28 September 2000
There is at present no effective vaccine against cholera. The only way to prevent its spread is to interrupt the faecal-oral cycle of contagion. The ways MSF teams do this include:
providing health education to a population on how to prevent diarrhoeal disease. The messages include hand-washing, disposal of faeces and protection of household water stocks. provision of soap to refugees.
working with the community to ensure they have pit latrines. The minimum number required in an emergency situation is 1 latrine per 20 head of population.
setting up adequate supplies of safe water. The minimum quantity required in an emergency population is 10 litres per person per day.
In all of these preventive activities MSF water and sanitation engineers and logisticians have a vital role to play - just as important as the role of doctors and nurses.
During the floods in Bangladesh in 1998, many thousands of water wells across the country became contaminated by the rising waters. Cholera vibrios were washed down the pump shafts into the water table below. The greatest danger came after the flood waters started to recede, when people went home and began using their wells again. Part of the health education given by MSF teams to villagers was instruction on how to disinfect their wells:
An example - Protecting water supplies from cholera
unbolt the cover plate from the pump casing, and remove the pump handle.
pour a few hundred grams of bleach powder down the shaft. The bleach releases chlorine, which is a strong disinfectant, capable of killing cholera vibrios.
re-assemble the pump.
allow the bleach to stay there for 12 hours.
then pump water from the well for an hour, allowing it to drain away. After that your water will be safe to drink.