Photo: WHO/TDR Mark Edwards
Deforestation can encourage malaria outbreaks.
New roads promote deforestation that not only reduces the world's carbon balance but also boosts malaria rates, according to Dr. Margaret Kosek, an infectious-disease expert at Johns Hopkins Bloomberg School of Public Health.
Dr. Kosek and her team study the impact of deforestation on the spread of infectious diseases in the Peruvian Amazon. When roads are built, culverts are formed alongside that create pools of water. These are ideal places for mosquitoes to lay their eggs, according to the researchers. Roads also bring outsiders to villages that have been largely isolated. If these newcomers carry malaria, mosquitoes could bite them, pick up the parasites and infect new victims, the scientists say.
In the Peruvian Amazon, 75 percent of the forest disruption, from 1999-2005, was within 12 miles of a road. Consequently, the areas that had suffered the most deforestation also suffered more malaria.
Dr. Kosek and her team recently surveyed an area where the Peruvian government plans to put in a highway. The road will go from the frontier river village of Mazan, through the Amazon jungle, to the city of Iquitos. The team wants to see what impact this will have. If they can unravel the health effects of building roads through the jungle, they say, it could help them find ways to prevent some of the problems.
However, many people who live in the area see the road as a sign of progress. It will provide construction jobs and help farmers get their goods to market. But the research team knows the road will also increase the number of mosquitoes, including those that carry malaria.
Dr. Kosek is Principal Investigator on a Fogarty International Research Scientist Development Award.