Foodborne botulism is a severe illness that results from the ingestion of a preformed toxin produced by a bacterium, Clostridium botulinum, in contaminated food. Death can occur in up to 60% of untreated cases; supportive care and prompt administration of antitoxin have reduced mortality in the United States to less than 10%. Outbreaks of botulism have been linked to improperly preserved vegetables, fruits, and meats including fermented fish products, sausages, smoked meat, and seafood.
With foodborne botulism, symptoms begin within 6 hours to 10 days (most commonly between 12 and 36 hours) after eating food that contains the toxin. Symptoms of botulism include double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth, and muscle weakness that moves down the body, usually affecting the shoulders first, then the upper arms, lower arms, thighs, calves, etc. Paralysis of breathing muscles can cause a person to stop breathing and die, unless assistance with breathing (mechanical ventilation) is provided.
Botulism is not spread from one person to another. Foodborne botulism can occur in all age groups. A supply of antitoxin against infant botulism is maintained by the California Department of Public Health’s Infant Botulism Treatment and Prevention Program, and a supply of antitoxin against other kinds of botulism is maintained by the Centers of Disease Control and Prevention (CDC). The antitoxin is most effective in reducing the severity of symptoms if administered early in the course of the disease. Most patients eventually recover after weeks to months of supportive care.
Botulinum toxin has been of concern to the US military and its allies as a biowarfare weapon since World War II and, in more recent times, by the CDC as a potential bioterrorist threat to the public. The most effective means of defending against the toxin is by inducing a protective immune response through vaccination. Vaccination with an appropriate antigen will produce neutralizing antibodies that will bind to and clear the toxin from circulation before it can enter nerve cells and block neurotransmission. Immunity from botulism, however, has the disadvantage of precluding an individual from realizing the potential benefits of therapeutic botulinum toxin, if such a need were to arise. Botulinum toxin has been used in the treatment of numerous neuromuscular, autonomic, and sensory disorders since it was first approved for the management of strabismus and blepharospasm by the Food and Drug Administration (FDA) in 1989. Notwithstanding the value of the neurotoxin as a therapeutic drug, vaccines have been and will continue to be an important line of defense for those who work with the toxin (at-risk workers) and a select population of the military, law
CASE STUDY #3 BOTULISM
enforcement, and first responders. The first vaccine used to protect against botulinum neurotoxin was a chemically detoxified extract from Clostridium botulinum. A Pentavalent botulinum toxoid (PBT) vaccine in service today is administered under an Investigational New Drug (IND) application held by the CDC. Recombinant subunit vaccines are in development and a bivalent H(c) vaccine (rBV A/B (Pichia pastoris)) is presently being evaluated in a phase II clinical trial. This review focuses on botulism and the development of vaccines for its prevention.
On January 01, 2016, a physician at a Florida hospital telephoned the Directorate of Epidemiology of the Florida Health and Hospital Services (FHHS) to report two possible cases of botulism. The patients, both women, presented with drooping eyelids, double vision, difficulty swallowing, and respiratory problems. One patient had onset of symptoms on December 28 and the other on December 29. The physician had drawn blood and collected stool specimens from the women to test for botulinum toxin but no results were available.
Upon questioning, it was learned that both patients were drivers for the same bus company and drove the same route and shift. The patients knew each other but worked on different days of the week. They had not eaten together in more than a month. To find additional cases, the FHHS contacted all employees of the bus company with the ill drivers to see if any had symptoms suggestive of botulism.
Botulinum toxin, also called “miracle poison,” is one of the most poisonous biological substances known. It is a neurotoxin produced by the bacterium, an anaerobic, gram-positive, spore-forming rod commonly found on plants, in soil, water and the intestinal tracts of animals. Currently it is used in almost every subspecialty of medicine. In 2002, the FDA approved the use of Botox® (Botulinum toxin-A) for the cosmetic purpose of temporarily reducing forehead frown lines.
As the chief of biostatistics, you were provided a data set of botulism outbreaks among cities in the state of Florida. During 2010–2016, a total of 27 cities in Florida experienced outbreaks of foodborne botulism.
QUESTIONS -As a public health practitioner in Florida, what are the major concerns raised by these two possible cases of botulism?
-How might you go about swiftly determining if there are other cases of botulism associated with the cases and how would you use your data analysis to advise the community and the Director of FHHS?
-What key points would you include in the press release?
KEY BIOSTATISTICS TASKS
A. Test the hypothesis that vaccination of the population is effective in the prevention of foodborne related outbreaks.
B. Calculate the attack rate for foodborne botulism.
C. Regression Analysis of the relationship between:
-Population size and number of cases
-Average age and Population size
-Vaccination number and population
As a public health practitioner in Florida, what are the major concerns raised by these two possible cases of botulism? -How might you go about swiftly determining if there are other cases of botulism associated with the cases and how would you use your data analysis to advise the community and the Director of FHHS? -What key points would you include in the press release? KEY BIOSTATISTICS TASKS A. Test the hypothesis that vaccination of the population is effective in the prevention of foodborne related outbreaks. B. Calculate the attack rate for foodborne botulism. C. Regression Analysis of the relationship between: -Population size and number of cases -Average age and Population size -Vaccination number and population
