Salmonella In Tomatoes Outbreak Totals 756 Infections

Featured Article
Main Category: Infectious Diseases / Bacteria / Viruses
Also Included In: Nutrition / Diet;  Public Health
Article Date: 27 Jun 2008 - 11:00 PDT

email to a friend   printer friendly   view / write opinions

The US Centers for Disease Control and Prevention (CDC), has increased to 756, up by 200 in the last week, the official count of persons infected with the same rare type of Samonella (serotype Saintpaul) which is believed to come from contaminated raw red tomatoes although the authorities still haven't tracked down the exact source of the contamination.

The new figure is valid from 9 pm EDT, June 25, 2008, said the CDC in a statement on its website. The outbreak affects 34 states and the District of Columbia. No new states have been added to the list from a week ago. The highest numbers of infection have been confirmed in Texas (330), New Mexico (80), Illinois (66), Arizona (38), Maryland (25), and Virginia (22).

By comparing foods eaten by people who are sick with those who are not, epidemiologists have narrowed down the cause of the outbreak to a particular group of raw red tomatoes, these are: red plum, red Roma, and round red tomatoes. Any combination of these and products containing these tomatoes are also likely sources.

The outbreak started in April this year, and since then the 756 people have been officially confirmed as having the same strain of Salmonella Saintpaul with the same genetic fingerprint.

The CDC said it is likely the new cases are not new infections but a backlog of late reports on infections detected before last week. When a person is tested positive for salmonella, the laboratory in that state then sends the results to the state health laboratory for characterization of the particular strain, and they in turn inform the CDC, so there is a lead time delay between local and national recording of the confirmed diagnosis.

Another factor, is that the more awareness that is created about a particular outbreak, the more vigilant the surveillance at local and state levels becomes.

Of the 756, the CDC is able to determine from information accompanying the reports, that 517 of them fell ill between April 10th and June 13th. The patients range from below 1 to 99 years of age, and half are female.

At least 95 of the infected persons have been admitted to hospital, but no deaths have been officially linked to the outbreak. However, a man in his 60s who died in Texas from cancer was infected with the outbreak strain of Salmonella Saintpaul when he died, and the infection may have contributed to it, said the CDC statement.

This strain of Salmonella Saintpaul was around last year, in 2007, but according to the CDC, only 3 people were confirmed to be infected with it in the whole of the US.

Health officials say it is likely that many more people are infected and going unreported because to confirm the diagnosis a stool specimen is required and many people don't have the test. So it could be that some states not on the official list also have people infected with this strain.

The authorities suggest it is likely that the infection is being spread by tomatoes from a contaminated source that distributes throughout the US.

Over the past week, investigators from the US Food and Drug Administration (FDA) have been inspecting farms in Florida and Mexico that grow tomatoes, and also the various stops the products make on their way to the consumer, but the source of the contamination remains a mystery.

Most people who become infected with Salmonella make a complete recovery without needing treatment. The symptoms include diarrhea, fever, and abdominal cramps, which develop between 12 and 72 hours after infection and the illness lasts from 4 to 7 days.

In some cases however, severe infection can develop, and small children, babies, the elderly and people with weakened immune systems are most at risk. When severe infection occurs, the bacteria can spread from the intestines to the bloodstream, then to the rest of the body, and the result can be fatal. The infection can be treated with antibiotics.

The FDA advises consumers not to eat tomatoes that could be linked to this outbreak, that is red plum, red Roma, and round red tomatoes, unless they know for sure they have come from a safe source (see the FDA list of safe sources at http://www.fda.gov/oc/opacom/hottopics/tomatoes.html). Remember also that dishes like fresh salsa, guacamole, pico de gallo, and tortillas containing tomatoes, and many other dishes, could also contain infected tomatoes.

Tomatoes that should be safe to eat include: cherry tomatoes, grape tomatoes, tomatoes sold with the vine still attached and tomatoes grown at home.

Click here for CDC Question and Answer page on this outbreak.

Sources: CDC, FDA.

Written by: Catharine Paddock, PhD
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today