Hammocks could be added to malaria control arsenal
[HANOI] Insecticide-treated hammocks could cut malaria rates in remaining pockets of high transmission in the forests of South-East Asia, researchers say.
Hammocks made from nylon, ropes and an insecticide-treated bednet were given to 7,000 people in Ninh Thuan province in central Vietnam. Researchers then noted new malaria cases in both the study group and a hammock-free control group.
Both groups showed a decrease in new incidents of malaria, however the reduction was twice as large in the study group, suggesting hammocks make a useful additional control method. The study's results were published in PLoS ONE this month (7 October).
New cases of malaria in Vietnam dropped by more than 90 per cent between 1991 and 2007 but the disease persists in remote forested areas in the central highlands and along the country's borders. Vietnamese forest workers often use hammocks, and spending time — particularly sleeping — in the forest is known to be a risk factor for malaria.
In the forested areas of South-East Asia, bednets alone cannot control malaria, as the local vector — Anopheles dirus — feeds and rests outdoors, and bites early in the evening. By contrast, the African Anopheles mosquito feeds and rests indoors, and bites at night, making bednets far more effective at reducing transmission.
Hammocks are probably effective in central Vietnam because forest workers often use hammocks to rest after their day's work, says Umberto D'Alessandro, study co-author and head of parasite epidemiology and control at Belgium's Institute of Tropical Medicine.
"Often these people work early then rest, eat and go to sleep," he said. "This is the time when insecticide-treated hammocks may give additional protection."
The researchers say hammocks are cost effective and, judging by their use during the study, could be rapidly accepted by remote communities.
But Trieu Nguyen Trung, head of Vietnam's Quy Nhon Institute of Malariology, Parasitology and Entomology, says that people rarely use bednets or hammocks and awareness must be raised of their importance.
Nguyen Manh Hung, director of the National Institute of Malariology, Parasitology and Entomology and director of the Vietnam Global Fund Malaria Control Project says the Global Fund to Fight AIDS, Tuberculosis and Malaria has awarded Vietnam nearly US$30 million for malaria control until 2013.
Some of this money will be used to distribute hammocks and bednets free of charge, he says.
Link to full article in PLoS ONE