Parasitism by Ixodes Dammini (Acari: Ixodidae) and Antibodies to Spirochetes in Mammals at Lyme Disease Foci in Connecticut, USA1

Abstract

Wild and domestic mammals, collected during 1978–1982 from areas endemic for Lyme disease, were examined to determine prevalence of Ixodes dammini and were surveyed for antibodies against different strains of spirochetes. More than 66% of 656 small and medium-sized hosts had I. dammini immatures or adults; parasitism ranged from 21.4% of 28 Eastern Chipmunks to 84.2% of 38 Virginia Opossums. Indirect immunofluorescence (IF) tests detected antibodies to spirochetes in 197 (20.5%) of the 961 sera analyzed. Seropositivity for White-footed Mice, Virginia Opossums, Eastern Chipmunks, Raccoons, dogs, deer, and Gray Squirrels ranged from 10.3 to 50%. Samples of an additional 442 mammalian sera, representative of areas in western Connecticut where I. dammini is rare, were negative. Four strains of spirochetes isolated from I. dammini and feral mammals in northeastern United States reacted similarly in our indirect IF test.