Friday, 25 February 2011

Deforestation and Emerging Infectious Diseases


Many are aware of the environmental consequences of deforestation: trees absorb carbon, and in a world of escalating carbon levels, this natural process is critical to the effort of slowing global warming. What is less well-known about deforestation, is the part it plays in public health for both humans and animals. In this article, Laura Kahn illustrates the role of deforestation in the spread of emerging infectious diseases among both humans and animals. She does this through the story of the Nipah virus outbreak in Malaysia, an event that continues to affect Southeast Asia both directly and indirectly. Kahn outlines the sequence of events that followed a mass deforestation in Malaysia in 1997, the focus of many studies concerning Nipah virus. Being forced from their natural habitat , tropical fruit bats began to feed from fruits in orchards through which pigs roamed and fed. It is through this exposure that an outbreak of the virus spread throughout the newly industrialized pig industry and consequently, to those humans involved in the industry. By 1999, the virus was isolated, the exportation of pigs from Malaysia was halted, about 1 million pigs were killed, 266 people contracted the disease, and 106 died soon after. The outbreak had enormous economic effects on the region, and outbreaks continue to occur, the latest reported being in Bangladesh (February 6, 2011).