The western black-legged tick, Ixodes pacificus: a vector of Borrelia burgdorferi
Burgdorfer, W.; Lane, R.S.; Barbour, A.G.; Gresbrink, R.A.; Anderson, J.R.
American Journal of Tropical Medicine and Hygiene 34(5): 925-930
1985
ISSN/ISBN: 0002-9637 PMID: 3898886 Document Number: 256190
To determine the significance of Ixodes pacificus as a vector of the Lyme disease spirochaete, Borrelia burgdorferi, a tick and spirochaete survey was conducted in northern California and south-western Oregon in 1982-84. Of 1687 adult ticks collected off vegetation, 25 (1.48%) contained spirochaetes. Of 715 ticks from Oregon, 14 (1.96%) were infected whereas 11 (1.13%) of 972 ticks from California harboured spirochaetes. An isolate of 1 of the spirochaetes reacted specifically when treated with monoclonal antibodies to B. burgdorferi. Polyacrylamide gel electrophoresis of a lysate of the isolate showed it to be nearly identical with 2 isolates of B. burgdorferi. Of the 25 infected examples of I. pacificus, 17 had spirochaetes in their mid-gut only; the remaining 8 showed a generalized infection of all the tissues, with mid-gut, central ganglion and ovary or testes showing heavy spirochaetal infections. Decreased immunofluorescent staining reactivity of spirochaetes in tissues other than the mid-gut in 6 of 8 ticks with generalized infection may reflect adverse physiological conditions for the development of spirochaetes in the haemocoel. A tick/spirochaete survey was conducted in northern California and south-western Oregon in 1982-84. Of 1687 adult ticks (Ixodes pacificus) collected off vegetation 25 (1.48%) contained spirochaetes. Of 715 ticks from Oregon 14 (1.96%) were infected whereas 11 (1.13%) of 972 ticks from California harbored spirochaetes.