Botulism

Botulism

Dr. maitham F jalal M.B.CH.B F.I.C.M.S

Center for Food Security and Public Health Iowa State University 2004

Organism
Clostridium botulinum Gram positive Obligate anaerobic bacillus Spores Resistant to heat, light, drying and radiation Specific conditions for germination Anaerobic conditions Warmth (10-50oC)

Neurotoxins

Seven different types: A through G Different types affect different species All cause flaccid paralysis Binds neuromuscular junctions Toxin: Destroyed by boiling Spores: Higher temperatures to be inactivated

Transmission

Ingestion Organism Spores Neurotoxin Wound contamination Inhalation Person-to-person not documented

Epidemiology

In U.S., average 110 cases each year Approximately 25% food-borne Approximately 72% infant form Remainder wound form Case-fatality rate 5-10% Infective dose- few ograms

Human Disease

Three forms Foodborne Wound Infant All forms fatal and a medical emergency Incubation period: 12-36 hours

Foodborne Botulism

Preformed toxin ingested from contaminated food Most common from home-canned foods Asparagus, green beans, beets, corn, baked potatoes, garlic, chile peppers, tomatoes; type A Improperly fermented fish (Alaska); type E

Center for Food Security and Public Health Iowa State University 2004

Infant Botulism
Most common form Spore ingestion Germinate then toxin released and colonize large intestine Infants < 1 year old 94% < 6 months old Spores from varied sources Honey, food, dust, corn syrup

Wound Botulism

Organism enters wound Develops under anaerobic conditions From ground-in dirt or gravel It does not penetrate intact skin Associated with addicts of black-tar heroin

Adult Clinical Signs

Nausea, vomiting, diarrhea Double vision Difficulty speaking or swallowing Descending weakness or paralysis Shoulders to arms to thighs to calves Symmetrical flaccid paralysis Respiratory muscle paralysis

Infant Clinical Signs

Constipation Lethargy Poor feeding Weak cry Bulbar palsies Failure to thrive

* Selected Mimics that May Lead to Misdiagnosis of Botulism

Diagnosis
Clinical signs Toxin in serum, stool, gastric aspirate, suspected food Culture of stool or gastric aspirate Takes 5-7 days Electromyography also diagnostic Mouse neutralization test Results in 48 hours

Center for Food Security and Public Health Iowa State University 2004

Treatment
Intensive care immediately Ventilator for respiratory failure Botulinum antitoxin Botulism immune globulin Infant cases of types A and G

* Treatment

If diagnosed early, foodborne and wound botulism can be treated with an antitoxin which blocks the actions of toxin circulating in the blood. This prevents patients from worsening in condition. If respiratory failure and paralysis occur, the patient may be put on a breathing machine for weeks plus intensive medical and nursing care. Paralysis will improve after several weeks. Antitoxin is currently not routinely given for treatment of infant botulism.

Human: Prevention

Do not feed honey to children <1 yr of age Proper food preservation methods Proper time, temperature and pressure 80oC for 30 min or 100oC for 10 min Prompt refrigeration of foods Boil foods for > 10 minutes Decontamination Boil suspected food before discarding Boil or chlorine disinfect utensils used