title: The prevalence and incidence of clinical and asymptomatic Lyme borreliosis in a population at risk.
abstract: A past history of clinical Lyme borreliosis and the 6-month incidence of clinical and asymptomatic Lyme borreliosis was studied prospectively in a high-risk population. In the spring, blood samples were drawn from 950 Swiss orienteers, who also answered a questionnaire. IgG anti-Borrelia burgdorferi antibodies were detected by ELISA. Positive IgG antibodies were seen in 248 (26.1%), in contrast to 3.9%-6.0% in two groups of controls (n = 101). Of the orienteers, 1.9%-3.1% had a past history of definite or probable clinical Lyme borreliosis. Six months later a second blood sample was obtained from 755 participants, 558 (73.9%) of whom were seronegative initially; 45 (8.1%) had seroconverted from negative to positive. Only 1 (2.2%) developed clinical Lyme borreliosis. Among all participants, the 6-month incidence of clinical Lyme borreliosis was 0.8% (6/755) but was much higher (8.1%) for asymptomatic seroconversion (45/558). In conclusion, positive Lyme serology was common in Swiss orienteers, but clinical disease occurred infrequently.
authors.affiliation: Department of Rheumatology, University of Berne, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Fahrer
authors.forename: S M
authors.initials: SM
authors.lastname: van der Linden
authors.forename: M J
authors.initials: MJ
authors.lastname: Sauvain
authors.forename: L
authors.initials: L
authors.lastname: Gern
authors.forename: E
authors.initials: E
authors.lastname: Zhioua
authors.forename: A
authors.initials: A
authors.lastname: Aeschlimann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D001096:Arachnid Vectors; D001733:Bites and Stings / Q000150:complications; D015748:Borrelia burgdorferi Group / Q000276:immunology*; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D015994:Incidence; D008193:Lyme Disease / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012044:Regression Analysis; D011795:Surveys and Questionnaires; D013987:Ticks
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G