Brote epidémico de hepatitis A relacionado con una guardería.

The aim of this study was to describe an outbreak of hepatitis A in a family group which extended to a day care center and to the families of the children attending the same and to determine the risk of acquiring the disease based on exposure to one or several sources of infection. The temporary distribution of the cases and the rate of hepatitis A in the population at risk were analyzed. The risk of acquiring hepatitis by exposure to one or more sources of infection was studied by logistic regression, calculating the odds ratio and the confidence interval of 95%. Initiation of the outbreak was in May 1996, in a 25-year-old male and finalized in November, having affected 63 people. The rate of global attack was of 12% and the risk of infection 18-fold greater (CI 95% = 5.4-61.8) in those exposed to more than one source of infection than in those exposed to only one source and 3.5-fold greater (CI 95% = 1.2-9.9) in the group from 15 to 29 years of age than in those under 14. The massive administration of immunoglobulin was useful to control the hepatitis in the day care center and in the school. The size of this epidemic of hepatitis A was due to its occurrence in a population little exposed to the virus. The greatest involvement was observed in young adults, with person to person transmission and the greater risk of acquiring hepatitis A on exposure to several sources of infection characterizing the outbreak. The possible usefulness of designing prevention strategies with the vaccine should be considered.