Effect of mass measles vaccination on numbers of measles cases: A hospital experience

Abstract

Background. Low measles vaccine coverage has been a characteristic of child health indices in Uganda. A countrywide mass measles vaccination of children from 6 months to 15 years old was undertaken in October 2003 and again in October 2006.
Objective. To describe the effect of mass measles vaccination on the number of measles cases admitted to Mulago Hospital, Kampala, Uganda.
Methods. The study involved a review of documents including ward admission books, patients’ case notes, discharge summaries, measles surveillance records, and laboratory reports. Measles cases admitted during the study period were identified by using the World Health Organization (WHO) clinical case definition of measles during epidemic times but, during non-epidemic periods, the case definition had to be supported by positive testing for measles antibodies. The number
of measles cases admitted before and after each mass vaccination was documented.
Results. Prior to mass measles campaigns, the mean number of measles cases admitted to Mulago Hospital was 120 per month. Seventy-three per cent of the patients were between 9 and 60 months of age. Two weeks after a campaign, the number of measles cases started falling. Four months after each of the mass campaigns, only a few mild measles cases presented; and, for 2 years subsequently, there were no cases severe enough to warrant hospital admission. The number of measles deaths dropped by 54% and 62%, after the first and second mass immunisations, respectively.

Conclusion. Mass measles vaccinations appear to significantly reduce the number of measles cases admitted to Mulago Hospital. However, the retrospective nature of the study and the lack of serological confirmation of the diagnosis of measles might have introduced bias. The results need confirmation by means of prospective studies.