Validity of measles mortality data using hospital registers and community surveys

Background. Case-fatality rates (CFR) for measles cases have previously been reported to be higher in hospital than in community studies. Methods. Data on measles morbidity and mortality obtained in community investigations of measles outbreaks in two rural districts in Kenya were compared to data from the same time period on measles morbidity and mortality in children hospitalized with measles in the respective district hospitals. Results. The CFR were found to be considerably lower in the respective district hospitals, 1.7 and 2.1%, than in the community surveys, 8.0% and 9.4%, respectively (relative risk [RR] 0.17, 95% confidence interval [CI] 0.10-0.30, and RR = 0.20, 95% Cl : 0.05-0.81). Conclusions. Hospital-based studies of the CFR in measles infection are not representative of measles mortality in the community. It may be misleading to use hospital data in measles control surveillance systems. Further studies are needed of the mortality after discharge of hospitalized measles cases.