Study of Tuberculosis Outbreaks Reported in Catalonia, 1998–2002

ObjectiveTo analyze the characteristics of tuberculosis outbreaks declared under vigilance programs in Catalonia.MethodsDescriptive study of outbreaks from 1998 through 2002 for which reports were available. An outbreak was defined as 3 or more associated cases appearing within a year. For 2 health care regions, outbreaks for which there were full surveillance reports with contact tracing were compared to outbreaks identified but which had not been fully reported.ResultsTwenty-seven outbreaks were analyzed. Nineteen (70%) occurred within families. A total of 22 outbreaks were declared upon identification of the true index case and 5 upon detection of secondary cases. The mean annual incidence of outbreaks was 0.40/100000 inhabitants.Most cases were in males 16 to 40 years of age and involved cavitary lesions and a clinically significant diagnostic delay. Twenty-seven outbreaks caused 69 secondary cases.A longer diagnostic delay was seen to correspond to a larger number of secondary cases (P=.08). In the 2 health care regions analyzed, full surveillance reports with contact tracing were issued for 2 of the 14 outbreaks detected (14.4%).ConclusionsTuberculosis outbreaks are common but investigative follow-up is scarce. The size of the outbreak is related to the length of diagnostic delay. Rapid diagnosis, contact tracing, and the issuance of a public health report should be priorities in all outbreaks detected.

ObjetivoAnalizar las características de los brotes de tuberculosis (TB) estudiados por los servicios de vigilancia epidemiológica de Cataluña.MétodosEstudio descriptivo de los brotes de 1998–2002 que disponían de informe epidemiológico. Se definió como brote epidémico cuando había 3 o más casos asociados en un año. En 2 regiones sanitarias se compararon los brotes detectados con los que además tenían informes.ResultadosSe analizaron 27 brotes y la mayoría (n = 19; el 70%) ocurrió en el ámbito familiar. Un total de 22 brotes fueron declarados a partir del caso índice auténtico y 5 a partir de un caso secundario. La incidencia media anual de brotes fue de 0,40/100.000 habitantes. La mayoría fueron generados por varones de 16 a 40 años, con lesiones cavita-rias y un importante retraso diagnóstico. Los 27 brotes provocaron 69 casos secundarios. Se observó que a mayor retraso diagnóstico correspondía mayor número de casos secundarios (p = 0,08). En las 2 regiones sanitarias analiza-das sólo se realizó informe epidemiológico en 2 de los 14 brotes detectados (14,4%).ConclusionesLos brotes de TB son frecuentes pero poco investigados, y el retraso diagnóstico se asoció al tamaño del brote. Se deben priorizar el diagnóstico rápido de los enfermos, el estudio de contactos y la realización de un informe sanitario en cada brote detectado.