PAKISTAN (CNN) - More than a month ago, the public health community celebrated the polio-free certification of Southeast Asia including India, viewed as a hopeful step toward global eradication.
But the euphoria has waned as concerns grow the virus is making a comeback and re-appearing in countries that had previously eliminated the disease within their borders.
Pakistan has seen major challenges in recent years, reporting 80 percent of polio cases this year.
The country faces challenges within its health system including restricted access to its federally administered tribal areas and violence against polio campaign health workers. Vaccine workers have been tortured, shot, bombed, and even have had their family members kidnapped.
"You have disruption of health services, vaccination services are broken where areas are no-go because there is mistrust and health teams are not allowed within the conflict area," said Dr. Zulfiqar Bhutta, who is co-director of The Hospital for Sick Children in Canada and also works in Pakistan. "In that particular circumstance, to imagine that business would be as usual is naïve."
While Pakistan faces hurdles, India's polio program has been lauded as a model for tackling polio.
India's program "was largely internally funded, strongly managed," said Bhutta.
Once considered the hardest place to end polio, India boosted disease surveillance and immunization efforts to vaccinate hard-to-reach communities. To counter rumors and misgivings about the vaccine, social mobilizers, religious leaders and parents were included to increase understanding about immunizations.
In 2014, the World Health Organization confirmed 74 new cases of polio, 59 of them were in Pakistan. Within Pakistan, 46 of these cases have been from its restive Federally Administered Tribal Areas, which is located along the Pakistan-Afghanistan border and retains internal autonomy.
The country with the second highest number of polio cases is Afghanistan, which reported four cases. But all of these are related to viruses that originated from Pakistan, according to the WHO.