Malaria linked to deforestation.Two studies conducted in South America's Amazon forest show that greater incidence of malaria malaria, infectious parasitic disease that can be either acute or chronic and is frequently recurrent. Malaria is common in Africa, Central and South America, the Mediterranean countries, Asia, and many of the Pacific islands. in newly settled frontier regions is related not just to the increase in human numbers, but to changes in the landscape itself. Over a year, various researchers collected mosquitoes at 56 sites in states of deforestation deforestation Process of clearing forests. Rates of deforestation are particularly high in the tropics, where the poor quality of the soil has led to the practice of routine clear-cutting to make new soil available for agricultural use. along a new road that cuts through the Amazon in northeastern Peru. The scientists counted how often the insects landed on humans at each site. Their results, published in the January issue of the American Journal of Tropical Medicine tropical medicine, study, diagnosis, treatment, and prevention of certain diseases prevalent in the tropics. The warmth and humidity of the tropics and the often unsanitary conditions under which so many people in those areas live contribute to the development and and Hygiene, reveal that the bite rate from Peru's main malaria-spreading mosquito mosquito (məskē`tō), small, long-legged insect of the order Diptera, the true flies. The females of most species have piercing and sucking mouth parts and apparently they must feed at least once upon mammalian blood before their eggs can , Anopheles Anopheles: see mosquito. darlingi, was nearly 300 times greater in areas cleared for logging, ranching, and other human activities than in areas with less ecological ecological emanating from or pertaining to ecology. ecological biome see biome. ecological climax the state of balance in an ecosystem when its inhabitants have established their permanent relationships with each alteration. "By dramatically changing the landscape, we are tipping the balance in a way that is increasing the risk of malaria transmission," says senior author Jonathan Patz, a professor at the University of Wisconsin-Madison's Nelson Institute for Environmental Studies. [ILLUSTRATION OMITTED] A report in the February 14 issue of the Proceedings of the National Academy of Sciences The Proceedings of the National Academy of Sciences of the United States of America, usually referred to as PNAS, is the official journal of the United States National Academy of Sciences. pointed to similar links between malaria and deforestation. The study, conducted by a different research team in Brazil's Amazon, attributes heightened malaria risk to the increase in standing water that comes with tree-clearing and other ecosystem changes in the early stages of human settlement. New pools of water create ideal egg-laying environments for A. darlingi, the scientists note. However, once agriculture and urban development are better established in frontier regions, this breeding habitat declines and malaria transmission rates fall. The Amazon research aims to inform efforts to better manage malaria outbreaks, and also confirms the importance of close collaboration between the health and conservation communities. Since 1980, more than 50 million hectares of Amazon forest has been lost, an area roughly the size of Thailand. |
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