Abstracts Category : Other

The effects of global climate change and habitat modification on the incidence of Lyme disease

by Jason Robart

Lyme disease is one of the most common vector-borne diseases around the world, and the numbers of reported cases are quickly rising. Ixodes ticks are the principal vectors, while Borrelia burgdorferi sensu lato genospecies are the etiological agents of the disease. Climate change, namely global warming, and habitat modification, namely forest fragmentation, are hypothesized to play an active role in this rise in reported cases. An analysis of the primary literature, specifically of studies focused on North America and Europe, was conducted in order to investigate these hypotheses. These studies show that global warming has precipitated a growth in tick populations as well as a northward tick migration, thereby increasing the risk of Lyme disease in emergent and endemic areas alike, for Borrelia spirochetes quickly infect nave tick populations. Furthermore, published studies support the idea that forest fragmentation near human population centers has also increased the risk of Lyme disease in North America, for edge habitats provide suitable conditions for ticks and provide edible vegetation for the animals on which ticks feed, animals which also serve as hosts for B. burgdorferi sensu lato. In contrast, a decrease in fragmentation was found to facilitate tick invasion and establishment in Europe. These studies demonstrate that anthropogenic habitat modifications of varying types can affect ticks and their host populations and increase the risk of Lyme disease near human population centers. However, more research needs to be done to truly understand the different factors that are precipitating the rising number of cases of Lyme disease since there are significant interactions between climate change, habitat modification, and other drivers not examined here. Furthermore, understanding how these drivers function in specific geographic locations can help scientists and public officials tailor local public health measures appropriately. Finally, researchers and pharmaceutical companies must develop a safe, long-lasting, and effective vaccine against the Lyme disease spirochete, for there is not one currently available. Although easily treatable if diagnosed early, Lyme disease can progress to debilitating disease. Unfortunately, the risk of contracting this illness is currently rising and will continue to rise unless effective preventative measures are employed.