Vaccinating fewer than half of Haiti’s population of 10 million should brake a cholera epidemic that has claimed nearly 8,000 lives and made more than 635,000 people ill, scientists said on Thursday.
With experts divided on the efficacy of cholera vaccination, Haiti has seen no widespread inoculation effort apart from a pilot project in 2012 that targeted one percent of people in one of the world’s poorest nations.
Using a mathematical model, scientists in the United States determined that vaccination coverage of 46 per cent of the population would “suppress transmission.”
“In the current debate on the use of cholera vaccines… our results suggest that moderate cholera vaccine coverage would be an important element of disease control in Haiti,” the team wrote in the journal Nature Scientific Reports.
Cholera, which causes potentially deadly diarrhoea, is spread by ingesting food or water contaminated with a bacterium carried in human faeces and spread through poor sanitation and dirty drinking water.
The World Health Organisation says there are about 100,000 to 200,000 cholera deaths worldwide every year out of an estimated three to five million infections.
In Haiti, the current outbreak had killed 7,912 people by December 31, according to the study.
The country had been cholera-free for decades until cases were recorded in October 2010 in the aftermath of a devastating earthquake.
It is widely believed to have originated around a camp of Nepalese peacekeepers in the central town of Mirebalais and spread quickly thanks to earthquake-related disruption of water and sewerage facilities.
Haiti’s population had no natural immunity against cholera after such a long absence, further aiding its spread.
A UN probe found there was no way of knowing what caused the epidemic, but disease experts have said the cholera strain in Haiti matched the prevalent strain in Nepal, where cholera is endemic.
Talks between the Haitian health ministry, the WHO and Pan-American Health Organisation on launching a vaccination campaign “are taking place, but nothing has been agreed yet,” the WHO said in response to an email query from AFP.
Unless cholera is contained, it may become endemic to Haiti, said study co-author Zindoga Mukandavire from the University of Florida.
“This is because Haiti has a large estuarine environment which may act as a possible long-term reservoir for cholera,” the infectious diseases expert told AFP.