Pop Quiz: Disease and deforestation

Forest loss can increase the spread of infectious diseases. Which of these is the most reported tick-borne disease in the US?

Aerial shot of deforestation in the Amazon

© Brent Stirton / Getty Images

You’re right! It’s Lyme disease.

Each year, about 30,000 cases of Lyme disease are reported in the United States, which makes it the most reported vector disease in the country. Lyme disease (a species of bacteria) is passed to humans through ticks that act as vectors—ticks consume the blood of an infected animal (such as a deer) then carry the virus to humans through a bite. The number of people estimated to be diagnosed and treated for Lyme disease is much higher.

Lyme disease is most widespread in the Northeast US, where suburban and exurban development infringe on forests. Research shows that land use, and specifically deforestation, can increase the risk and spread of infectious diseases—including Lyme disease, Ebola and malaria.

Forest fragmentation increases the risk of human exposure to Lyme disease, as wildlife and ticks come in closer contact with humans. Forest loss or fragmentation can also diminish the number of native species living in a certain area as some die off or find new habitats, and more ideal hosts for Lyme disease, like mice, thrive without as many native predators around. With less biodiversity, there is greater risk of human exposure to the disease.

Find out more about the links between deforestation and diseases.