Public healthCholera to linger in Haiti for years to come
Worldwide, poor sanitation that spreads cholera and other gut infections accounts for 2.4 million deaths a year, and 6.6 per cent of all life-years lost to disease and disability; the current cholera crisis in Haiti offers a grim example: cholera deaths are climbing sharply in Haiti, after the infection reached the capital, Port-au-Prince, as feared; epidemiologists who have studied other outbreaks predict that hundreds of thousands of Haitians will be stricken by the infection over the next few years as cholera takes hold in the country
Checking the spread of cholera starts with clean water // Source: wn.com
Cholera deaths are climbing sharply in Haiti, after the infection reached the capital, Port-au-Prince, as feared. Epidemiologists who have studied other outbreaks predict that hundreds of thousands of Haitians will be stricken by the infection over the next few years as cholera takes hold in the country.
Nearby countries are also at risk, with with unconfirmed reports of cases in the neighboring Dominican Republic. UN peacekeepers may have been the inadvertent source of the bacteria. New Scientist’s Debora MacKenzie writes that the Haitian outbreak began in the third week of October. The number of known deaths climbed to 544 by 7 November, but has since started to climb sharply with the official number of deaths now nearly 1,000 (see an interactive map here).
“We expect these numbers to continue to rise,” Jon Andrus, deputy head of the Pan American Health Organization (PAHO), the World Health Organization’s regional office for the Americas, said last week. As the disease penetrates remote areas, the real toll could be much higher than the official count.
The bacteria spread when infected feces contaminate water supplies, especially when flooding disrupts sanitation systems. The outbreak started along the Artibonite river while it was flooding. Conditions were worsened by further flooding after hurricane Tomas struck Haiti on 5 November, and cholera persists as long as people keep re-infecting water. “One might expect upwards of 270,000 cases if Haiti’s epidemic continues for several years,” said Andrus.
Just such a scenario unfolded when cholera struck Peru in 1991. That outbreak was largely controlled by 1995, but by then Peru had exported cholera to 16 other countries in the Americas. The infection took hold where there was poor sanitation.
MacKenzie notes that like Peru, Haiti was cholera-free since at least the 1950s, when records began. Because of this, people in the country have no immunity. An oral vaccine is available, but even where cholera is endemic, it is not widely used by the poor, as it works for mo more than two years and so must be repeated.
Treatment with cheap oral rehydration can save most lives if given fast enough, but the disease progresses rapidly, and Haiti’s medical facilities are overwhelmed.
Genetic tests in the United States show the bacteria had a single origin and most closely match strains prevalent in south Asia. They could have arrived in produce or a ship’s ballast water, as they did in Peru, says Luis Gerardo Castellanos, an epidemiologist at PAHO.
Cholera, though, is most frequently spread by infected people who never develop symptoms. Haitians have blamed a military camp in Mirebalais, sixty kilometers north-east of Port-au-Prince, housing Nepalese UN peacekeeping troops. Cholera is endemic in Nepal.
Geography and timing seem to support them. The first cholera cases were reported in Mirebalais and further down the Artibonite river in Drouin and Dessalines, and nearby St Marc.
Sewage pipes are reported to lead from the camp to a nearby stream which flows directly into the Artibonite.
Vincenzo Pugliese, spokesman for the UN mission in Haiti, told New Scientist that the government laboratory sampled water from the stream beside the Nepalese base on 22 October, the day after news of the cholera broke. It found no bacteria. An outbreak of cholera in the Nepalese capital, Kathmandu, however, was reported on 24 September. The current contingent in Haiti, says Pugliese, arrived between 8 and 15 October.
However the cholera arrived, Haiti’s poor sanitation did the rest. Worldwide, poor sanitation that spreads cholera and other gut infections accounts for 2.4 million deaths a year, and 6.6 per cent of all life-years lost to disease and disability, calculates Sandy Cairncross of the London School of Hygiene and Tropical Medicine. The unfolding disaster in Haiti, he says, shows why governments should invest more in sanitation.
