Epidemiology of tuberculosis in the Gran Canary Island

BACKGROUND: The aim of the present study was to obtain information about tuberculosis (TB) in our area that might contribute to assess the status in Spain. METHODS: A meticulous case finding was carried out during 1988 in all the hospitals of the Gran Canaria island. RESULTS: 214 cases were found (rate 32.2) and 77% were admitted to hospitals. In 160 (74%) the involvement was pulmonary and in 82 (37%) it was extrapulmonary. Mean age was 34 years (range 1-84) and 62% were younger than 40 years. 69% were males. Complete data were obtained in 183 cases (85%). 56% were smokers, 34% alcoholic abusers, 15% drug abusers (35% parenteral) and 4% homosexuals. 26% had some risk factor for TB; 14 of them had been infected by the HIV (8 had AIDS). In 64% there was a diagnostic delay longer than one month. Out of the 214 cases, the diagnosis was made by direct microscopy and/or culture in 110 (51%), by consistent pathological findings in 41 (19%), with some of these studies but with negative results in 35 (16%) and only with clinical and radiological criteria in 28 (13%). 96 (60%) of the pulmonary cases had cavitation. The most common therapeutic schedule (84%) was the recommended 9-month regimen. In 54% no recommendation for the investigation of contacts was made. CONCLUSIONS: In the authors' area, the prevalence of TB is higher than in developed countries. It is more common in middle aged individuals, many diagnoses are still made without bacteriologic studies and in a high number of cases investigation of contacts is not carried out.