[Incidence and characteristics of Q fever in a community habitat]

Q fever is more common in our country than is usually thought, as shown by the diagnostic incidence curve, which approached an exponential rather than lineal function. Sixty cases were diagnosed between 1985 and October 1989. The disease predominated in middle aged males. The suspect epidemiologic contacts did not have any significance. Q fever was more frequent during autumn. Its usual clinical presentation was pneumonia (75%), commonly associated with a flu-like syndrome. Liver was commonly involved (66.6%), although in a mild degree. One of the patients had chronic Q fever, with granulomatous and hepatic, but not endocardial, involvement. The diagnosis was based on seroconversion detected by indirect immunofluorescence. As a rule, the course of the disease was favorable independently from therapy.