Using Polio GIS Maps to Increase Coverage during Mass Immunization Campaigns in Northern Nigeria

Abstract Background. Historically, vaccinators struggled to reach all settlements during mass polio campaigns in northern Nigeria because of poor micro plans. This made it difficult to attain the high immunization coverage necessary to interrupt transmission of polio virus in the region. The objective of this study was to devise a means to reach all settlements - Built-Up Areas (BUAs), Small Settlements (SSAs), and Hamlet Areas (HAs) - visible on satellite imagery and thereby significantly increase the overall coverage during mass polio immunization campaigns.Methods. The procedure by which geographic information system GIS drawn maps can be used to improve immunization coverage is presented, along with the extent to which the maps increase immunization coverage when incorporated into team micro plans in northern Nigeria. The method involves training on map comprehension to relevant health workers and vaccination campaign or Immunization Plus Days (IPDs) personnel - who are then able to use the GIS Ward maps to create clusters of settlements, roughly equal in population, commensurate with the total number of vaccination teams allocated to the ward. The maps were then used to guide IPDs personnel in providing polio immunization services to all households in the ward during the January 2019 mass polio immunization campaign. The study area was a distinct and homogeneous geographical area called Horserizum Ward in Hong Local Government Area (LGA) of Adamawa state, Nigeria. The study population was comprised of all resident households or members of the communities (totaling 19,698 persons by the recent local census) in the Ward.Results. At the conclusion of the January campaign, the number of settlements in the Ward unreached by health workers (as shown by the GIS dashboard, www.vts.eocng.org) was compared to previous polio immunization campaigns when no GIS maps were used to guide vaccination activities. Results revealed an immunization coverage for hamlet areas HAs (which is the main settlement type where coverage needed to be improved) of 82% (for January 2019 campaign) versus 43% during the previous campaign held in December 2018.Conclusions. The results were statistically significant (P< 0.0000001, t = 5.175.) and we conclude that, using GIS maps to guide vaccination activities (GIS micro planning) has a very significant positive impact on immunization coverage, especially in rural, hard-to-reach, or scattered settlements.