The composition of the vertebrate host community has been proposed to influence the prevalence and genetic makeup of B. burgdorferi, the Lyme disease agent. Higher host diversity shall reduce B. burgdorferiprevalence in ticks according to the ‘dilution effect’ hypothesis. Higher host diversity is also expected to increase pathogen diversity, if different hosts act as ‘niches’ for different strains of the pathogen (‘multiple niche polymorphism’ hypothesis)
We have a unique opportunity to determine whether these hypothesis are upheld by comparing B. burgdorferi infection prevalence and genetic diversity on Block Island, RI – a species-poor host community almost exclusively composed of white-footed mice, and mainland sites in Mansfield, Lyme and North Stonington, CT, where all host species are present. Understanding what drives B. burgdorferi genetic diversity is important for public health because B. burgdorferi strains differ in their ability to infect and cause disease in humans.