Blood donors who live with or have handled reptiles may be inadvertently donating something dangerous: Salmonella bacteria. A recent article in The New England Journal of Medicine reports that platelets donated by an Oklahoma man who owns a boa constrictor were given last year to two female patients who later developed sepsis as a result of exposure to Salmonella bacteria. One of the patients died.

The article's author, Dr. Ron Gilcher, president and medical director of the Oklahoma Blood Institute, wrote that once Salmonella was detected in the two women, the donor was asked to submit to tests. During conversations, the man mentioned his pet snake, which tipped off scientists.

Said Gilcher, "Knowing that reptiles, and specifically snakes and turtles, are known to carry Salmonella, we asked him if we could culture his pet snake." A fecal sample, showed that the boa carried the same strain of Salmonella bacteria that was found in the sepsis-infected patients. The owner had demonstrated no symptoms of salmonellosis when he donated the platelets, although he reportedly had been sick with fever, cramps and diarrhea about two-and-a-half weeks before donating.

The growing popularity of reptiles as pets—nine million could be found in homes in 2000, a million more than in 1998—means that Salmonella-contaminated platelet donations are likely to increase. Because reptiles do not become ill by Salmonella bacteria, and owners may be infected by salmonellosis and show no symptoms, there is a strong chance that other reptile owners will donate platelets without realizing they carry the Salmonella bacteria. Compounding the problem is the fact that platelets must be stored at room temperature, which allows the bacteria to grow.

According to Gilcher, The Oklahoma Blood Institute will start testing the bacterial cultures of donated platelets in December 2002, but no other blood center is known to perform such tests. The New England Journal of Medicine article claims that "reptiles may account for as many as 3 to 18 percent of the estimated 1.4 million cases of salmonella infections that occur annually in the United States."

Even when it does not trigger sepsis, salmonellosis is a serious illness. It causes diarrhea, vomiting, fever, and chills, and may develop into invasive illnesses such as meningitis. In several cases, salmonellosis in children has resulted in severe illness or death. In 1999, responding to an upsurge in cases of reptile-associated salmonellosis, the Centers for Disease Control and Prevention (CDC) issued a public advisory warning that 93,000 people each year contract salmonellosis from contact with reptiles and amphibians. The CDC recommends that children, pregnant women, and persons with compromised immune systems avoid all contact with reptiles and amphibians.

Now those who plan to donate blood may be candidates for that list as well.