Development of the World Health Organization Measles Programmatic Risk Assessment Tool Using Experience from the 2009 Measles Outbreak in Namibia

Abstract

In the World Health Organization (WHO) African region, reported measles cases decreased by 80% and measles mortality declined by 88% during 2000-2012. Based on current performance trends, however, focused efforts will be needed to achieve the regional measles elimination goal. To prioritize efforts to strengthen implementation of elimination strategies, the Centers for Disease Control and Prevention and WHO developed a measles programmatic risk assessment tool to identify high-risk districts and guide and strengthen program activities at the subnational level. This article provides a description of pilot testing of the tool in Namibia using comparisons of high-risk districts identified using 2006-2008 data with reported measles cases and incidence during the 2009 outbreak. Of the 34 health districts in Namibia, 11 (32%) were classified as high risk or very high risk, including the district of Engela where the outbreak began in 2009. The district of Windhoek, including the capital city of Windhoek, had the highest overall risk score-driven primarily by poor population immunity and immunization program performance-and one of the highest incidences during the outbreak. Other high-risk districts were either around the capital district or in the northern part of the country near the border with Angola. Districts categorized as high or very high risk based on the 2006-2008 data generally experienced high measles incidence during the large outbreak in 2009, as did several medium- or low-risk districts. The tool can be used to guide measles elimination strategies and to identify programmatic areas that require strengthening.

Keywords: Elimination; Namibia; measles; outbreak; risk assessment.