India is polio free, but faces threat of virus from Pakistan

The Centre would tag India polio free on February 11. However, everything is not hunky dory as is being perceived. Or, at least that's what world health organisation (WHO) country head, Dr Nata Menabde, feels, warning us against complacency.

Dr Menabde, who spoke to dna, warned that India still faced the threat of cross-country infection from neighbours like Pakistan and Afghanistan.

Pakistan is still a hotbed for polio infection with the number of cases going up from 58 in 2012 to 92 in 2013. In the case of Afghanistan, the figures for wild polio virus (WPV) cases have actually dropped, from 37 in 2012 to 14 last year. But that's not convincing enough.

India has not reported a single WPV case in the last three years. The last known case was of an 18-month-old girl from West Bengal, in 2011.

According to WHO, for a country to be considered ‘polio-free,’ not a single case must have been reported in it for three years in a row. India fits the bill, but remains vulnerable due to geographical proximity to countries that carry a heavy (viral) load.

In the new millennium, many countries have ensured that polio virus of domestic origin does not infect its population, but up to 49 countries have had polio outbreaks due to ‘import.’

Cross-country ‘import’ or ‘export,’ has remained an area of concern, said Menabde.

“A few years back, virus of Indian origin caused an outbreak in Tajikistan (Asia) and Angola (Africa). These countries had already eliminated it.

“We back track the origin of the virus to the country it belongs by genetic sequencing methods,” Menabde pointed out.

Eleven countries–Bangladesh, Bhutan, DPR Korea, India, Indonesia, Maldives, Myanmar, Nepal, Sri Lanka, Thailand, Timor-Leste—that are in the South East Asia region of WHO, will be declared ‘polio-free’ in March 2014. That will mean four of the six WHO regions would have eradicated the virus.

The two regions that are still plagued by the virus are the East Mediterranean region that includes Afghanistan and Pakistan, and the African region that includes Nigeria.

Annual occurrence and declining trend of polio in India

1970s – 80s – 2, 00,000 cases
1980s – 90s – 50,000 cases
1998 – 1998 cases
2006 – 676
2010 – 42
2011 - 1

Q & A

1.) Pakistan and Afghanistan being neighbouring countries and hot beds of polio, will they affect India’s polio-free status in anyway if cases emerge in India, possibly due to cross country transmission?
Importation of virus from neighbouring countries is a high possibility. Each country declares itself polio free if there are no reported cases of occurrence in three years at a row. WHO later does a formal certification of the region in which the country belongs. WHO has been divided in six regions, African, American, South East Asian, European, Eastern Mediterranean and Western Pacific. India is one of the 11 countries in South East Asian region which will be declared polio-free in March this year. Pakistan and Afghanistan though are placed in Eastern Mediterranean region and will not affect India’s status.

2.) Why have India and Pakistan though being neighboring countries been categorized diplomatically into different regions by WHO?
The intention was to have Pakistan away from India in the Eastern Mediterranean region. It is a matter of political geographical distribution. WHO is one organization and it does not matter in which region do the countries fall. North Korea had requested to be moved to South East Asia Region as they were more comfortable functioning from there whereas South Korea is placed in Western Pacific region.  For instance, as a result of the Palestine-Israel conflict, Israel requested WHO to be moved to the European region, away from Palestine. Governing bodies cannot function with conflicts. Let’s not mix politics with health issues.

4.) What percentage of patients affected with polio virus get disabled as also is there any gradation of disability that a polio patient may suffer from?
I don’t think we have accurate statistics of the number of people currently living with polio. It very often causes paralysis of limbs through nervous system. Also the seriousness with which paralysis strikes is also different. There is no defined gradation of disability though. However, at WHO, it is estimated that there are 780 cases of people living with polio since 1978. It must be noted that polio eradication program is not about tracking people with disabilities but focuses on prevention by conducting surveillance, collection of samples, vaccination campaigns and research on vaccination.

At least four children from India were infected with polio after consumption of oral vaccine. A 9-month old boy from Navi Mumbai became the fourth Indian to get Vaccine Derived Polio. Does that not make oral vaccination unsafe for use?
Oral polio vaccine is a preferred globally as it produces antibodies in blood and intestines thus providing double immunity while injectable polio vaccine (IPV) only produces antibodies in blood stream. IPV on the other hand contains inactivated virus which it means five times higher immunity in blood though it has no immunity in gut. Oral vaccine has  a great significance, five times cheaper. Though, I must say that IPV does not cause vaccine derived polio while OPV can cause the infection. Since 2000, close to ten billion doses of OPV were distributed to 2.5 billion children. Of these, there were twenty outbreaks of oral vaccine derived polio cases in 20 countries.  Total numbers of such incidences is very little compared to public health benefit.

Is that not scary? Aren’t you endorsing oral vaccine inspite of risks involved to children? Even the US has done away with oral polio vaccines due to associated risk and have shifted to injectable polio vaccines. What is the best possible vaccination solution?
By 2016, WHO is looking at introduction of Injectible Polio Vaccine (IPV) all over the world. The Indian government has agreed to use injectible vaccines.  The US did away with oral polio vaccines since 2000 and UK discontinued its use in 2004 due to associated risks. We have had big negotiations with India including expert advisory group to discuss this issues. India is one of major markets and so if India buys into it, the global price of those vaccines will go down. Currently while IPV is priced at 10US$ for ten vials this may reduce to 1US$ for ten vials in India.  It is a challenging process though to adopt IPV for India due to logistical challenges. IPV requires cold chain storage, good sanitary conditions, sterilization during production. However, right now WHO is in a scientific phase of calculating global needs. In India, research has shown that combination of oral and injectible vaccines can provide children better immunity. Immunology is an ongoing research based science. Just now, we don’t have a hundred percent strategy as to what a polio end game means. New evidence of how vaccines work is constantly under review.

What steps should India take to step up its guard against polio?
In India, continuous surveillance is a must. The moment a viral infection is detected in a sample or a patient, it must be quickly identified and killed. Also, India has to have its emergency response plans in place and any complacency will cost it dear. It has to step up cross border vaccination programs. India has already adopted WHO’s travel advisory which advises vaccination for all travelers flying in or out to polio-endemic nations like Pakistan, Afghanistan and Nigeria.