Migration caused by climate change in the developing world could affect polio vaccination efforts

From AlertNet:

NEW DELHI, India -- Migration to major cities in India is on the rise, thanks to increasingly unpredictable rains and fluctuating farm income, and is complicating an old battle: that to eradicate polio.

India is one of just four countries - including Nigeria, Pakistan and Afghanistan - that have never managed to eradicate the disease, which paralyzes a share of those who contract it.

India's government and private organizations have waged a long and often innovative effort to change that, and have made dramatic strides in states like Bihar, where improved governance has helped lead to a dramatic drop in cases.

But in a nation with a long history of worker migration, growing climate-related movement threatens to undo some of the gains, particularly since migrants often end up in slums with poor sanitation, where chances for transmission of the virus are high.

The problems facing Parvati Devi (pictured), a mother of three now living in Delhi's slums, suggest what may be ahead for India's polio battle.

Devi strongly opposed leaving her rural home in Tehruli, in India's Uttar Pradesh state, and coming to the city, not least because the trip was difficult for her three young children, the last barely two. She begged her husband to hold on another year.

But 42-year old Ghanshyam Yadav had no choice. His rice crops had failed for the fifth year in a row, thanks to unpredictable rains and a fast-receding water table, he said. An unrelenting money-lender was demanding payment. He had no option but to search for work elsewhere.

"These days livelihood from farming has become as unpredictable as a game of dice," he said, an observation echoed by growing numbers of distressed farmers.

Last November, Yadav and Devi and their children, with 30 other neighboring families, set out together for Delhi, to look for work as daily wage labourers building parts of New Delhi's Jawaharlal Nehru Stadium for the Commonwealth Games, scheduled for October 2010.

Today they live near the west gate of the stadium, in one of a long line of one-room tin-roofed compartments provided for families of workers by four construction companies working at the site.

Devi says the few makeshift toilets provided collapsed after digging commenced for the stadium's water tank. Now most people, including her small children, defecate in the open, along the lanes near the huts or in a garbage dump next to the community's water vat.

Polio eradication officials say such practices encourage the transmission of polio, which is spread by contact with infected feces.

"The maximum spread of polio virus is through the fecal-oral route. A single polio carrier child is a risk to a thousand children around him. Transmission chances are much higher under unhygienic conditions," said Dr Pankaj Bhatnagar of the World Health Organization's National Polio Surveillance Programme (NPSP).

The programme, a joint effort by WHO and the Indian health ministry, records polio data and draws up strategies to wipe out polio in India.

Polio virus lives in the throat and intestines of affected children, and passes to others through contact with the faeces of the infected child. Open defecation can suspends the virus in the air, allowing it to enter the body through nose or mouth, health officials said.

Devi's children have been vaccinated against polio back home in Utter Pradesh. But achieving effective protection requires giving children several rounds of drops. In Delhi, Devi has no idea where to get them.

"We have heard the radio announcing polio day. But unless they come here, how can we give the drops?" she asked.

Back at home, Parvati says, many rounds of vaccination for years now have been unable to finish off the disease and have left some people tired and doubtful about the eradication program.

The government's keenness to vaccinate repeatedly and the huge amount of resources committed to the programme has led to unfounded suspicions that the program has some other hidden agenda.

Back home, there were rumors that the polio drops caused sterility, Devi said, though she and her husband never believed it.

In recent times, communities in Uttar Pradesh where polio still circulates have tried to extract promises of better roads, water connections and other amenities in exchange for allowing polio vaccination campaigns to continue.

Delhi slum dwellers have not gone so far, but many appear to feel little sense of urgency that their children should be vaccinated, in part because they face so many other pressing health and economic problems.

In recent years, all polio cases in Delhi have been among children living in slums, mostly migrants or those living in close proximity to migrants from the endemic states, health officials said.

To help deal with the problem, India's government has set up an innovative tracking system for pregnant women and newborns, designed to ensure the children of migrants get needed polio vaccinations regardless of where they are living at the moment.

Individuals, known as 'informers,' are chosen by district governments to alert field staff when families migrate away from or return to villages.

The informers generally are people with strong local knowledge or influence, including village health workers, large landowners (whose farmhands may move), shopkeepers and close relatives who can provide exact information about new settlement locations.

Besides tracking down migrants in their new locations, vaccinators station themselves at transit points like bus and railway stations, police checkpoints and toll stations, and target temporary shanties at migrant-rich places like isolated brick kilns and construction sites.

Such efforts to halt the migration of the polio virus are crucial if the 'last inch' of polio eradication is to be accomplished, said Dr Sunil Khaparde, a senior health ministry official.

India, which had 741 polio cases in 2009, has seen a dramatic reduction in cases so far this year, with 18 recorded through March 9.

Still, India continues to have one of the highest rates of polio among the four remaining 'endemic' polio countries, according to data from the Global Polio Eradication Initiative, the largest public health initiative in the world. Started in 1988, it is spearheaded by national governments, WHO, UNICEF and other health organizations.

Besides India's traditional polio risk groups - families in Bihar and in western Uttar Pradesh - "since the last few years we are targeting a third polio high risk group - the migrating groups," Khaparde said.

Uttar Pradesh's Ghaziabad district, which adjoins New Delhi, is emerging as a new epicenter for polio in India, with 71 cases reported in 2009, the same number as from the traditional polio epicenter of Moradabad in Uttar Pradesh.

West Bengal, which had been polio-free since 2003, saw one case in 2009 and another in 2010 of the most virulent strain of the disease, genetically linked to the Uttar Pradesh cases.