Each day during Polio supplementary immunization campaigns, the GPS tracks of all vaccination teams are uploaded to a laptop available at the Local Government Area (LGA) level as well as to the Emergency Operations Center (EOC). The tracks are used to generate and compute the geographic coverage by analyzing the tracks with the known list of settlements part of the micro plan.

Locally, all actors of the campaign are able to access the resulting analysis as reports showing tables, charts and maps the same day to make adjustments for the next day activities: Are we progressing well? Which areas could we cover better? Are there any missed or partially covered areas? VTS has become a key tool for tracking and adjusting, in order to cover high-risk areas as well as possible. At the EOC, the VTS automatically computes similar analyses to the ones performed on the local laptops, but includes all the LGAs targeted in order to present a comprehensive view to national authorities and other stakeholders present.

What are the areas covered by VTS?

Each sub-national campaign (SIA or SIPD) targets LGAs in selected States, primarily in northern Nigeria. The VTS process can only be used in the 28 northern-most states where GIS maps are available. Each round, the EOC selects up to 80 high-risk LGAs in these states to be tracked. VTS tracks different types of settlements:

• Urban areas (large settlements or cities with more than 100 residences)
• Small settlements areas (rural villages with 20-100 residences)
• Hamlets areas (clusters of hamlets, each hamlet containing less than 20 residences)

In order to estimate the geographic coverage for these types of settlements, VTS compares GPS positions to the following smallest denominators:

• Urban areas are divided into 50m x 50m grids
• Small settlements are identified as a GPS point with a 75m buffer around it
• Hamlets are identified as a GPS point with a 50m buffer around it
• Hamlet areas gather hamlets within a 200m range from one another

How is the Geographic Coverage estimated?

The Geographic coverage on VTS actually gathers 2 indicators:

• The Cumulative % Visited (for the various settlement types) means the percentage of smallest denominators (i.e. grid squares for urban areas, or buffered points for small settlements and hamlets) that have intersected at least once with a team’s GPS tracks.
• The Total % Visited calculates the average Cumulative % Visited across all settlement types.

GPS positions are collected every 2 minutes, but only GPS tracks that satisfy the following rules are considered valid:

• Urban and small settlements areas:
  • tracks are within the campaign days, and
  • between 5AM and 6PM, and
  • the speed at the capture time is less than 1 meter per second.
• Hamlet areas:
  • tracks are within the campaign days, and
  • between 5AM and 6PM.

What kind of performance reports can I see on VTS?

VTS takes the vaccination teams’ GPS coordinates during campaign days and calculates several types of figures which are included in a number of reports. The most useful reports are the following:

• The Geographic coverage by geographic level, from State to Ward, displays the Cumulative % Visited by settlement type, as well as the Total % Visited by zone. On this report you can drill down from State to LGA to Ward to Settlement, and check reliability of the data according to the percentage of teams that have already reported compared to the number of teams deployed.
• The Missed or partially covered settlements report shows all settlements with a Cumulative % Visited below a certain threshold for partial geocoverage (70% for Urban areas, 50% for Hamlet areas and 100% for Small settlements) and for missed settlements (50% for Urban areas, 1% for Hamlet areas (or 40% for large Hamlet areas) and 1% for Small settlements). It is used every day by all actors in the campaign to adjust next day activities.
• The Chronically missed settlement report helps identify settlements that have been missed or have just been partially covered during several campaigns. The location of these hard-to-reach settlements are loaded to GPS-enabled tablets to help teams find them and vaccinate there.

At the EOC

At the EOC, we use the think-cell software for data analysis and presentation. For further information, visit http://www.think-cell.com/