2 MUMPS OUTBREAKS IN RETROSPECT

Two studies are presented. The first one concerns a mumps outbreak in a kindergarten in Geneva in June 1991. Of 26 children, nine (34.6%) go t mumps. Of nine children vaccinated with the Rubini vaccine strain, s even had the disease as opposed to only one of 14 children vaccinated with the Urabe strain. The vaccine efficacy of the Rubini strain was e stimated at 22% with a 95% confidence interval of -10% to 45%. The sec ond study concerns a cluster of 112 mumps patients seen by a pediatric ian in the Bernese Jura region between September 1992 and May 1993. A case-control study was carried out resulting in a vaccine efficacy est imate of 50% with a 95% confidence interval of -19% to 81%. Of the cas es, 51 (45.5%) had been vaccinated against mumps, 50 of them (98%) wit h the Rubini vaccine strain. Of the controls, 30 (61.2%) had been vacc inated, 86.7% of them with Rubini. Methodological problems of case sel ection and their possible effects on the estimated vaccine efficacy ar e discussed. The results of these two sudies have been confirmed by mo re recent investigations. In retrospect, we therefore conclude that sm all studies can serve as early indicators for epidemiological evidence and that they can be finally integrated into a more complete picture.