[Lyme disease in Chile. Prevalence study in selected groups]

BACKGROUND

The prevalence of Lyme disease in Chile is unknown.

AIM

To study the existence and epidemiology of Lyme disease in Chile.

PATIENTS AND METHODS

One hundred eighteen patients with signs or symptoms suggestive of Lyme disease were studied. Antibodies against Borrelia burgdorferi were measured using ELISA and indirect immunofluorescence screening tests. Positive cases were confirmed with ELISA using a purified antigen and Western Blot analysis. Human biological samples and ticks were cultured in BSK-H medium.

RESULTS

Five patients, three with dermatological manifestations and two with facial palsy and other neurological symptoms, had antibodies against Borrelia, measured by ELISA and indirect immunofluorescence. However the presence of IgM antibodies by ELISA using purified antigen, was confirmed in only one case. All sera and cerebrospinal fluids were negative on Western Blot Analysis. No plasma, skin, CSF or thick culture yielded Borrelia

CONCLUSIONS

We could not confirm the existence of Lyme disease in Chile. Positive screening with negative confirmatory test suggests false positive non-specific reactivity or that local Borrelia are antigenically different compared to North American strains.

[Prevalence of fascioliasis in humans, horses, pigs, and wild rabbits in 3 Chilean provinces]

This study sought to estimate for the first time the prevalence of fascioliasis among the rural population in the Chilean provinces of Curico, Talca, and Linares, while also determining the disease's prevalence among horses and wild rabbits in Curico and Talca and among pigs in Talca. From January 1986 to December 1990 a randomly selected sample of 5,861 persons in the three provinces was given intradermal, complement-fixation, double-diffusion, and immunoelectrophoresis tests to detect antibody to Fasciola hepatica. In addition, the ELISA test was used in Talca and Linares. Fecal specimens from horses and pigs were inspected for eggs, and the liver and bile ducts of rabbits were examined histopathologically. The overall prevalence of infection among the human subjects was 0.70%, with rates of 0.6% in Curico, 0.75% in Talca, and 0.71% in Linares. The prevalences of infection in horses, rabbits, and pigs were 13.5%, 6.1%, and 20.6%, respectively. It is estimated that some 2,000 people are infected in the study area. It is recommended that rabbits be taken into account in all control programs for this zoonosis.