Multistate Outbreak of Salmonella Saintpaul Infections Linked to Raw Produce
Posted July 9, 2008
This outbreak appears to be over. However, Salmonella is an important cause of human illness in the United States. More information about Salmonella, and steps people can take to reduce their risk of infection, can be found on the CDC Salmonella Web Page.
Cases infected with the outbreak strain of Salmonella Saintpaul, United States, by state
Incidence of cases of infection with the outbreak strain of Salmonella Saintpaul, United States, by state
CDC is collaborating with public health officials in many states, the Indian Health Service, and the U.S. Food and Drug Administration (FDA) to investigate an ongoing multi-state outbreak of human Salmonella serotype Saintpaul infections. An initial epidemiologic investigation in New Mexico and Texas comparing foods eaten by persons who were ill in May to foods eaten by well persons identified consumption of raw tomatoes as strongly linked to illness. A similar but much larger, nationwide study comparing persons who were ill in June to well persons found that ill persons were more likely to have recently consumed raw tomatoes, fresh jalapeño peppers, and fresh cilantro. These items were commonly, though not always, consumed together, so that study could not determine which item(s) caused the illnesses.
Recently, many clusters of illnesses have been identified in several states among persons who ate at restaurants. Most clusters involve fewer than 5 ill persons. Three larger clusters have been intensively investigated. In one, illnesses were linked to consumption of an item containing fresh tomatoes and fresh jalapeño peppers. In the other two, illnesses were linked to an item containing fresh jalapeño peppers and no other of the suspect items. The accumulated data from all investigations indicate that jalapeño peppers caused some illnesses but that they do not explain all illnesses. Raw tomatoes, fresh serrano peppers, and fresh cilantro also remain under investigation. Investigators from many agencies are collaborating to track the source of the implicated peppers and other produce items.
Since April, 1017 persons infected with Salmonella Saintpaul with the same genetic fingerprint have been identified in 41 states, the District of Columbia, and Canada. These were identified because clinical laboratories in all states send Salmonella strains from ill persons to their State public health laboratory for characterization. No new states report ill persons. The number of ill persons identified in each state is as follows: Alabama (2 persons), Arkansas (14), Arizona (49), California (9), Colorado (13), Connecticut (4), Florida (2), Georgia (24), Idaho (4), Illinois (100), Indiana (14), Iowa (2), Kansas (17), Kentucky (1), Louisiana (1), Maine (1), Maryland (29), Massachusetts (25), Michigan (8), Minnesota (15), Missouri (12), New Hampshire (4), Nevada (11), New Jersey (9), New Mexico (98), New York (28), North Carolina (10), Ohio (8), Oklahoma (24), Oregon (10), Pennsylvania (11), Rhode Island (3), South Carolina (2), Tennessee (8), Texas (384), Utah (2), Virginia (29), Vermont (2), Washington (11), West Virginia (1), Wisconsin (11), and the District of Columbia (1). Four ill persons are reported from Canada; three appear to have been infected while traveling in the United States, and one illness remains under investigation.
Among the 744 persons with information available, illnesses began between April 10 and June 26, 2008, including 300 who became ill on June 1 or later. Many steps must occur between a person becoming ill and the determination that the illness was caused by the outbreak strain of Salmonella; these steps take an average of 2-3 weeks. Therefore, an illness reported today may have begun 2-3 weeks ago. Patients range in age from <1 to 99 years; 50% are female. The rate of illness is highest among persons 20 to 29 years old; the rate of illness is lowest in children 10 to 19 years old and in persons 80 or more years old. At least 203 persons were hospitalized. One death in a man in Texas in his eighties has been associated with this outbreak. In addition, a man in his sixties who died in Texas from cancer had an infection with the outbreak strain of Salmonella Saintpaul at the time of his death; the infection may have contributed to his death.
Only 6 persons infected with this strain of Salmonella Saintpaul were identified in the country during April through June of 2007. The previous rarity of this strain and the distribution of illnesses in all U.S. regions suggest that the implicated food is distributed throughout much of the country. Because many persons with Salmonella illness do not have a stool specimen tested, it is likely that many more illnesses have occurred than those reported. Some of these unreported illnesses may be in states that are not on today’s map.
Health officials have worked continuously since late May to investigate this outbreak. CDC has sent 20 people to the field to work with other public health officials. The investigation is complex and difficult. One difficult aspect is that people often have difficulty remembering exactly what foods they ate, and remembering specific ingredients in those foods is even more difficult. Although laboratory testing of foods might help identify the source, perishable foods that were consumed by ill persons are often not available to test. When food items are mixed together and consumed in the same dish, all the items may be statistically linked to illness. In that case, determining by statistical means which item caused the illness can be difficult or impossible. Tracing suspect produce items back to processors and growers is an integral part of the effort to identify a single source and a possible means of contamination.
Clinical features of Salmonella Infection
Most persons infected with Salmonella develop diarrhea, fever, and abdominal cramps 12-72 hours after infection. Infection is usually diagnosed by culture of a stool sample. The illness usually lasts 4-7 days. Although most people recover without treatment, severe infections may occur. Infants, elderly persons, and those with impaired immune systems are more likely than others to develop severe illness. When severe infection occurs, Salmonella may spread from the intestines to the bloodstream and then to other body sites, and can cause death. In these severe cases, antibiotic treatment may be necessary.
Advice to consumers
Until health officials know that the contaminated product or products are no longer on the market, persons with increased risk of severe infection, including infants, elderly persons, and those with impaired immune systems, should not eat raw jalapeño peppers or raw serrano peppers. They should also only eat raw tomatoes that are on the FDA safe list. Produce grown at home is not part of this warning. Other persons who are concerned and who want to reduce their risk of Salmonella infection can take similar precautions. Consumers should be aware that raw jalapeño peppers are often used in the fresh preparation of salsa, pico de gallo, and other dishes.
At this time, FDA is advising U.S. consumers to limit their tomato consumption to specific types and specific sources. These include cherry tomatoes; grape tomatoes; tomatoes sold with the vine still attached; tomatoes grown at home; and red plum, red Roma, and round red tomatoes from specific sources listed. Consumers should be aware that raw tomatoes are often used in the preparation of fresh salsa, guacamole, and pico de gallo, are part of fillings for tortillas, and are used in many other dishes.
Consumers everywhere are advised to follow the general food safety guidelines below:
- Refrigerate within 2 hours or discard cut, peeled, or cooked produce items, including tomatoes and peppers.
- Avoid purchasing bruised or damaged tomatoes, peppers, and other produce items, and discard any that appear spoiled.
- Thoroughly wash all tomatoes, peppers, and other produce items under running water.
- Keep produce items that will be consumed raw separate from raw meats, raw seafood, and raw produce items.
- Wash cutting boards, dishes, utensils, and counter tops with hot water and soap when switching between types of food products.
FDA recommends that U.S. retail outlets, restaurants, and food service operators offer only fresh and fresh cut red plum, red Roma, and round red tomatoes and food products made from these tomatoes from specific sources listed. Cherry tomatoes, grape tomatoes, and tomatoes sold with the vine still attached from any source may be offered.
More information about Salmonella and this investigation can be found at:
- Salmonella FAQ
- Timeline for Reporting of Cases
- New Mexico Department of Health [PDF – 191 KB]
- Kansas Identifies 3 Cases Linked to Multi-State Salmonella Outbreak
- Kentucky Cabinet for Health and Family Services Press Release
- Indiana State Department of Health Media Update on Salmonella Outbreak
- New Jersey Department of Health and Human Services: NJ Reports Four Salmonella Cases Linked to Multi-State Outbreak
- Utah Department of Health: Health News
- Information on the safe handling of produce [PDF - 2 pages]