Tick Burdens on Peromyscus leucopus Rafinesque and Infection of Ticks by Borrelia spp. in Virginia

The emergence of Southern Tick-Associated Rash Illness (STARI) questions the validity of reported Lyme disease (LD) cases throughout the southern United States. Acute symptoms are identical, and an efficient method of diagnosis is currently unavailable, with the cause(s) in question. The etiologic agent of LD, Borrelia burgdorferi, is transmitted by Ixodes scapularis (Black-legged Tick), while Amblyomma americanum (Lone Star Tick) is known to carry B. lonestari, the bacterium associated with cases of STARI. Peromyscus leucopus (White-footed Mouse) is a very efficient reservoir for these bacteria and tolerant of their vectors. We sampled small (<3 ha) and large (>3 ha) forest patches in Virginia for tick densities, burdens, and infestation rates by collecting ticks by drag sampling and from mice. We also tested ticks for infection by Borrelia. Although mouse density was greater in small patches, tick densities, burdens, and infestation rates did not differ with patch size. B. burgdorferi was not detected in any tick species, but 3.4% of nymphal and 5.9% of adult Lone Star Ticks removed from vegetation were infected with B. lonestari.