Using Polio GIS drawn maps to increase immunization coverage during mass immunization campaigns in northern Nigeria

Background . Before now, reaching all settlements by vaccinators during mass polio campaigns was a big challenge in northern Nigeria consequent of poor micro plans. This made the attainment of very high immunization coverage which is necessary to interrupt transmission of polio virus in the region difficult. The objective of this study was to devise a means to reach all settlements (BUAs, SSAs, Has) visible on satellite imagery and significantly increase the overall coverage during mass polio immunization campaigns. Methods . We provide the procedure by which geographic information system GIS drawn maps can be harnessed to improve immunization coverage. We also show the extent to which the maps increase immunization coverage when used to draw vaccination team micro plans in northern Nigeria. The method simply involves the provision of training on map comprehension to relevant health workers (IPDs personnel) followed by the demarcation of the ward polio GIS drawn maps into clusters of settlement areas – commensurate with the total number of vaccination teams allocated to the ward. The maps were then employed 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 of Adamawa state, Nigeria and all resident households or members of the communities (totaling 19,698 persons by the recent local census) in ward was the study population. 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 of 82% (for January 2019 campaign) versus 43% during the previous campaign held in December 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.


Introduction
The history of mass polio campaigns (Immunization Plus' Days or IPDs for short) dates as far back as 1988 when the world health assembly declared a plan for polio eradication (https://www.who.int/news-room/detail/25-05-2017). Before then, the disease had ravaged the globe with a burden of over 350,000 paralyzed polio victims every year (https://www.who.int/news-room/fact-sheets/detail/poliomyelitis). The World Health Organization (WHO) provided 2 main strategies as a method of freeing the world completely of polio: namely immunization (of which there are several types) and acute flaccid paralysis AFP surveillance (http://www.emro.who.int/polio/strategy/). Using these strategies, there has been remarkable reduction in the number of polio cases worldwide with the disease virtually nonexistence in most countries. Indeed, the only remaining polio endemic countries on the globe as of today (year 2019) according to the WHO are Pakistan, Afghanistan and Nigeria (polioeradication.org/polio-today/polio-now/this-week/). The Nigeria polio problem is a composite of several interwoven factors. These include: noncompliance to immunization, insecurity and vaccination team attitude. Noncompliance to immunization refers to households that are averse to immunization and these abound in the country, particularly in the northern region (Abdulaziz Mohammed et al., 2014). In this part of the country, there still exists many who do not believe in immunization.
Consequently, even when presented with vaccines by health workers going house to house during mass polio campaigns, they do not allow their children to be vaccinated. Hence 4 their young children are at a very high risk of polio infection, and as a result the region has found it difficult to interrupt transmission of polio.
Also, in large swaths of the northern region, communal clashes (either herdsmen versus farmers or clashes of ethnic origin) together with armed banditry and terrorism have rendered many communities inaccessible to vaccination teams (WHO, Adamawa state January 2019 IPDs). Pundits argue that until all children trapped in inaccessible communities (settlements) are served polio vaccination, transmission of polio will continue to thrive in Nigeria.
Vaccination team attitude is the (negative) behavior and performance of health workers who work to support polio vaccination. Many public health experts believe that this may be the greatest problem bedeviling the nation's polio program as it cuts across all regions of the country. Vaccination team attitude can have negative impacts on the program in several ways, including: vaccinators deliberately refusing to visit settlements of assignment during campaigns; vaccinators simply dumping polio vaccine while falsely adding the number of names to the tally sheet corresponding to the number of doses poured away; vaccinators colluding with heads of noncompliant households to mark children as vaccinated (a finger mark with indelible marker) when they do not, in fact, receive the vaccine, and so on and so forth.
Despite these problems, the country has nonetheless recorded and continues to record great success in stopping polio (polioeradication.org/where-we-work/nigeria/). Much of the success achieved in polio eradication initiative (PEI) in the country today is attributable to the intervention of government at all levels and many NGOs directly tackling these problems of noncompliance, insecurity and team attitude. One particularly impactful innovation that perhaps can be called the game changer in the history of polio eradication in Nigeria (https://www.slideshare.net/.../how-the-polio-eradication-effort-in-nigeria-led-to-5 a-quest-for-global-geospatial-reference-data), was conceived and implemented by the The GIS maps revealed faulty micro plans in nearly every Ward across the country. The maps in most cases contain about 5% machine-named SSAa and HAs that are totally unknown to ward micro plan revision teams. It therefore comes as no surprise that despite many rounds of mass polio campaigns in Nigeria, many SSAs and HAs are not reached by vaccinators not because they deliberately refuse to do so (team attitude) but due to a faulty micro plan! Experts agree that once vaccinators are tracked (given phone trackers during mass polio H2H campaigns) and micro plans thoroughly revised such that each and every human habitation in a ward -including machine named SSAs and HAs are assigned locally recognizable names, then, the issue of low immunization coverage due to missed areas (settlements not reached by vaccinators after campaigns) would be over. Such a 7 revision of ward micro plans for mass polio campaigns using GIS drawn maps is what is called GIS micro planning and is the bedrock of this study.

Justification
Analysis of GIS dashboard information over time revealed very poor coverage of settlement areas (particularly hamlet areas) during mass immunization campaigns in Adamawa State. The dashboard uses the presence of GPS tracks in settlements to calculate immunization coverage in a scientific manner & is freely available on the web at: www.vts.eocng.org. Per the dashboard analytics, any settlements without GPS tracks after the conclusion of mass Polio campaigns are classified as "missed" and those with only very few tracks are "poorly covered". In Horserizum ward of Hong LGA for instance, after the conclusion of the December 2018 IPDs, only 80% of villages and 43% of hamlets were reached by vaccinators (the rest were either missed or poorly covered).
Indeed, a total of about 6 hamlet areas (mostly with machine generated names) in the Ward were not covered at all. Machine generated hamlet areas are tiny hamlets (maybe one-man camp or migratory groups) not reflected in the updated ward micro plan list but sighted through satellite imagery and presumed to contain eligible children for vaccination. Despite repeated update of micro plans every round, these hamlet areas have not been identified by any local names hence a difficulty in assigning them to teams for vaccinations. Because resident children in these areas are consistently missed during polio campaigns, they constitute the very high-risk group and are a source of concern to achieving polio eradication in the country. Thus, any innovation to locate and vaccinate these at-risk kids is what the country requires now! Objective The objective of the activity was twofold: Reach all settlements (BUAs, SSAs, HAs) visible on satellite imagery and 2.
Significantly increasing the overall coverage Hypothesis Testing The following hypothesis was tested in the study, all at 1% level of significance;

Scale Of Implementation
The activity was piloted in a rural ward of Hong LGA called Horsherizum with a total of 11 vaccination team members partaking.

Methodology
The production of GIS micro plan for use in the implementation of January 2019 IPDs in Horsherizum ward involves the following steps carried out in a sequential manner viz: 1.
Gathering together of the ward micro plan revision team and the provision of map comprehension skills to them by the WHO cluster consultant.

2.
Providing locally recognizable names to all machine-named SSAs and HAs appearing on the ward GIS drawn map by the ward micro plan revision team members 3. Ward focal person (WFP) demarcates GIS drawn map (using pen marker to make circumscription) into 7 clusters commensurate with the number of house-to-house teams allocated to the ward for the purpose of IPDs implementation. These are called team work areas.

4.
The demarcated team area is further reviewed such that they are approximately of the same total population taking into cognizance the local terrain and distances between settlements within the cluster.

5.
2 days before implementation, each team (headed by a supervisor and containing a vaccinator and a community leader) conducts a tour of the cluster of settlements allocated to her to serve polio vaccination in order to familiarize themselves with the area and to earmark where to begin work on day1 of implementation.

6.
After the logistics tour, team supervisors then divide the assigned cluster of settlements on the ward GIS drawn map into 4 areas -each containing settlements to be visited by the vaccination team members on Days 1-4 of the IPDs. This is the GIS micro plan! Annex A is a copy of Horsherizum GIS micro plan.

7.
Each day of implementation, the team supervisor receives a well-charged phone tracker and returns it at the close of business to be uploaded to the VTS server by a GIS technician from eHealth Africa (one of several global polio eradication partners in Nigeria) to reveal tracks of areas visited.

8.
Final results (after 4 days of activity) are made available on the GIS dashboard at vts.eocng.org, and any settlements still without tracks are considered missed areas (i.e. not visited by vaccination teams).

Data Collection Instruments
The following tools were used to collect all relevant information Android phones (trackers)

GIS dashboard
Latest GIS ward/Team area maps House to house vaccination tally sheets.

Results
The results below were obtained from the study. They were extracted from both the GIS

Results 4: Settlements reached and vaccination coverage, urban areas or BUAs-
obtained from the GIS dashboard at www.eocng.org.

Results 5: Settlements reached and vaccination coverage, small settlement areas
or SSAs -obtained from the GIS dashboard at www.eocng.org. if provided the right motivation! Thus, a simple conclusion that can be drawn from results 2 is that, the micro plans used by teams in Horsherizum ward during January 2019 IPDs allowed them to reach more hamlet areas than that employed in December 2018 (conventional walk through micro plans). But is this 'statistically' significant?
Results 3 indicates that more children and accordingly more doses of vaccines were used in Horsherizum in January 2019 when GIS micro planning was done compared to December 2018 when it was not. This is totally in agreement with immunization coverage seen in results 2 above as the doses of vaccine used must be commensurate with number of children immunized. It is a testimony of good data quality and the fidelity of GIS micro planning in increasing immunization coverage during mass immunization campaigns.
Results 4 suggest that there is no need doing GIS micro planning in order for vaccinators to cover BUAs properly. As a matter of fact, there isn't much difference in immunization coverage when GIS micro plans were used compared to when it was not. As already mentioned in paragraph two above, this is not surprising and only implies that, to cover BUAs properly during IPDs, all that is required is supervision and 'team motivation'.
Indeed, statistically, at 1% level of significance, there's no statically significant difference in the 2 immunization coverage results and we conclude that use of GIS drawn maps for micro planning appears to have no effect on coverage of BUAs.

Conclusions/recommendations
We conclude that when GIS micro planning was undertaken in January 2019, the quality of immunization as measured by immunization coverage -particularly of hamlet areas -was much better than in December 2018 when there was no GIS micro planning. Statistical analysis revealed that there is indeed significant difference between immunization coverage in Horsherizum ward' before and after the study. And that that difference was not due to 'chance'! As majority of Nigeria's underserved population in terms of the provision of health services including immunization live in hamlet areas coupled with the fact that, the settlements most often missed on the GIS dashboard after vaccination team tracking and reported by eHealth Africa (a polio eradication partner in Nigeria) are hamlet 14 areas, any innovation to enhance the ability of vaccinators to find and reach them is pertinent.
It is therefore strongly recommended that GIS micro planning be adopted by WHO Adamawa as a panacea to reaching the high number of hamlet areas reported as missed areas by VTS after rounds of mass Polio campaign in northern Nigeria.

Relevance of study:
The research shall form the way and manner of reaching all human habitations with OPV during IPDs by the GPEI partners (NPHCDA, WHO, NGO partners).