A health worker administers the polio vaccine to a baby beside temporary tent accommodation. Photo courtesy of WHO.
Four-year-old Pooja lives with her family in a jhuggi – a makeshift shanty made of corrugated iron – on a construction site on the outskirts of Kolkata, where her father has been working for the past few months. The settlement is crowded with temporary workers and their families living in sheds and slum dwellings in and around the buildings that are under construction. They don’t have access to toilets or safe drinking water. Pooja’s father’s work is precarious. Once the construction at this site is completed, he and his family will pack up their few possessions and move on, setting up home wherever he can find work.
“Children of migrant workers often miss out on routine and supplementary immunization,” says Dr. Nata Menabde, the World Health Organization (WHO) representative to India. “They are less well vaccinated compared to children living permanently in one place, so they dilute population immunity when they move into high-risk areas.”
Population, or “herd” immunity, occurs when a sufficient proportion of the population is immune to a particular infectious disease. In the case of polio, immunity is provided by vaccination.
As India moved towards eliminating polio, cases of the disease continued to be detected among migrant communities in otherwise polio-free states. Genetic sequencing of the virus showed that migrant populations were sustaining the transmission and transmitting the poliovirus into these areas, thus threatening eradication efforts.
With support from WHO India’s National Polio Surveillance Project, the Government of India launched a strategy to improve reach to these migrant populations.
The first challenge was to track the people that needed to be reached. WHO India worked closely with the health authorities to develop a plan to locate migrant populations and incorporate them into immunization plans.
Each primary health center was made responsible for identification and mapping of migratory/mobile settlements in its area. Doctors enlisted the help of auxiliary nurse midwives, community health workers, social health activists and polio vaccinators to walk through their areas to identify and map pockets of migratory populations and estimate the number of households. This information was then used to plan targeted polio vaccination campaigns.
The strategy identified more than 400 000 high-risk settlements, including urban slums and migrant settlements at construction sites and around brick kilns, as well as other nomadic sites such as migratory fishing villages.
“These are some of India’s most underserved, marginalized people,” says Dr. Sachin Rewaria, training focal person at WHO Country Office for India. “Their living conditions put them at risk of many health problems, yet they are not on the radar for any health services. Some of the children had never received any vaccinations in their lives.”
The intensive mapping formed the basis for targeted polio vaccination campaigns over the next few years. Teams of vaccinators were deployed to visit 125 to 150 households per day in these settlements. Since children often accompany their parents to work, the vaccinators had to make early morning or evening visits to the settlements, when children were most likely to be around.
“Now that India is polio-free, we are using the learnings from polio to ensure that these children receive routine immunization as well,” says Dr. Rakesh Kumar, joint secretary of the Ministry of Health and Family Welfare, government of India.
In 2013, the government held four special immunization weeks across the country, which aimed to provide routine immunizations to identified migrant communities.
Routine immunization plans now include these high-risk sites and outreach routine immunization sessions are organized frequently because there is such a high turnover of families.
“The legacy of the polio eradication campaign is that India now has the know-how and operational skill to reach every child with essential health interventions, no matter how marginalized and remote they are,” says Menabde.