Botulism natural history, complications and prognosis
Complications
Botulism can result in death due to respiratory failure. However, in the past 50 years, the proportion of patients with botulism who die has fallen from about 50% to 8% due to improved supportive care. A patient with severe botulism may require a breathing machine as well as intensive medical and nursing care for several months. Patients who survive an episode of botulism poisoning may have fatigue and shortness of breath for years and long-term therapy may be needed to aid their recovery.
Infant botulism has no long-term side effects, but can be complicated by nosocomial adverse events. The case fatality rate is less than 1% for hospitalized infants with botulism.
Some specific possible complications are:
- Aspiration pneumonia and infection
- Long-lasting weakness
- Nervous system problems for up to 1 year
- Respiratory distress
Prognosis
The prognosis depends upon the particular case. The amount of botulinum toxin an individual is exposed to will play a role in the overall prognosis, but early treatment will significantly decrease the chance of death.
There are in fact 7 different forms of the toxin, and type A generally causes the most severe form of Botulism. An overall mortality rate of approximately 5-10% is suspected for the foodborne form of Botulism. Patients that are much older (older than 60) and young patients have a higher mortality rate than the average 5-10%.
Wound botulism is, on average, more fatal than foodborne botulism. Wound botulism carries a mortality rate of approximately 15%.
The mortality rate of infant botulism is much lower; usually less than 1%.
The recovery period for botulism is fairly long. It ranges from approximately 30 to around 100 days. Sometimes patients need to stay on a ventilator for a long period of time to assist with breathing. There can also be a period of generalized weakness for up to a year after recovery from botulism.
Death from botulism mainly occurs from a few reasons:
- Respiratory failure, possibly due to a delayed diagnosis.
- Complications in the hospital such as a nosocomial infection.
- Usually pneumonia