CROSS-REACTIVITY TO BORRELIA-BURGDORFERI PROTEINS IN SERUM SAMPLES FROM RESIDENTS OF A TROPICAL COUNTRY NONENDEMIC FOR LYME-DISEASE

Reports of Lyme disease from areas where the disease is not endemic ha ve increased. Eighty-six human serum samples from Papua New Guinea (no nendemic for Lyme disease) were examined for the presence of IgG antib odies that recognize Borrelia burgdorferi antigens, using the currentl y recommended two-tiered system of analysis (sensitive ELISA with West ern blot). The percentage of positive tests dropped from 50% to 10% wh en individual negative controls were included in the two-tiered analys is. Positive serum samples failed to inhibit the growth of B, burgdorf eri in culture and did not yield positive reactions in the fluorescent treponemal antibody-absorption test. These characteristics, together with atypical Western blot antigen recognition patterns and the absenc e of known vectors, provide evidence that seropositive results for the se persons are not the result of exposure to B. burgdorferi. Individua l negative controls may minimize false-positive results for serologic tests for Lyme disease, and these tests must be interpreted in the con text of clinical and epidemiologic data.