Deforestation is typically thought of in terms of environmental impact, however there is another deadly cost. When deforestation occurs wildlife is displaced, often these animals carry unfamiliar diseases which they then spread to domestic animals or humans. In 1997 a large number of fruit bats were disturbed by deforestation in Malaysia, within two years the bats had spread Nipah virus to the pigs and pig farmers in the surrounding areas. Another way that deforestation causes the spread of infectious diseases is by increasing the numbers of mosquitoes, the conditions left behind by deforestation are perfect breeding grounds for mosquitoes. Mosquitoes carry malaria, and the number of people infected with malaria have risen when deforestation has gone up.

The U.S. is vulnerable to the spread of mosquito carried diseases and possible infectious diseases crossing the boarder through immigration or travelling citizens. There is no way to stop all of these dangers, but increased resources in ecological conservation will help to mitigate some of the damage that has been done to forested areas. Additionally, the U.S. should invest in research in identifying previously unknown infectious diseases, so that if any of them should make the jump from animal to human, we are better prepared.