During April through September 1990, 399 military personnel who originated from either Fort Chaffee, Arkansas (n = 236) or Fort Wainwright, Alaska (n = 163) were studied during maneuvers in tick-infested areas at Fort Chaffee. Study subjects completed a questionnaire and had pre- and post- maneuvers serum specimens analyzed for antibodies to several rickettsial and ehrlichial agents and to Amblyomma americanum (lone star tick) salivary gland proteins (anti-tick saliva antibodies [ATSA], a biologic marker of tick exposure). Military rank/grade and home station were associated with pre- maneuvers ATSA seropositivity by enzyme-linked immunosorbent assay (ELISA). Fort Wainwright personnel were more likely to show at least a 50% increase in ATSA levels, compared with subjects from Fort Chaffee, from the pre- to the post maneuvers specimen (adjusted odds ratio [AOR] = 2.7, 95% confidence interval [CI] = 1.2-6.1). Subjects from Fort Wainwright who did not report use of bed netting were at an increased risk of post-maneuvers ATSA seropositivity (AOR = 4.1, 95% CI = 1.5-11.5). In contrast, subjects from Fort Chaffee who did not report tucking pants into socks were at increased risk of post-maneuvers ATSA seropositivity (AOR = 2.8, 95% CI = 1.1-7.1). Subjects from Fort Chaffee who reported an attached tick bite during maneuvers were more likely to be ATSA-seropositive in the post-maneuvers specimen (AOR = 2.5, 95% CI = 1.2-5.2). Western blot assays revealed large differences in tick salivary gland proteins that were recognized on the post- maneuvers specimen among three randomly selected individuals, and small differences within a single individual who reported a tick bite during maneuvers, comparing pre- and post-maneuvers specimens. The ATSA ELISA seropositivity was not associated with seroconversion to the tick-borne infectious agents.
ASJC Scopus subject areas
- Infectious Diseases