Symptoms of foodborne botulism may help predict fatality

The extreme toxicity of botulism makes it a potentially lethal type of food poisoning – and a possible agent of bioterrorist attack

The extreme toxicity of botulism makes it a potentially lethal type of food poisoning – and a possible agent of bioterrorist attack. Data from the Republic of Georgia (a former Soviet nation south of Russia) suggest that an infected person’s symptoms could help doctors predict how immediate the risk of death is, allowing physicians to prioritize victim care based on severity of symptoms, according to an article in the August 1 issue of Clinical Infectious Diseases, now available online.

Botulism is caused by eating food contaminated with a naturally occurring bacterium, Clostridium botulinum. C. botulinum produces a potent neurotoxin that can have drastic effects on the body. Symptoms include double vision, dry mouth, difficulty swallowing, dilated pupils, drooping eyelids and slurred speech, followed by eventual paralysis.

Researchers from the U.S. Centers for Disease Control and Prevention (CDC) and the Republic of Georgia’s National Center for Disease Control (NCDC) studied 706 cases of botulism in Georgia, which has the highest reported rate of foodborne botulism of any country. They discovered that the patients at highest risk of dying were those who reported to the hospital with shortness of breath and impaired gag reflex but lack of diarrhea. This constellation of symptoms, if validated in the United States and other countries as predictors of death, would allow doctors to give first consideration to patients who are at highest risk of dying in a botulism outbreak.

Botulism is exceedingly rare in the United States, so both patients and doctors need to be alert to the symptoms, according to lead author Dr. Jay Varma of the CDC. “Patients who have symptoms of botulism need to seek medical attention immediately,” said Dr. Varma. However, since weakness and difficulty speaking or swallowing can also indicate a stroke, he said, “doctors need to recognize when patients have botulism, not a stroke, and then institute treatment quickly.”

Co-author Dr. Jeremy Sobel of the CDC emphasized that the study’s findings were specific to the type of botulism found in the Republic of Georgia’s soil, and reiterated that accurate diagnosis and rapid treatment were essential in any case of botulism infection. “The important thing is that physicians quickly identify the illness based on the clinical syndrome,” said Dr. Sobel, “and that upon suspicion of botulism the physicians contact the public health system immediately so that the source of the toxin can be identified and the population warned and protected.” Patients should receive antitoxin and be placed in intensive care as soon as possible, he added.
In an accompanying editorial commentary, other CDC researchers suggest additional preparations necessary for responding to a botulism outbreak: sufficient supplies of antitoxin and other medical supplies should be available and “a coordinated medical system and response plan” should be in place.