Measles-Rubella Positivity Rate and Associated Factors in Pre-Mass and Post-Mass Vaccination Periods: Analysis of Uganda Routine Surveillance Laboratory Data

Toward 2019, Uganda experienced an extensive outbreak of measles and rubella. The Uganda National Expanded Programme on Immunization implemented a mass measles-rubella vaccination campaign aimed at halting the ongoing transmission. This study determined the changes in the disease burden thereafter. We conducted a retrospective cross-sectional study on measles-rubella positivity and its associated factors in Uganda using 1697 case-based surveillance data for 2019 and 2020 stratified into two dispensations: prevaccination and postvaccination campaigns. Statistical tests employed in STATA 15 included chi-square, Fisher’s exact, and binomial tests. Measles positivity rates in the period before and after the mass immunization campaign were 41.88% (95% CI: 39.30–44.51) and 37.96% (95% CI: 32.81–43.40), respectively. For rubella, the positivity rate in the precampaign season was 21.73% (95% CI: 19.61–23.99) and in the postvaccination season was 6.65% (95% CI: 4.36–10.00). Binomial tests indicated that postcampaign positivity rates were significantly lower than the precampaign rate for measles (p=0.003) and rubella (p