Half a century ago, the Dominican Republic and Haiti combined forces in a bold but ultimately unsuccessful initiative: to eliminate malaria from the island of Hispaniola. Now, despite continuing political tensions, they are uniting again for a fresh attempt.
“There is longstanding interest in Hispaniola to make it a malaria-free region,” says Patrick Kachur, chief of the US Centers for Disease Control and Prevention, which is working on the programme. “Both countries are interested and, politically, there is the will.”
Yet the experience of recent years — and the limited resources available — highlight the need for a more targeted approach.
Malaria and the mosquitoes that carry it were probably brought to the Caribbean by slaves in the late 15th century. Plantation agriculture helped its spread by creating stagnant pools of water allowing mosquitoes to breed.
Today, the island of Hispaniola is the last place in the region where the disease is endemic, and its continued presence has periodically led to cases spreading to nearby countries such as Jamaica. There are an estimated 15,000-30,000 cases a year in Haiti, and fewer than 50 deaths.
Then, US funding for such programmes diminished in the 1960s, slowing the momentum.
Widespread use of DDT also went out of fashion, reflecting environmental concerns.
While the Dominican Republic had cut annual infections to just 21 by 1968, Haiti — already falling behind its neighbour economically and politically — struggled to keep pace, in turn providing a way for malaria to spread back across the border.
Its International Task Force for Disease Eradication concluded that elimination was technically feasible, medically desirable and economically beneficial. The aim, with estimated total funding requirements of $194m, is to end malaria on Hispaniola by 2020.
Jean Frantz Lemoine, head of Haiti’s malaria control programme, says he believes the elimination objective is worth pursuing, but he remains cautious about whether the scale of additional funding required is achievable.
According to the World Malaria Report 2014, support dropped from a recent peak of $8m in 2004 to almost zero in 2010, rising again since, but still to less than $4m in 2013. The good news is that in Haiti the parasite remains sensitive to chloroquine — a cheap and widely available medicine — as opposed to many other parts of the world where it is ineffective.
Furthermore, the introduction in recent years of rapid diagnostic tests has shown that malaria may in fact be less common in Haiti than was thought. But it has also demonstrated the poor quality of reporting. That highlights the need for more accurate compilation of test results to focus efforts where they are needed, using tools such as text messaging and geospatial mapping.
There are other particularities of malaria in the region.
According to the CDC, in Africa mosquitoes typically bite overnight and indoors, while people are sleeping. In Haiti, by contrast, they tend to bite earlier in the evening, between 5.30pm and 9pm. They also typically do so largely outdoors, or fly outdoors after biting inside, rather than lingering on internal walls or ceilings.
That means insecticide-treated bed nets — despite being widely funded and distributed by donors in the country — are not particularly effective either in protecting people from being bitten or in killing mosquitoes. Indoor residual spraying with insecticide may also prove less effective than elsewhere.
Instead, specialists are examining how to provide “mass drug administration”, the idea being pre-emptively to provide drugs to populations at high risk of infection, in an effort to eliminate the parasite and stop it circulating.