Anti-tick saliva antibody: a biologic marker of tick exposure that is a risk factor for Lyme disease seropositivity.
Anti-tick saliva antibody (ATSA) has potential as a biologic marker of exposure to tick bites. In 1989, we conducted a cross-sectional study of 304 outdoor workers in Monmouth County, New Jersey, to evaluate associations between self-reported tick exposure, ATSA status, and Lyme disease antibody status. ATSA levels 1) were correlated with an index of tick exposure on the basis of three self-reported measures of tick exposure and outdoor hours worked per week (p = 0.01); 2) were consistently higher in pet owners compared with persons without pets (p = 0.03); and 3) when examined by duration since last tick bite, peaked at 3-5 weeks after tick bite and then declined (p = 0.06). ATSA levels dichotomized at the 75th percentile (approximately two standard deviations above the mean ATSA optical density of 25 subjects who denied recent tick exposure) were associated with self-reported tick exposure: adjusted odds ratios for high ATSA levels were 4.2 (95% confidence interval (CI) 0.9-18.9) for moderate (versus none) tick exposure and 5.8 (95% CI 1.2-27.2) for high (versus none) tick exposure. Finally, high ATSA levels were associated with Lyme disease seropositivity, with an adjusted odds ratio of 3.2 (95% CI 1.3-7.6). The data suggest that ATSA is a biologic marker of tick exposure that is a risk factor for Lyme disease seropositivity.
Schwartz
B S
BS
Department of Environmental Health Sciences, Johns Hopkins University School of Hygiene and Public Health, Baltimore, MD 21205.
Ford
D P
DP
Childs
J E
JE
Rothman
N
N
Thomas
R J
RJ
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D000818:Animals; D000906:Antibodies / Q000097:blood*; D000907:Antibodies, Bacterial / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001733:Bites and Stings / Q000276:immunology*; D015748:Borrelia burgdorferi Group / Q000276:immunology; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008193:Lyme Disease / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009515:New Jersey; D012044:Regression Analysis; D012307:Risk Factors; D012463:Saliva / Q000276:immunology; D013987:Ticks / Q000276:immunology*
D000906:Antibodies; D000907:Antibodies, Bacterial; D015415:Biomarkers