Cholera: Disease of disaster

In the days after Cyclone Nargis sent a wall of seawater through Burma's low-lying Irrawaddy Delta in May 2008, the threat of disease became a major concern for survivors.

The United Nations estimated that at least 1.5 million people were "severely affected," needing food, shelter and clean drinking water.

Clean drinking water is especially critical in the wake of a disaster of this magnitude. Without it, people begin to dehydrate within a few days. And with seawater and large numbers of decomposing bodies overwhelming water supplies, disease quickly becomes a threat.

Among the most common diseases to hit areas where drinking water is compromised is cholera.

Although cholera did not turn out to be a major problem in Burma after the storm, it did later in the year in Zimbabwe. An ongoing political crisis led to a deterioration in government services including water treatment and sanitation. By mid-December,more than 16,000 cases were reported across the country.The outbreakclaimed at least775 lives.

In October 2010, in Haiti almost 10 months after a devastating earthquake killed more than 200,000 people and extensively damaged an already precarious infrastructure hundreds of cholera cases were confirmed in rural areas north of the capital, Port-au-Prince. The outbreak spread. A month later, more than a thousand people had died and 18,000 required hospital care.

What is cholera?

Cholera is an intestinal infection caused by the bacterium Vibrio cholerae. You get it from drinking

contaminated water or eating contaminated food. About five per cent of infected people will become severely ill and will develop profuse watery diarrhea, vomiting, and leg cramps.

In severely ill people, cholera will cause rapid dehydration and shock. If you have a severe case and you are not treated, you could die within a few hours.

However, most people who are infected don't get sick, although the bacterium can be present in their feces for up to two weeks.

Of those who do get sick, 80-90 per cent of cases are either mild or moderate and often indistinguishable from other types of acute diarrhea.

How prevalent is cholera?

According to the World Health Organization, there were at least 236,896 cases of cholera in 52 countries in 2006. After years of declines, the number of cases rose dramatically in 2006 to levels not seen since the 1990s.

All but 2,000 of those cases were reported in Africa.

The number of deaths in 2006 was 6,306 three times the number recorded a year earlier.

How is cholera treated?

Rehydrating the patient is the most effective way of treating someone with severe cholera. There are at least two ways of doing this:

• By drinking large quantities of a rehydration solution a prepackaged mixture of sugar and salts that can be mixed with clean water.
• By intravenously replacing lost fluids, in severe cases.

Antibiotics may also be used in an effort to shorten the course and the severity of the illness. But antibiotics are not as critical in the treatment as rehydration.

Is cholera just a risk in areas hit by disaster?

Cholera is a risk anywhere that hygiene and access to clean drinking water is a problem. It was not uncommon in North America in the 1800s, but it has been rare in industrialized countries for the past 100 years or so.

Cholera remains a threat in many developing countries. There have been a few cases in Canada over the past several years, but they have all involved travellers returning from countries where cholera was present.

How do I protect myself?

The best way to ensure that you do not get infected is to practise good personal hygiene and make sure you drink clean water. If you have doubts about the drinking water, stick to bottled water or water that you have boiled or treated with chlorine or iodine. Eat only foods that have been thoroughly cooked and are still hot.

There are two oral vaccines available. Dukoral offers some protection against traveller's diarrhea for up to three months. Mutachol is partially effective against one strain of cholera.

The U.S. Centers for Disease Control does not recommend oral cholera vaccines, nor does the World Health Organization under normal circumstances. Reasons cited include:

• The risk of contracting the disease for travellers is low.
• The vaccines are expensive.
• The vaccines offer limited protection.

However, the WHO does recommend pre-emptive use of oral cholera vaccines in emergency situations. The trick is getting enough of the vaccine to stricken areas.