[Seroprevalence of Q fever among the adult population of Lanzarote (Canary Islands)].

Q fever is an endemic zoonosis in the Canary Islands. In 1986, we detected, in a pilot study, residual antibodies of the infection in 3% of the population from Lanzarote. In 1989, we performed a new study in order to assess seroprevalence of Q fever among the adult native population from the island. We studied 390 human serums obtained from an statistically representative sample. Age ranged from 30 to 64 years. Out of 390 serums, 196 (50.25%) were obtained from men and 194 (49.74%) from women. The serological technique used was the fixation of complement using Coxiella burnetii antigens in phase II. Titres equal or higher than 1/8 were considered positive. No statistically significant differences were observed with regard to seroprevalence rates considering sex, age, nor living in or outside the island's capital city. However, when dividing the island's territory in three areas (north, centre and south), and assessing independently their respective seroprevalences, we observed relatively higher seroprevalences in the furthest areas (13.3% in the north and 13.5% in the south) than in the central area (4.7%), although only the higher seroprevalence in the south reached statistical significance when compared with the mean prevalence. Probably, these observations indicate that, although Q fever is extended all over the island, it is a more frequent infection in rural areas of Lanzarote, at the north and the south, than in the central area, where the main urban areas are located.