Measles and mumps epidemic outbreaks in two geographic areas of Catalonia, 2007

Abstract number: R2421

Sala Farré M.R., Arias Varela C., Recasens Recasens A.

Objectives: In Catalonia, a two-dose MMR vaccination programme for children, free of charge and on a voluntary basis, was launched in 1988. Catalonia is free of indigenous measles since 1999. In 2007 was set the goal of mumps elimination but just in 2007 occurred the most important measles and mumps outbreaks on the last ten years. This report summarizes the differences between measles and mumps cases reported in two geographical areas of Catalonia (Vallès Occidental and Vallès Oriental) with 1.207.464 inhabitants.

Methods: Mumps and measles suspected cases should be reported promptly to the Epidemiological Surveillance Unit. Confirmation of cases requires PCR testing of urine for measles or oral fluid for mumps, or specific IgM serum antibody, or to be epidemiologically linked to a laboratory confirmed case. Epidemiological data and vaccination status had been collected individually from all cases. Correct vaccination status was defined as two doses of MMR vaccine, the first dose after 12 months of age and the 2n dose at least one month later.

Results: Measles outbreak finished in June 2007 with 18 confirmed cases; all of them were not or incorrectly vaccinated; 10 were less than 4 years old; 6 were nosocomial transmitted, 3 on personal staff.

Until September 2007 were reported 83 mumps confirmed cases, predominantly teens; 73% were correctly vaccinated. Most mumps cases coincided with summer vacation. Delay in diagnosis and failure to report in a timely manner occurred in some cases. Despite control effort and highly vaccinated population secondary cases on families and schools were detected but not nosocomial transmission.

Conclusion: The most important differences on epidemiology of the measles and mumps cases were mean age and vaccination status. The majority of mumps cases were correctly vaccinated. Healthcare providers should suspect measles or mumps, dignose by using laboratory testing and report cases immeditly. Furthermore mumps should be suspected independent of vaccination history. When indigenous measles or mumps cases are eliminated the goal must be to interrupt the virus transmission from imported cases.