title: Babesia microti: prolonged survival of salavarian piroplasms in nymphal Ixodes dammini.
abstract: We determined how long Babesia microti survive in the salivary glands of nymphal Ixodes dammini. Of those ticks held at 21 C, the proportion with demonstrable piroplasms decreased from 95%, prior to 20 weeks post-larval-feeding (p-l-f), to less than 80% at 42 weeks p-l-f. Similarly, the number of infected acini decreased significantly. Nymphal I. dammini were kept alive for as long as 1 year, by transferring them to 4 C, at 20 weeks p-l-f. The proportion of infected ticks at 52 weeks p-l-f was less than half of the proportion of infected nymphs examined prior to 20 weeks p-l-f, and only 1/6 as many acini were infected. Ultrastructural observations of salivary glands from ticks at 44 weeks p-l-f revealed that B. microti parasites in older ticks remain in the sporoblast meshwork phase; such parasites rarely differentiated into sporozoites. Degenerating parasites containing autophagic vacuoles were also observed in older ticks.
authors: Department of Epidemiology, School of Public Health, University of Alabama Birmingham 35294.
authors: J
authors: J
authors: Piesman
authors: S
authors: S
authors: Lewengrub
authors: M A
authors: MA
authors: Rudzinska
authors: A
authors: A
authors: Spielman
mesh_terms: D000818:Animals; D001403:Babesia / Q000502:physiology*; D006224:Cricetinae / Q000469:parasitology; D005260:Female; D012469:Salivary Glands / Q000469:parasitology; D013987:Ticks / Q000469:parasitology*