Brote de tos ferina con elevada tasa de ataque en niños y adolescentes bien vacunados / Outbreak of whooping cough with a high attack rate in well-vaccinated children and adolescents

Introducción La tos ferina es una enfermedad reemergente. Describimos la investigación de un brote de tos ferina y las medidas de control adoptadas. Métodos Se reconstruyó el evento a través de un estudio longitudinal de incidencia. Además de los casos notificados, se realizó una búsqueda activa a partir de la lista de asistentes a las colonias a través de llamadas telefónicas. A todos los casos se les aplicó la encuesta epidemiológica, se confirmó sus antecedentes vacunales con la historia clínica informatizada y se les propuso la obtención de muestras para confirmación analítica. La descripción del brote se realizó a través de la curva epidémica, las tasas de ataque, el riesgo relativo, la prueba de tendencia lineal por edades y la cobertura vacunal. Resultados De los 30 casos que se diagnosticaron 22 (73,3%) correspondían a los integrantes de las colonias. En éstas, la tasa de ataque fue del 21,8%, del 26,7% entre los niños y preadolescentes respectivamente, aumentando linealmente con la edad. El 86,4% de este último grupo estaban correctamente vacunados incluyendo la quinta dosis a los cuatro-seis años de edad. El 90% de los casos del brote fueron detectados a partir del estudio minucioso de los primeros casos y las llamadas telefónicas a los asistentes a las colonias. Conclusiones La búsqueda activa de casos permitió el estudio de un brote de tos ferina con elevada tasa de ataque en niños y preadolescentes y elevada cobertura vacunal y la aplicación de medidas de control que contribuyeron a la detención del brote (AU)

Introduction: Whooping cough is a re-emerging disease. We describe the investigation of an outbreak of whooping cough and the measures of control adopted. Methods: The event was reconstructed through a longitudinal study of incidence. In addition to the notified cases, an active search from the list of those who attended summer camps was made through telephone calls. An epidemiological survey was applied to all cases; vaccination history was confirmed with computerised clinical history and the obtaining of samples for analytical confirmation was proposed. The description of the outbreak was made through the epidemic curve, the attack rates, the relative risk and the linear trend by ages and the vaccination coverage. Results: Of the 30 cases that appeared, 22 (73.3%) were among the members of the summer camps. In these, the attack rate was 21.8%, 26.7% among the children and adolescents increasing linearly with the age. The large majority (86.4%) of this last group were correctly vaccinated, including the fifth dose at the age of 4-6 years. Through the meticulous study of the first cases and the telephone calls to those who attended the summer camp, 90% of the cases of the outbreak were detected. (.. )(AU)

[Outbreak of whooping cough with a high attack rate in well-vaccinated children and adolescents]. / Brote de tos ferina con elevada tasa de ataque en niños y adolescentes bien vacunados.

INTRODUCTION: Whooping cough is a re-emerging disease. We describe the investigation of an outbreak of whooping cough and the measures of control adopted. METHODS: The event was reconstructed through a longitudinal study of incidence. In addition to the notified cases, an active search from the list of those who attended summer camps was made through telephone calls. An epidemiological survey was applied to all cases; vaccination history was confirmed with computerised clinical history and the obtaining of samples for analytical confirmation was proposed. The description of the outbreak was made through the epidemic curve, the attack rates, the relative risk and the linear trend by ages and the vaccination coverage. RESULTS: Of the 30 cases that appeared, 22 (73.3%) were among the members of the summer camps. In these, the attack rate was 21.8%, 26.7% among the children and adolescents increasing linearly with the age. The large majority (86.4%) of this last group were correctly vaccinated, including the fifth dose at the age of 4-6 years. Through the meticulous study of the first cases and the telephone calls to those who attended the summer camp, 90% of the cases of the outbreak were detected. CONCLUSIONS: The active search of cases allowed an outbreak of whooping cough with a high attack rate to be studied in children and adolescents with a high vaccination coverage, and the application of control measures that contributed to stop the outbreak.