Spatial clustering of measles vaccination coverage among children in sub-Saharan Africa

BMC Public Health
http://bmcpublichealth.biomedcentral.com/articles
(Accessed 16 December 2017)

Research article
Spatial clustering of measles vaccination coverage among children in sub-Saharan Africa
Authors: Tenley K. Brownwright, Zan M. Dodson and Willem G. van Panhuis
Citation: BMC Public Health 2017 17:957
Published on: 15 December 2017
Abstract
Background
During the past two decades, vaccination programs have greatly reduced global morbidity and mortality due to measles, but recently this progress has stalled. Even in countries that report high vaccination coverage rates, transmission has continued, particularly in spatially clustered subpopulations with low vaccination coverage.
Methods
We examined the spatial heterogeneity of measles vaccination coverage among children aged 12–23 months in ten Sub-Saharan African countries. We used the Anselin Local Moran’s I to estimate clustering of vaccination coverage based on data from Demographic and Health Surveys conducted between 2008 and 2013. We also examined the role of sociodemographic factors to explain clustering of low vaccination.
Results
We detected 477 spatial clusters with low vaccination coverage, many of which were located in countries with relatively high nationwide vaccination coverage rates such as Zambia and Malawi. We also found clusters in border areas with transient populations. Clustering of low vaccination coverage was related to low health education and limited access to healthcare.
Conclusions
Systematically monitoring clustered populations with low vaccination coverage can inform supplemental immunization activities and strengthen elimination programs. Metrics of spatial heterogeneity should be used routinely to determine the success of immunization programs and the risk of disease persistence.