[An epidemic outbreak of measles in a rural area].

OBJECTIVE

Analysis of an outbreak of measles among a partially vaccinated school population: the epidemiology, the effectiveness of the control measures and the efficacy of the vaccine (EV).

DESIGN

A descriptive study and cohorts study.

SETTING

Primary Care in the borough of Sant Andreu de la Barca.

PATIENTS AND OTHERS PARTICIPANTS

The school population of Sant Andreu de la Barca.

MEASUREMENTS AND MAIN RESULTS

The outbreak lasted three months and twenty days, with 95 cases overall. The most affected age group was form 4 to 10. 8.4% presented complications. Children were infected at school in 87% of the cases. The overall infection rate of the population between 0 and 15 was 2.4%. 36% of the cases had been correctly immunized and 43% were preventable cases. Vaccine coverage contacts was 67%. 84% of the susceptible contacts were vaccinated. Immunization status and immunization age of 323 out of 500 pupils was studied for the EX analysis. Global EV was 66% (42-80), 58% (13-80) for those immunized, between 12-14 month of age and 71% (43-85) for those immunized after the 15 month of age.

CONCLUSIONS

In order to eradicate the autoctonous measles an increase in immunization coverage, an improvement in the epidemiologic surveillance, and in the outbreak control measures are needed.