This may be one of the more notable years for Salmonella food poisoning. First, there was a modest outbreak in the eating clubs at Princeton University and now a larger outbreak in Texas and New Mexico. This is the first time that I can recall in my almost 30 years as a card-carrying food microbiologist that there has been this many highly-publicized cases of Salmonella food poisoning in one year. Although I don’t wish Salmonella gastroenteritis on anybody, it is kind of rewarding that an organism that led to my PhD is making headlines once again. Typically, Salmonella outbreaks are not noteworthy and rarely receive much notice— usually taking a backseat to potentially life-threatening outbreaks of enteropathogenic Escherichia coli.
Like the Princeton outbreak, the exact source of the Salmonella infection is unclear. That said, public health and CDC officials are leaning towards large, raw tomatoes. In 2006, the Food and Drug Administration discovered that consumption of tomatoes in restaurants had caused a salmonella outbreak that affected 21 states. , “until the source of the outbr
eak is identified federal and local health officials in both states have recommended that infants, the elderly and anyone with an impaired immune system avoid eating Roma and red round tomatoes that are not grown at home or sold attached to the vine.” So far, 40 confirmed cases, with patients ranging in age from 3 to 82, have been reported in New Mexico and Texas since April. To date, 17 people have been hospitalized, but no deaths have been reported.
Molecular analyses indicated that all of the cases in New Mexico and Texas were caused by the same strain, a relatively rare serovar called Saint Paul (6th most common serovar infecting humans). Federal health officials at the Centers for Disease Control in Atlanta, GA fear that this may be the beginning of a large national outbreak of Salmonella gastroenteritis. This is because about 30 cases caused by the Saint Paul strain, have also been reported this year in Arizona, Colorado, Idaho, Illinois, Indiana, Kansas and Utah. Like the New Jersey, Texas and New Mexico outbreaks, the cause of those other outbreaks is under investigation.
Salmonella gastroenteritis generally last between four and seven days, and most people are able to recover without medical (antibiotic) treatment. But, it can sometimes lead to death in immunocompromised adults or young children. Symptoms include headache, nausea, abdominal pain, diarrhea and sometimes vomiting. Although textbook descriptions of the pathogenesis of Salmonella gastroenteritis generally portray it as a mild illness, I can tell you that people I know (lab mates of mine) who came down with the disease (gee, how did that happen?) suggest otherwise!
I suspect that fecally-contaminated water may be source of the infection. But, then again, it has been almost 30 years since I thought about Salmonella gastroenteritis. That said, I don’t think that you ever forget the essence or minutiae of your thesis work!
For those of you who are interested, the electron micrograph of Salmonella typhimurium shown with this post is from my PhD dissertation. As I recall, the electron micrograph was taken in 1980 and the bacterium shown in the micrograph was grown for 48 hours on nutrient agar . Althought I would like to take credit for the shot (nice pose eh?), it was taken by Phil Hegge in the Department of Bacteriology at the University of Wisconsin-Madison, my alma mater. if you look closely you may be able to see fimbriae along with the flagella.
Until next time
Good Luck and Good Job Hunting (and remember to wash your tomatoes)!!!!!
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The Centers for Disease Control and Prevention said about 25% of teenage girls received at least one dose of Merck & Co.'s Gardasil vaccine in 2007, providing the first national estimate of usage of the company’s controversial anti- HPV (cervical cancer) vaccine.
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A post at the Pharmalot blog