Improving Polio Vaccination Coverage in Nigeria Through the Use of Geographic Information System Technology

Transcription

1 SUPPLEMENT ARTICLE Improving Polio Vaccination Coverage in Nigeria Through the Use of Geographic Information System Technology Inuwa Barau, 1 Mahmud Zubairu, 2 Michael N. Mwanza, 2 and Vincent Y. Seaman 3 1 National Primary Healthcare Development Agency, Ministry of Health, and 2 World Health Organization, Nigeria Country Office, Abuja, Nigeria; and 3 Bill & Melinda Gates Foundation, Seattle, Washington Background. Historically, microplanning for polio vaccination campaigns in Nigeria relied on inaccurate and incomplete hand-drawn maps, resulting in the exclusion of entire settlements and missed children. The goal of this work was to create accurate, coordinate-based maps for 8 polio-endemic states in northern Nigeria to improve microplanning and support tracking of vaccination teams, thereby enhancing coverage, supervision, and accountability. Methods. Settlement features were identified in the target states, using high-resolution satellite imagery. Field teams collected names and geocoordinates for each settlement feature, with the help of local guides. Global position system (GPS) tracking of vaccination teams was conducted in selected areas and daily feedback provided to supervisors. Results. Geographic information system (GIS) based maps were created for 2238 wards in the 8 target states. The resulting microplans included all settlements and more-efficient team assignments, owing to the improved spatial reference. GPS tracking was conducted in 111 high-risk local government areas, resulting in improved team performance and the identification of missed/poorly covered settlements. Conclusions. Accurate and complete maps are a necessary part of an effective polio microplan, and tracking vaccinators gives supervisors a tool to ensure that all settlements are visited. Keywords. polio; microplan; mapping; GIS; GPS; tracking. In 1988, the World Health Assembly launched the Global Polio Eradication Initiative (GPEI), and in 2012 declared the completion of polio eradication a programmatic emergency for global public health. The virus is still endemic in 3 countries: Pakistan, Afghanistan, and Nigeria. Experts generally agree that Nigeria is a key battleground in the war against polio. Although the country made impressive gains in 2010, reducing the number of cases of wild poliovirus (WPV) infection to 21, from >500 in 2009, the number of polio cases in Nigeria rose dramatically over the next 2 years, totaling 97 and 122 in 2011 and 2012, Correspondence: Vincent Y. Seaman, PhD, Bill & Melinda Gates Foundation, PO Box 23350, Seattle, WA (vincent.seaman@gatesfoundation.org). The Journal of Infectious Diseases 2014;210(S1):S The Author Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please journals.permissions@oup.com. DOI: /infdis/jiu010 respectively. Security issues, religious and sectarian opposition, a decentralized government lacking a strong federal arm, widespread corruption, poor literacy rates, and extreme poverty are all acknowledged to be factors in Nigeria s recent lack of progress. These social, economic, and political issues, however, are complex and will likely not be resolved in the foreseeable future. There are, however, programmatic weaknesses in the polio effort in Nigeria which are amenable to improvements, such as training, planning, supervision, and accountability. Two small pilot studies using global positioning system (GPS) devices to improve the maps used in microplanning (see insert below) and to track vaccination teams were conducted in 2009 and 2010 [1] and are discussed in detail in another article in this issue. These projects demonstrated that GIS technology could potentially improve the quality of microplanning, provide useful information about team performance, and provide tools to identify missed or partially covered settlements (Figure 1). Despite these S102 JID 2014:210 (Suppl 1) Barau et al

2 Figure 1. Comparison of team assignments, using hand-drawn and geographic information system maps. promising results, the GPEI partners in Nigeria the World Health Organization (WHO), the United Nations Children s Fund, and the Centers for Disease Control and Prevention (CDC) and the National Primary Healthcare Development Agency (NPHCDA) lacked the technical expertise and resources to continue the work on a larger scale at that time. In the latter half of 2011, it was apparent that the number of cases of WPV infection in Nigeria was on the increase, compared with Postcampaign monitoring data indicated that many children were being chronically missed, and supervision of vaccination teams and overall accountability in the program needed attention. Bolstered by a large increase in support from international donors, the Government of Nigeria, with the assistance of GPEI partners, initiated a number of interventions to address those areas most in need of improvement, including bringing in thousands of experienced international consultants, revising the microplanning process, establishing an accountability framework, and creating a presidential task force to oversee the entire operation. It was also recognized that accurate maps were needed, especially in northern Nigeria, to support the microplanning process and that tracking vaccination teams would provide a much-needed tool for assessing performance and coverage. In December of 2011, the NPHCDA and its GPEI partners, with support from the Bill & Melinda Gates Foundation, embarked on an ambitious project to address these critical needs by creating geographic information system (GIS) based maps for 8 northern states, which accounted for >75% of the WPV infections in METHODS There are 4 distinct parts to the GIS work in Nigeria: (1) collecting the settlement and administrative boundary data and creating coordinate-based maps (GIS maps) of the target states, (2) integrating the maps into the microplanning process, (3) employing GPS trackers to follow vaccination teams, displaying the tracks on GIS maps to assess coverage, and providing real-time feedback, and (4) implementing a Web-based vaccination tracking system (VTS) dashboard, where the tracking data and geographic coverage can be viewed by local and remote stakeholders. Collecting Settlement Data, Collecting Boundary Data, and Making Maps A thorough survey of the literature and online resources confirmed that official boundaries existed for the 2 highest administrative levels - states and local government areas (LGAs) - and only the major cities were located on existing maps. Boundaries for wards the lowest administrative level and the operational unit for polio microplanning were not available, nor were the names and locations of the majority of the ward settlements. All settlement locations in the 8 target states (Kebbi, Sokoto, Zamfara, Katsina, Kano, Jigawa, Yobe, and Borno) were identified by manual feature extraction of high-resolution, recent satellite imagery (IKONOS imagery, 4-m ground resolution, multispectral, panchromatic, 1-m ground resolution, pan-sharpened; WorldView-I Imagery, 0.5-m ground resolution), and map layers created for Improving Polio Vaccination Coverage in Nigeria JID 2014:210 (Suppl 1) S103

3 Figure 2. Polio vaccination campaign microplanning. the following categories: hamlets, defined as 1 15 residences or compounds grouped together ( point feature); hamlet areas, defined as groups of hamlets within 200 m of one another (polygon feature); small settlements, defined as residences or compounds grouped together and as settlements with >100 residences or compounds that comprise huts and/or mud brick structures and lack a grid layout ( point feature); and built-up areas (BUAs), defined as >100 residences or compounds with metal roofs, grouped together and organized in a grid-like, urban setting (polygon feature). The settlement names and locations are collected by field teams, which consist of a data collector and local guide approved by the village or ward head, by using a GPS-enabled Android telephone with a custom application with the following queries: state name (selected from the drop-down list), LGA name (selected from the drop-down list), ward name (selected from the drop-down list), settlement name (selected from the drop-down list or by entering text; collect coordinates), and points of interest (POIs; health facilities [name and type], schools [name and type], markets [name], mosques/churches [name], water access points, and the village head compound [name and telephone]; collect coordinates for each POI). After all settlements in a ward are visited, the data are uploaded and overlaid on the satellite imagery. Any collected settlement names that do not align with an extracted feature and any extracted features that do not have a collected place name are marked for revisit/validation. A single primary name is selected for every BUA and small settlement feature. In addition, secondary names identifying subdivisions are collected for many BUAs. Naming the hamlet areas is problematic, since they are an artificial construct based on proximity. There are sometimes many names for a single hamlet area, but more often the local guides are unable to provide any names for the hamlet areas. In this case, the unnamed hamlet areas are assigned a so-called machine name (ie, HA-1 ) until a correct local name can be identified. Ward boundaries are created using an automated tool (thiessen polygons; ArcMap, ESRI) to draw a border around all settlements attributed to that ward. To avoid legal or property disputes, the boundaries are referred to as ward vaccination boundaries, and it is continually emphasized that they are operational boundaries, not political boundaries. The ward boundaries are fit to the existing official LGA and state boundaries to facilitate data sharing and analysis. All settlement and boundary data are housed in a versioned geodatabase, using commercially available software (ArcGIS Enterprise, ESRI). Finally, draft maps for microplanning are created and sent to the ward leaders for validation and sign off. Integrating the Maps Into the Microplanning Process Once approved by the ward leaders, maps are printed (both A2 and A3 size) for each ward for use in microplanning. A template for the microplan, including the maps, is also made available via the tracking dashboard Web site (see below). The maps and the S104 JID 2014:210 (Suppl 1) Barau et al

4 templates can then be used by the ward team the ward focal point (WFP), the ward head, and other community elders for the microplanning process. Orientation for this process is conducted through a cascaded training, beginning with the state immunization officers and WHO LGA cluster consultants, who then train the LGA immunization officers and WFPs. On the basis of population and location, all ward settlements are assigned to 1 or more teams on 1 or more days of the 4-day campaign. A detailed description of the microplanning process is available in Figure 2. GPS Tracking, Analysis, and Feedback GPS tracking of vaccination teams is currently conducted in up to 40 LGAs (approximately 400 wards and 4000 teams) per campaign. The highest-risk LGAs are selected for tracking by the national emergency operations center (EOC). A custom data collection application installed on GPS-enabled Android telephones (Etisilat GaGa 3.75G Android 2.2 Smart- Phone) collects a GPS point with a date/time stamp every 2 minutes. Tracking A set of tracking telephones is given to each WFP every morning at the LGA headquarters, who then returns to the ward takeoff point and gives a telephone to each vaccination team as they begin their assigned work. When all teams have completed their daily work plan, the WFP collects the telephones and returns to the LGA headquarters for a daily meeting to review and report on the daily progress. The trackers are collected at this time, and tracks are uploaded to a laptop by a support technician, who provides feedback directly to the WFPs. The tracking data are simultaneously transmitted via a mifi box to the central server at the national EOC in Abuja, which powers the VTS dashboard. Analysis Calculation of geographic coverage is determined as follows (Figure 3). For BUAs, a grid of 100-m squares is overlaid on all BUAs. If a track passes through a grid square, it is counted as having been visited, and the geographic coverage is the percentage of grid squares that are visited. A threshold of 70% is set Figure 3. Calculation of geographic coverage for 3 settlement types. Improving Polio Vaccination Coverage in Nigeria JID 2014:210 (Suppl 1) S105

5 for BUAs, to account for nonresidential areas within the BUA boundary. For small settlement areas, a 75-m buffer is created around each small settlement point to create a small settlement area. If a track passes through the buffered area, it is counted as having been visited. Small settlement areas have a binary geographic coverage (either 0% or 100%) and are assigned a coverage threshold of 100%. For hamlet areas, a 50-m buffer is created around each hamlet point within the hamlet area. If a track passes through the buffered area, the hamlet is counted as having been visited. The geographic coverage is the percentage of hamlets within the hamlet area that are visited. Hamlet areas are assigned a threshold of 50%, to account for unoccupied or nonresidential hamlets (ie, storage huts) and errors in the feature extraction process (ie, rocks or trees appearing to be hamlets). Feedback The uploaded tracks are overlaid on the ward map, which is then printed and given to the WFPs, along with a list showing the cumulative geographic coverage for all ward settlements. The WFP can then determine whether the teams visited all of the assigned settlement according to the microplan and can intervene in the case of poorly performing teams. This process is repeated for the 4 days of the campaign. At the end of day 4, a missed-settlements list is generated to guide the mop-up process on day 5. At the end of day 5, the mop-up tracks are uploaded, and the list is re-run and distributed to the LGA, state, and national supervisors for follow-up. If additional mop-ups are deemed necessary, they are tracked and reported on, using the above process. Tracking Dashboard A Web-based tracking dashboard (available at: org) was created to provide a platform for feedback at the LGA level and also to allow remote users to follow the progress of the vaccination campaign. The VTS dashboard is updated each evening with the tracks from that day and allows stakeholders to visualize geographic coverage at the state, LGA, ward, or settlement level. Tracks for each vaccination team can be viewed on satellite imagery to further evaluate coverage and identify missed areas. The dashboard also allows users to print ward maps, microplan templates, and chronically missed settlement reports. RESULTS Collecting Settlement Data, Collecting Boundary Data, and Making Maps Some difficulties were encountered early in the settlement data collection process as a result of using multiple contractors for the data collection and map creation. This resulted in settlement points with incorrect or missing ward attributes, which Table 1. Administrative Area and Settlement Spelling and Abbreviation Variants LGA in Jigawa State Settlement in Kano State Abbreviations for Unguwar Kirikassama Tsuburi Unguwar Galadima Kirikasama Tsuburri Unguwar G dima Kiri Kassama Tsubure Ung Galadima Kiri Kasama Tsubare Ung/Galadima Kirikissama Tsubari Ung.Galadima Kiri Kissama Tsubburi U Galadima K/Kassama Suburi U/Galadima K/Kissama Suburri U.Galadima K Kassama Subarri... K Kissama Subburi... Kirika Sama Karika Samma Abbreviation: LGA, Local Government Area. ledtomisalignedwardboundaries.wealsofoundthatlocal residents did not always agree on the proper name for a settlement or used a variety of spellings and abbreviations (Table 1). The hamlet areas tend to be in hard-to-reach, remote, rural areas and are often named after a local traditional leader. Thus, a large hamlet area could have 1 or many names, depending on how many distinct groups reside there. This information, while known to the residents of the hamlet areas, is often not known outside the area, making it difficult for others in the ward to know their exact location and extent. Names were found for only 25% of the hamlet areas during the initial data collection but are being continuously updated. Together, these factors led to some initial resistance from the LGA and ward teams, as they quickly noticed settlements with incorrect ward attributes or spelling irregularities. The upside of this was the increased engagement of the WFPs, who seemed to be determined to find errors in the maps. These problems were ultimately resolved by recollecting much of the data, which also led to the inclusion of many nomadic settlements that had not been previously identified. At the time of this writing, GIS maps had been createdanddistributedforall 2238 wards in the 8 target states with the greatest polio burden in northern Nigeria, with identification of > settlements (Figure 4). Integrating the Maps Into the Microplanning Process Beginning in July 2012, as the mapping for each state was completed, ward maps were provided for microplanning for each campaign. However, it was not until September 2013, when maps for all 8 target states had been completed and revised, that formal orientation and training on the use of the maps took place. By December 2013, ward microplanning maps S106 JID 2014:210 (Suppl 1) Barau et al

6 Figure 4. Geographic information system mapped states and cases of wild poliovirus infection in Nigeria. and templates were distributed to all 2238 wards in the 8 GIS states. The resulting microplans included >3000 new settlements, captured all settlements in the wards, and allowed for more-efficient planning of team catchment areas. An example of the microplan template and map is shown in Figure 5. GPS Tracking, Analysis, and Feedback GPS tracking of vaccination teams has been conducted in 6 of the 8 GIS-mapped states since July Because of security and access issues, as of November 2013 no tracking has been done in Yobe, and only 2 LGAs have been tracked in Borno. In the 6 accessible states, a total of 256 tracking events have been conducted, and 99 of the 163 LGAs have been tracked at least once. During this period, >2500 settlements that were initially missed during the 4-day campaigns were identified by the VTS and targeted for mop-up. Figure 6 shows an example of a settlement missed after day 4 that was covered by the mop-up after receipt of feedback from the VTS. During the most recent campaign (in November 2013), >7000 teams were tracked in 40 LGAs in 5 states. Feedback from the VTS identified 140 settlements that were poorly covered or missed and resulted in an additional 5600 children being vaccinated during the mop-up (Table 2). DISCUSSION In addition to the work presented in this article, many other interventions are continuously being implemented to improve the quality of the vaccination campaigns in Nigeria. These include a surge of thousands of technical consultants and advisors to support microplanning and campaign implementation in the field; intensified communications and outreach strategies; increased involvement of local politicians, traditional leaders, and religious leaders; and the establishment of a presidential task force. As a result, it is difficult to measure the impact of specific efforts such as GIS microplanning and vaccinator tracking. However, since the introduction of the GIS work in Nigeria, the number of WPV infections has declined in the accessible GIS-mapped states, whereas new cases have arisen mostly in security-compromised and non-gis states. In 2012, 123 WPV infections occurred in 14 different states, including all of the GIS-mapped states. In 2013, 50 WPV infections have been Improving Polio Vaccination Coverage in Nigeria JID 2014:210 (Suppl 1) S107

7 Figure 5. Example of microplan template and map (Getso ward, Gwarzo LGA). reported in 9 states, only one of which was a GIS-accessible state (Kano). Nearly half the 2013 cases have occurred in the security- -compromised states of Yobe and Borno. Gaining access to these states to conduct vaccination campaigns and implement the VTS will be a major step in the eradication effort in Nigeria. The use of the GIS maps ensures that every settlement is included in the microplan and is assigned to a vaccination team. However, the geographic coverage provided by the VTS does not necessarily equate to vaccination coverage. The VTS cannot verify whether children are actually being vaccinated, it only shows where vaccination teams have or have not visited. Thus, the main value of the VTS is to identify settlements that are not visited, which equates to identification of areas where children are not vaccinated. The feedback provided allows supervisors to identify these missed settlements (and poorly performing vaccination teams) and to make targeted corrective actions. Although a tremendous amount of work has been done, there are still areas that need urgent attention. First, not all maps are fully complete, and minimal tracking has occurred in the security-compromised states of Yobe and Borno, where nearly half of the WPV infections have occurred in While progress has been made in the past year, at least one-third of the LGAs have limited access to vaccination teams. Second, more than half of the hamlet areas still have machine names. While they are included in the microplan, they are often missed by vaccination teams because they do not know the location and/or extent of the area. We hope to address this issue by developing a tablet application that will show a map of the ward and settlements and the current location of the team. It will also provide distance and direction to nearby settlements to enable teams to reach them, vaccinate the children, and collect the correct names for the machine-named hamlet areas. Third, along with an accurate map and microplan, improved supervision is required to ensure that vaccination teams perform their work and truly reach all of the children in their catchment area. This work is being led by the NPHCDA, the WHO, and newly established EOCs in 5 of the northern states and must be maintained if the polio eradication effort in Nigeria is to be successful. S108 JID 2014:210 (Suppl 1) Barau et al

8 Figure 6. Impact of Vaccination Tracking System feedback on mop-up coverage. The GIS mapping and tracking of vaccination teams in Nigeria has clearly improved microplanning and provided valuable feedback in identifying missed settlements, leading to increased coverage and fewer missed children. In addition, areas that have been chronically missed in the past have been identified and are now part of the microplan and can be targeted for special attention. While the impact of this work cannot be easily separated from the many other interventions, we are confident that it has contributed to the overall success of the GPEI in Nigeria in 2013, as evidenced by a >50% reduction in the number of WPV infections nationally from 2012 and an 85% reduction in the number in GIS-accessible states. We are also accumulatinggeographiccoveragedataovermultiplecampaignsthat will enable us to better assess the contributions of the GISbased work. Last, the impact of introducing new technology and building capacity in a developing country cannot be Table 2. State-Level Vaccination Tracking System (VTS) Results of the November 2013 Poliovirus Vaccination Campaign State LGAs Tracked, No. State Geographic Coverage, % LGA Geographic Coverage, %, Range VTS Missed Settlements Covered in Mop-up, No. Total Target Population, No. Borno Kano Katsina Sokoto Zamfara a Total Abbreviation: LGA, Local Government Area. a A total of 6 of 10 wards in one LGA (Maru) were inaccessible due to security concerns. Improving Polio Vaccination Coverage in Nigeria JID 2014:210 (Suppl 1) S109

9 understated. Thousands of Nigerian health workers have now been trained to read GIS-based maps and are beginning to recognize their value in other areas. These include planning for routine immunization activities, logistics support, and cold chain management. In addition, >60 individuals from the NPHCDA, the WHO, and GIS states have been trained in the use of GIS mapping and analysis software (ArcMap, qgis). We are confident that these individuals will carry this work forward and help integrate it into all areas of Nigerian life. Notes Acknowledgments. The Bill & Melinda Gates Foundation, the WHO, and the National Primary Health Care Agency of Nigeria acknowledge the important contributions of Dr Mizan Siddiqi and his team at Phss- Nigeria, Adam Thompson, and Evelyn Castle and the ehealth Nigeria staff, Novel-T Sarl, and the polio project team at ESRI. We thank the field staff from the WHO and NPHCDA and the LGA public health teams, who provided operational support and assistance throughout the project. Financial support. This work was supported by the Bill & Melinda Gates Foundation. Supplement sponsorship. This article is part of a supplement entitled The Final Phase of Polio Eradication and Endgame Strategies for the Post-Eradication Era, which was sponsored by the Centers for Disease Control and Prevention. Potential conflicts of interest. All authors: No reported conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed. Reference 1. Global Polio Eradication Initiative. Nigeria: new technology helps reach more children with life-saving polio vaccine. polioeradication.org/tabid/167/iid/83/default.aspx#sthash.zbuie5el. dpuf. S110 JID 2014:210 (Suppl 1) Barau et al