by Paul Auerbach, M.D.
reposted with permission from the Medicine for the Outdoors Blog
Let's
just say that people who like to be outdoors are often the same people
who like to eat tomatoes. Tomatoes are a staple food at cookouts, on
backpacking trips when fresh food is carried, for lunch and dinner on
the river, etc. Nothing tastes better than a homegrown beef tomato
sprinkled lightly with a bit of salt and pepper, and perhaps a touch of
balsamic vinegar.
Over the past few weeks, we were informed
that now we all needed to be extra careful, because we were supposedly
in the midst of a multi-state (U.S.) outbreak of infections caused by Salmonella serotype Saintpaul, attributed to consumption of raw tomatoes, and in particular, red plum, red Roma, or round red tomatoes.
Thirty-two
states and the District of Columbia were said to have reported
infections to the Centers for Disease Control, via the identification
of Salmonella strains from
ill persons routed for identification through the State health
departments. The reports were presumedly linked to tomatoes - consumed
at home or in restaurants. There was no definitive link to tomatoes
consumed "in the wild" - and none to my knowledge on an expedition. Now
it appears that these Salmonella infections
may not have originated with tomatoes after all, but from some unknown
carrier(s) of the bacteria. We are not yet even sure if the
contaminated food was produce, but that is a possibility. If it was not
tomatoes, perhaps it was something served with tomatoes, or a food
product made with tomatoes, such as salsa. If it was salsa, then it
could have been any of the other ingredients, such as green onions,
cilantro, or jalapeño peppers.
If there are contaminated
tomatoes, or any other vegetable, meat, or other food product(s) in
circulation, sooner or later, someone will get become sick after eating
the product during a picnic or an outdoor trip. In retrospect, and for
the purpose of avoiding future illness, it is very important to note
that we do not have information about how the culprit tomatoes were
supposedly handled prior to consumption - were they washed, and if so,
in what manner? I don't imagine that we will ever learn these details,
particularly if the very origins of the reported illnesses are in doubt.
So, that leads us back to a general discussion of infection with Salmonella, which is a very real cause of diarrheal illness. There are multiple species of Salmonella, including Salmonella typhi,
which causes typhoid fever. The bacteria normally reside in the
intestinal tracts of humans and other animals, including birds. The
most well known causes of Salmonella food poisoning are contaminated beef, poultry, milk, and eggs. Salmonella food poisoning (infection), usually caused by S. typhimurium or S. enteritidis,
typically causes diarrhea (loose and watery stools, usually without
blood), fever, and abdominal cramping 12 to 72 hours after incubation
of the infection. Untreated with an antibiotic, the illness usually
lasts from 4 to 7 days. The infection may spread and cause the victim
to become seriously ill, or rarely, to die. On occasion, persons with Salmonella infection develop a post-infection syndrome of painful joints, irritated eyes, and pain on urination.
For
gastroenteritis, antibiotic therapy is usually not indicated, because
it does not shorten the duration of the disease. Furthermore,
antimotility drugs, such as loperamide (Imodium), are not recommended,
because they may prolong contact time of the bacteria in the bowel, and
prolong or worsen the illness. However, antibiotics are often
recommended for Salmonella gastroenteritis
in infants younger than 3 months, infants younger than 12 months with
temperatures higher than 102.2°F (39°C), and persons with certain blood
disorders, HIV infection or other cause of immunosuppression (e.g.,
diabetes or chronic steroid therapy), cancer, or chronic
gastrointestinal illness. The recommended antibiotics for such
individuals include ampicillin, amoxicillin,
trimethoprim-sulfamethoxazole, cefotaxime, ciprofloxacin, and
ceftriaxone, among others.
So far, in this current Salmonella outbreak,
there have been no directly-attributable deaths reported, but at least
53 persons have been hospitalized. Overall, the number of afflicted
persons is likely greater than that reported, because many people who
develop diarrhea don't seek medical care and/or obtain a stool culture.
The
Food and Drug Administration (FDA) has been advising consumers in the
U.S. to be cautious, and to choose for consumption cherry tomatoes,
grape tomatoes, tomatoes sold with the vine attached, homegrown
tomatoes (more reason to "go organic"), and to avoid red plum, red
Roma, and round red tomatoes unless they come from reliable sources.
Of course, much as one needs to avoid contaminated ice in beverages,
one should be aware that if tomatoes are the culprits, then raw
tomatoes used to prepare sauces, salsa, cold soups, and other food
products can carry Salmonella. Ditto for lettuce or any raw fruit or vegetable. The truth is that right now, we don't know precisely what to avoid.
Here are additional precautionary measures that place emphasis on food handling and preparation:
1. Within 2 hours of use, refrigerate or discard cut, peeled, or cooked fruits and vegeatables.
2. Do not purchase bruised or damaged fruits or vegetables.
3.
Wash all vegetables and fruits thoroughly under running water. If you
are camping, use properly disinfected water. Soaking vegetables and
fruits with a skin or "peel" in an iodinated disinfecting solution,
then rinsing with disinfected water to remove the residual iodine (and
improve the taste) is a common practice in some third world restaurants.
4. Keep raw produce for consumption separate from raw meats and seafood.
5.
Wash all cutting boards and surfaces, dishes, utensils, and counter
tops with soap and hot water in between handling different types of
food products.
6. One might consider peeling tomatoes, but there is
not yet evidence that this makes a difference in diminishing the number
of infections, which may not be caused by the tomatoes anyway.
The U.S. Department of Agriculture has an excellent Fact Sheet entitled "Salmonella Questions and Answers."
In summary, the recent reports of Salmonella infection,
while perhaps attributable to tomatoes, may well have been created by
an alternative source(s). The rules for safe food handling and
avoidance of food-borne infection apply to all foods, not just tomatoes.
image of "Tennessee tomatoes go camping" courtesy of blackstarjewelry's photostream
Posted
07-07-2008 11:15 PM
by
Outdoor Ed