that delaying a warning could cause serious harm to public health, because more people could become sick without an early alert.
The tomato industry estimates that it has lost $100 million since the June 10 warning.
"What makes it so pathetic is there has been nothing found," said Bob Spencer, co-owner of West Coast Tomato, which was forced to stop harvesting its fields in Florida and let tomatoes rot in company warehouses.
Liberal interest groups, leading trade associations and congressional critics say the failure to find the outbreak's source, after seven weeks of trying, points up the need for better food tracking systems. They contend that better labeling could quickly lead investigators to a farm that harvested suspicious produce.
Some growers and suppliers have such tracking systems in place. Critics say the FDA should require the tracking systems, which provide detailed information about the source and distribution of produce.
"There is a lot of frustration that the FDA cannot tell us where the tomatoes are from or even whether tomatoes are the cause," said Caroline Smith DeWaal, food safety director at the Center for Science in the Public Interest.