Deforestation Linked to Rise in Malaria Cases

A new study of 67 less-developed, malaria-endemic nations, published in AIMS Environmental Science, led by Lehigh University sociologist Kelly Austin, has found a link between deforestation and increasing malaria rates across developing nations.

Malaria represents an infectious disease tied to environmental conditions, as mosquitoes represent the disease vector. Deforestation, Austin notes, is not a natural phenomenon, but rather results predominantly from human activities, Science Daily reported.

The study builds upon evidence that patterns in climate change, deforestation and other human-induced changes to the natural environment are amplifying malaria transmission.

"Human-induced changes to the natural environment can have a powerful impact on malaria rates," she said.

The analytic research strategy used also allowed the authors to look at the causes of deforestation, in order to have a broader focus on the upstream or human-induced causes of land-use change that impact malaria vulnerabilities.

Results of the study suggest that rural population growth and specialization in agriculture are two key influences on forest loss in developing nations.

Forest loss from agriculture comes in part from food that is exported to more-developed countries, Austin notes.

"In this way, consumption habits in countries like the US can be linked to malaria rates in developing nations."

Deforestation can impact malaria prevalence by several mechanisms, including increasing the amount of sunlight and standing water in some areas. According to the study, in general, increasing standing water and sunlight is favorable for most species of Anopheles mosquitoes that are the key vector of malaria transmission. Austin hopes her research could help facilitate changes in agricultural practices.

"Leaving some trees and practicing more shade and mixed cultivation, rather than plantation agriculture, which involves clear-cutting forests, could help mitigate some of the harmful impacts," she said. Nearly 130 million hectares of forest—an area almost equivalent in size to South Africa—have been lost since 1990, according to a recent report by the Food and Agriculture Organization of the United Nations.