The Lyme Disease Debate

Host Biodiversity and Human Disease Risk

Sharon Levy


Environ Health Perspect. 2013;121(4):a120-a125. 

In This Article

Reaching Understanding

It has been written that without understanding the fundamental processes underlying the role of biodiversity in ecosystem functions and services, "attempts to forecast the societal consequences of biodiversity loss, and to meet policy objectives, are likely to fail."[49] Issues of both habitat type and landscape scale are important in understanding the ecology of zoonotic disease, be it Lyme disease or any other disease that has been cited as an example of the dilution effect. Bb is a forest-associated species, and the risk of human infection increases with proximity to forested landscapes. Within forests, however, biodiversity may buffer risk. Hantavirus shows a parallel pattern: It's most prevalent in rodent communities of low diversity, but it's a pathogen of rural areas. Despite low biodiversity in cities, you won't catch hantavirus there.[7]

"Lyme disease is a poster child for the dilution effect," says Wood. "Ecologists have extrapolated from research on Lyme to argue that biodiversity conservation can provide disease control for many other zoonotic diseases. But if ecologists are going to suggest using biodiversity conservation to protect human health, we should at a minimum be sure that it won't make the problem worse. The intense controversy shows we're not sure of that—even for Lyme."