CHOLERA

Cholera is an acute intestinal infection caused by ingestion of food or water contaminated with the bacterium Vibrio cholerae. It has a short incubation period, from less than one day to five days, and produces an enterotoxin that causes a copious, painless, watery diarrhoea that can quickly lead to severe dehydration and death if treatment is not promptly given. Vomiting also occurs in most patients.

SIGNS AND SYMPTOMS

The primary symptoms of cholera are profuse diarrhea and vomiting of clear fluid.These symptoms usually start suddenly, half a day to five days after ingestion of the bacteria.The diarrhea is frequently described as rice water in nature and may have a fishy odor.An untreated person with cholera may produce 10 to 20 litres 3 to 5 US gal of diarrhea a day.Severe cholera, without treatment, kills about half of affected individuals.If the severe diarrhea is not treated, it can result in life-threatening dehydration and electrolyte imbalances.Estimates of the ratio of asymptomatic to symptomatic infections have ranged from 3 to 100.Cholera has been nicknamed the "blue death" because a person's skin may turn bluish-gray from extreme loss of fluids.

CAUSE

Cholera is typically transmitted to humans by either contaminated food or water. Most cholera cases in developed countries are a result of transmission by food, while in the developing world it is more often water.Food transmission occurs when people harvest seafood such as oysters in waters infected with sewage, as Vibrio cholerae accumulates in zooplankton and the oysters eat the zooplankton.

PREVENTION

Sterilization: Proper disposal and treatment of infected fecal waste water produced by cholera victims and all contaminated materials clothin, bedding are essential. All materials that come in contact with cholera patients should be sanitized by washing in hot water, using chlorine bleach if possible. Hands that touch cholera patients or their clothing, bedding, etc., should be thoroughly cleaned and disinfected with chlorinated water or other effective antimicrobial agents.

Sewage: antibacterial treatment of general sewage by chlorine, ozone, ultraviolet light or other effective treatment before it enters the waterways or underground water supplies helps prevent undiagnosed patients from inadvertently spreading the disease.

Sources: Warnings about possible cholera contamination should be posted around contaminated water sources with directions on how to decontaminate the water (boiling, chlorination etc.) for possible use.

Water purification: All water used for drinking, washing, or cooking should be sterilized by either boiling, chlorination, ozone water treatment, ultraviolet light sterilization e.g. by solar water disinfection,or antimicrobial filtration in any area where cholera may be present. Chlorination and boiling are often the least expensive and most effective means of halting transmission. Cloth filters or sari filtration, though very basic, have significantly reduced the occurrence of cholera when used in poor villages in Bangladesh that rely on untreated surface water. Better antimicrobial filters, like those present in advanced individual water treatment hiking kits, are most effective. Public health education and adherence to appropriate sanitation practices are of primary importance to help prevent and control transmission of cholera and other diseases.