Cholera has been investigated in the past as a biological weapon.
It does not spread easily from human to human nor is it likely
to be used as an aerosol. Therefore, major drinking water supplies
would have to be heavily contaminated for this agent to be effective
in biowarfare.
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Symptoms
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Cholera is a severe gastrointestinal disease. Incubation ranges
from 12-72 hours depending on the dose of ingested organisms.
Onset of illness usually is sudden. Initially, the disease presents
with intestinal cramping and painless diarrhea. Vomiting, malaise,
and headache often accompany the diarrhea, especially early in
the illness. Diarrhea is profuse - as much as 7 liters/day. That's
almost 2 gallons. Due to this quantity severe dehydration with
shock can develop.
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How does it spread?
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Humans acquire the disease by consuming water or food contaminated
with the organism.
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Diagnosis
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Under a microscope, the stool has few or no red cells, white cells,
and almost no protein are found. The organism can be identified
in liquid stool or enrichment broths by darkfield or phase contrast
microscopy and by identifying darting motile Vibrio species. Bacteriologic
diagnosis is not necessary for treatment, as it can be diagnosed
clinically.
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Treatment
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Treatment is primarily replacing fluids and electrolytes. The
best is the World Health Organization 's oral dehydration therapy
- a solution (3.5 g NaCL, 2.5 g NaHC03, 1.5 g KC1 and 20 g glucose
per liter). Intravenous fluid replacement is occasionally needed
when vomiting is severe, when diarrhea output exceeds 7 liters/day,
or when severe dehydration with shock has developed. Antibiotics
shorten the duration of diarrhea and reduces fluid loss.
Specifics on treatment can be found here
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Vaccine
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Vaccine is not recommended for routine protection in areas where
cholera is prolific since its only 50% effective and protection
lasts no more than 6 months. When vaccine is called for, the initial
dose is two injections given at least 2-4 weeks apart with booster
doses every 6 months.
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Mortality
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Without treatment, death may result from severe dehydration, hypovole
mia and shock.
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Sources:
CDC; http://www.bt.cdc.gov/
Federation of American Scientists; http://www.fas.org/nuke/intro/bw/agent.htm
CBS Bioterrorism Interactive; http://cbsnews.cbs.com/
USAMRIID's Medical Management of Biological Casualties Handbood;
Fourth Edition February 2001; pages 9-10; http://usamriid.detrick.army.mil/education/bluebook/bluebook.pdf
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