NEW DELHI: The World Health Organization reports that for the first time in history, India has been without a single case of polio for one year. WHO says this momentous achievement boosts its global campaign to wipe polio off the face of the earth.

WHO says an entire year has passed in which no child in India has been paralyzed by polio. The last case recorded was that of a two-year-old girl in the state of West Bengal on January 13, 2011.

WHO calls this achievement particularly significant, as India always has been considered the toughest place on earth to stop the polio virus. This is due to a combination of factors, including a poor health system and a large migrant community, compounded by high population density and poor sanitation.

Sona Bari is external relations officer for WHO’s Global Polio Eradication Initiative. She welcomed this milestone, but noted it is not the end of the road for India. Rather, she said, it is the start of a process.

“The next few weeks will be nail-biting weeks as we wait for the data on the last 12 months to come in. Every stool sample from a suspected case of polio, every sewage sample will have to test negative," said Bari. "But, when that happens, India will no longer be considered polio endemic. And, this map that the WHO puts out every month will have India un-shaded for the first time in history.”

Bari explained that India will be considered polio-free if no case of polio is detected in the next six weeks. After that, if no cases of polio are found in India for three years, she noted the whole WHO region of South-East Asia will be certified polio-free, providing an important push for the end of polio.

When WHO launched its Global Polio Eradication Initiative in 1988, 350,000 children every year were paralyzed or killed by this crippling disease. That number fell to 620 cases reported in 16 countries in 2011.

Now that India has stopped the transmission of the wild poliovirus, only three polio endemic countries remain - Nigeria, Pakistan and Afghanistan.

Bari said the political and civil instability in these countries are posing enormous challenges for polio eradication.

“Pakistan and Nigeria in particular are on a precipice and it is an emergency right now to stop polio there. The governments are extremely conscious of this. But, as you just pointed out, they have a lot on their plate right now," said Bari. "Cases are rising in both those countries. In Afghanistan, cases have spread outside of the southern regions or the southern part of the country. So all three are a cause for concern.”

On a more optimistic note, Bari said India’s success in stopping polio transmission frees up resources that now can be spent on polio- eradication measures in the three remaining endemic countries.

WHO reports an alarming increase in the number of polio cases in Pakistan and Afghanistan in 2011, with Pakistan recording 192 cases and Afghanistan 76 cases. And, it notes poliovirus from Pakistan re-infected China, which had been polio-free since 1999.

In Africa, WHO says active polio transmission continues in Nigeria, which had 52 cases last year, in Chad and in the Democratic Republic of Congo. Outbreaks in West and Central Africa also occurred in the past 12 months.

Despite the success in India, WHO officials warn against complacency. They say the spread of polio in Africa shows that as long as polio exists somewhere, it remains a threat everywhere.