Gates Foundation Using GPS to help Eradicate Polio in Nigeria
(ED: Following is an excerpt from Bill Gates’ annual letter on the progress on the Gates Foundation. In this section, the rubber meets the road for explanations about how Internet Medicine is helping to locate children in Northern Nigeria by GPS, rather than depending on inefficient hand maps)
Polio eradication is a top priority for the foundation, a primary focus for me, and a powerful example of the importance of accurate measurement. Starting in 1988, organizations including the U.S. Centers for Disease Control and Prevention, Rotary International, UNICEF, and the World Health Organization, along with many countries of the world, agreed to the goal of eradicating polio. Targeting an explicit goal focused political will and opened purse strings to pay for large-scale immunization campaigns that led to very rapid progress. By 2000, the virus had been wiped out of the Americas, Europe, and most of Asia.
The number of global polio cases has been under 1,000 cases for the last two years, but getting rid of the very last few cases is the hardest part. For some diseases like smallpox-which was visible on the skin-you can track where the cases show up and focus on vaccinating children in those areas. However, polio takes weeks to confirm, and over 95 percent of people infected with the polio virus never develop symptoms-so they can spread the virus without anyone realizing it. That’s why it’s called “silent transmission.” In order to stop the spread of infections, health workers have to vaccinate nearly all children under the age of five multiple times a year to achieve the necessary immunity thresholds in polio-affected countries. It’s estimated that this threshold is 80 to 95 percent in the parts of Africa and Asia that still have polio. Achieving consistent coverage levels to reach these thresholds requires timely, accurate, local measurement so you can see where you are falling below the threshold, figure out what is wrong, and fix it.
Last January, after years of battling the disease, India celebrated a full year without a single case of polio. Most people expected India to be the most difficult place to eliminate polio because of its densely crowded urban areas, huge rural areas in the North, poor sanitation, large mobile populations, and over 27 million children born every year-more than in all of sub-Saharan Africa -that need to be vaccinated. Stopping the circulation of the virus everywhere in the country was the eradication initiative’s biggest accomplishment in the past decade.
There are now just three countries that have never eliminated polio: Nigeria, Pakistan, and Afghanistan. I visited Northern Nigeria four years ago to try to understand why eradication is so difficult there. I saw that routine public health services were failing: Fewer than half the kids were getting vaccines regularly, and there were no reliable figures for how many children lived in each area. Also, the normal process of quality monitoring done as part of each polio campaign was not working. Statistics about the quality of coverage varied greatly. We decided we needed to invest heavily in another layer of quality monitoring to understand what was going wrong. This involved picking random locations on the map and randomly checking children in those places to see if they had been vaccinated. The work required specially trained staff working independently of the people implementing the vaccination campaigns. That impartiality was crucial.
One huge problem the polio program found was that many small settlements in the region were missing from vaccinators’ hand-drawn maps and lists documenting the location of villages and numbers of children. As a result, children weren’t getting vaccinated. Often villages on the border between two maps weren’t assigned to any team. To make matters worse, the estimated distance between villages was sometimes off by miles, making it impossible for some vaccinators to do the job they were assigned.
To fix this, the polio workers walked through all high-risk areas in the northern part of the country. Step by step, they explored these areas and spoke with people, adding 3,000 communities to the immunization campaigns. The program is also using high-resolution satellite images to create even more detailed maps. And since the new maps show the true distances between settlements, managers can now allocate vaccinators efficiently by giving them a full day’s work but no more.
Another problem was that some teams were simply not going to the places they were assigned to go. To help address this, the program is piloting the use of phones equipped with a Global Positioning System (GPS) application for the vaccinators to carry. Tracks are downloaded from the phone to a laptop at the end of the day so managers can see the route the vaccinators followed and compare it to the route they were assigned. This helps ensure that areas that were missed can be revisited so children are not left unprotected from polio.
The Nigerian government and its partners will need to keep working closely to adjust tools and approaches like these to measure coverage in Northern Nigeria more accurately. But progress is definitely being made, and more children are being reached.