Can India Stamp Out Polio?
|Our Correspondent||Oct 20, 2011|
Could India, once the world’s ravaged by the polio virus, be on the verge of eradicating the scourge? Only one case has been recorded in 2011, in West Bengal in January.
While many international epidemiologists believe the global polio eradication effort has more or less hit a plateau, they suggest that India may be inching towards succeeding in stopping the transmission of the disease.
There is need for caution, however. This period is crucial if polio eradication is to be truly achieved and subsequently the WHO certification gained. A country must be completely polio-free for three years to gain certification. As India’s Health Minister, Ghulam Nabi Azad, cautioned recently, the occurrence of even a single case during this phase could almost lead to a public health emergency.
India began its polio program in 1995, one of the biggest public health programs the world had seen, with the aim of vaccinating 165 million children. The program was designed to eradicate the virus by 2000, which mostly affects children between the ages of 2 and 5, usually cripples them for life and sometimes causing death. To be declared polio-free, a country must have no new cases for three consecutive years. Subsequent recurrences of the disease pushed back the target date.
The continuing vaccination program is the key. This, along with relentless efforts by the central and state governments, UN agencies like UNICEF and WHO, organizations like Rotary International, and other key partners, have helped to establish the much needed health-seeking behavior from caregivers and parents of children under five.
New cases would not come as a surprise, say many health experts, given the possibility of residual transmission somewhere. But the greatest risk for such transmission seems to have passed.
New polio cases usually rise in August/and September as the monsoon rains from June to September spread sewage and water contaminated by the virus, giving rise to transmission through the oral-fecal route. Although patterns vary, in 2010 there were only a few cases and they peaked in August.
The real sources of polio have been the two northern states of Bihar and Uttar Pradesh, which have stayed “cordoned off” from the rest of the country. Once known for more viruses than anywhere in the world, the two states have not produced or transmitted any new cases within their borders for around a year. Massive vaccination efforts now reach more than 98 percent of children in Uttar Pradesh, and over 95 percent in Bihar.
In most places, 90 per cent coverage is the goal. Pakistan, where polio is spreading, manages only 50 per cent, with the data suggesting that the cases are concentrated near the Afghan border, so the risk of cross-border spread between Pakistan and India remains low. There is also constant regulation along the international border. For instance, a recent public health notification was issued to ensure that all children who may be entering India from Pakistan are immunized.
The intensive polio vaccine coverage in Bihar and Uttar Pradesh has led to high levels of immunity against the remaining strains of polio. In a recently conducted survey, supported by WHO, over 98 per cent of children were found to have antibodies against wPV1 virus, and 77 per cent against wild Polio Virus type-3 (wPV3). With the polio virus eliminated at its source, wild polio virus cases across the country dipped from 741 in 2009 to 42 in 2010 and to just one case in 2011.
The primary source of detection for polio is through cases of acute flaccid paralysis (AFP). It is to be noted that only about one-in-2,000 wPV3 infections result in paralysis, whereas it is one-in-200 for wPV1.
India saw its last type-3 virus around a year ago. This seems to indicate that India has managed to push the wPV3 to a corner. All the six outbreaks in 2009 were fully neutralized, which is why there have been no cases in 2011. Moreover, according to available scientific data, even sewage samples taken from select high-risk areas have not shown the presence of the type 3 virus for over 14 months.
Given India’s high population density and other risk-factors like poor routine immunization, lack of appropriate sanitation and poor hand-washing/hygiene health-behavior, gaps in detection are possible despite the country having an extremely sensitive disease surveillance system in place. While polio surveillance in Uttar Pradesh and Bihar is of unprecedented quality, there are still regions where, theoretically speaking, transmission could persist undetected. In fact, based on given WHO guidelines, an eradication certification is never given until no case is recorded for three years from the last case.
Traditionally, the Indian public health program has been using the trivalent polio vaccination as a part of its routine immunization, which is integrated into the ante-natal health care program. Special polio vaccination drives in select states/districts, as a part of National Immunization Days and so on, have been employing a vaccination strategy with mOPV1 or mOPV3 (monovalent oral polio vaccine for type-1 or type-3 viruses), largely depending on the category of polio virus (wPV1 or wPV3) prevalent in the area.
However, in the last quarter of 2009, it was decided that the national program use the bivalent polio vaccination (comprising OPV1 and OPV3) instead.
Starting early 2010, the program was able to vaccinate children under 5 years with the bivalent vaccine, thus protecting them against both polio viruses. Many health experts credit this strategic use of Bivalent OPV for India being “polio free” since January, a period that includes, significantly, the peak monsoon months.
In efforts of this kind, strategic health communication plays an important role. But it is a complex process given strong beliefs and social norms at the community level, which in turn influence health behavior and practices. The challenge is to address segmented sets of audiences, study varying degrees of prevalent psychological and environmental risk-factors, and then design tailor-made communication packages that promote ownership among local leaders and lead to greater community participation.
In the context of the national eradication program, strategic communication has played a significant role, especially in the at-risk, high-risk and endemic areas of the country. It specifically included addressing communities in high prevalence areas where there is either a refusal or a resistance to adopt the immunization regime. Well orchestrated vaccination operations can be complemented by strategic communication to establish a vital link between people, providers and the projection of key prevention messages.
At a juncture when India is expected to be on the verge of eradicating polio, it may be useful to study the communication strategies deployed so far. Two similar public health challenges – smallpox and HIV/AIDS – both within the gamut of communicable diseases, posed identical challenges for communication strategies. Policy experts would do well to undertake comparative studies on the communication efforts in eradicating polio, small pox and HIV/AIDS, in terms of outreach, behaviour change communication, social mobilisation and advocacy, and then draw the right lessons from the exercise.
It is clear that while 2010-11 saw the consolidation of the polio eradication program, the next three years – till 2014 – will be crucial. This also means focused and intense communication and preventive work, especially with regard to critical risk-factors like poor routine immunization and lack of proper sanitation.
Clearly, there is no room for complacency. India needs to be even more focused on its outreach communication. The goal of complete eradication is within reach. The challenge is to ensure the sustainability of the success achieved so far.
(The writer is a senior UN professional in Strategic Health/Development Communication. Credit: Women's Feature Service)