Washing is essential in areas of contaminated water

Cholera has again become a prominent issue in global health affairs because it has flared up in the city of Basra in southern Iraq, in no small part because of the damage to the infrastructure during the recent conflict there.

But the risks of contracting lethal bacterial diseases such as cholera and diarrhoea from polluted water would be massively reduced if people were simply encouraged to wash their hands more.

"It's all a question of education," the WHO's Dr Clareleesh Shenya told BBC World Service's Health Matters programme.

"A person's hygiene is absolutely essential to preventing them getting infected by cholera - that is the mainstay of cholera prevention.

"It's exactly the same preventative measures for typhoid and dysentery."

Infection

Dr Shenya stressed that the risk was particularly high whenever people came into contact with faecal matter.

"People get very much infected when they don't wash their hands properly before preparing food after having cleaned nappies, having passed stool, and so on," she said.

Boil it, cook it, peel it, or forget it WHO advice on avoiding contracting cholera from food

"We have to reinforce the health education message with regard to access to safe water."

Washing in contaminated water has been found to be the most common and effective method of transmission of the disease.

The most recent cases in Basra, where raw sewage is openly flowing in the streets after the destruction of sewage treatment plants, are thought to be due to people drinking the water.

The WHO is very concerned about the Iraq situation

Two hospitals in the city have already reported cases - and the WHO fears there are many more who have not come forward.

"In this situation in Iraq, where we have had a disruption of the public health infrastructure, a disruption of the water system and sanitation, you have the main ingredients for this cholera outbreak," Dr Shenya said.

Africa's "hot zones"

But the problem remains at its worst in Africa.

Three entire regions of the continent - Western Africa, Southern Africa and the Great Lakes region - are described as "hot zones" for cholera by the WHO.

"Mainly it's affecting the poorest of the poor," Dr Shenya stated.

Cholera is also spread due to people eating food that has come into contact with contaminated water.

"We have to give very good health education messages with regard to food safety - that means that food preparation, and also hygiene," Dr Shenya said.

The outbreak of the disease that killed nearly 3,000 in Peru in 1990 was down to the consumption of raw fish, which contained cholera-carrying plankton.

"People were really expecting to die like flies," Dr Claudio Lanata, from the Institute of Nutritional Research in Lima, told Health Matters.

Treatment of cholera is relatively simple, requiring intense rehydration - but, crucially, only with clean water.

Cholera is still at its worst in Africa

In some cases death can occur within hours if the strain is virulent enough, although the WHO estimates this only happens in 5-10% of cases.

Dr Shenya added that it would technically be possible to entirely eradicate these diseases were basic essentials actually available around the globe.

"If the whole world can have access to safe water and sanitation, we will get rid of bacterial and viral diseases that are transmitted through water," she said.