Measles Outbreak Propagated by Children Congregating at Water Collection Points in Mayuge District, Eastern Uganda, July–October, 2016

Abstract
Background On 12 October, 2016 a measles outbreak was reported in Mayuge District, eastern Uganda. We investigated the outbreak to determine its scope, identify risk factors for transmission, evaluate vaccination coverage and vaccine effectiveness, and recommend evidence-based control measures. Methods We defined a probable case as onset of fever (≥3 days) and generalized rash, plus ≥1 of the following: conjunctivitis, cough, and/or runny nose in a Mayuge District resident. A confirmed case was a probable case with measles-specific IgM (+) not explained by vaccination. We reviewed medical records and conducted active community case-finding. In a case-control investigation involving probable case-persons and controls matched by age and village, we evaluated risk factors for transmission for both cases and controls during the case-person’s likely exposure period (i.e., 7–21 days prior to rash onset). We estimated vaccine effectiveness (VE) using the formula: VE ≈ (1-ORprotective) × 100. We calculated vaccination coverage using the percentage of controls vaccinated. Results We identified 62 probable case-persons (attack rate [AR] = 4.0/10,000), including 3 confirmed. Of all age groups, children < 5 years were the most affected (AR = 14/10,000). The epidemic curve showed a propagated outbreak. Thirty-two percent (13/41) of case-persons and 13% (21/161) of control-persons visited water-collection sites (by themselves or with parents) during the case-persons’ likely exposure period (ORM-H = 5.0; 95% CI = 1.5–17). Among children aged 9–59 months, the effectiveness of the single-dose measles vaccine was 75% (95% CI = 25–92); vaccination coverage was 68% (95% CI = 61–76). Conclusions Low vaccine effectiveness, inadequate vaccination coverage and congregation at water collection points facilitated measles transmission in this outbreak. We recommended increasing measles vaccination coverage and restriction of children with signs and symptoms of measles from accessing public gatherings.
Description
The research article is about investigation of measles outbreak to determine its scope, identify risk factors for transmission, evaluate vaccination coverage and vaccine effectiveness, and recommend evidence-based control measures.
Keywords
Disease outbreaks, Measles, Risk factors, Uganda
Citation
Majwala, Robert Kaos Nakiire, Lydia Kadobera, Daniel Ario, Alex Riolexus Kusiima, Joy Atuhairwe, Joselyn Annet Matovu, Joseph K. B. Zhu, Bao-Ping, 2018. Measles outbreak propagated by children congregating at water collection points in Mayuge District, eastern Uganda, July–October, 2016. BMC Infectious Diseases, 18:412. https://doi.org/10.1186/s12879-018-3304-5