As World Polio Week came to a close Wednesday, we got a look at the great progress that has been accomplished since 1988 when the forty-first World Health Assembly adopted a resolution for the worldwide eradication of polio.

Image/March of Dimes
Image/March of Dimes

Polio cases have decreased by over 99% since 1988, from an estimated 350,000 cases in more than 125 endemic countries then, to 416 reported cases in 2013. These included only 160 cases in endemic countries; international spread from endemic areas into polio-free areas accounted for the remainder.

In 2014, only 3 countries in the world remain polio-endemic: Nigeria, Pakistan and Afghanistan.

Of the 3 types of wild poliovirus (type 1, type 2 and type 3), type 2 wild poliovirus transmission has been successfully stopped (since 1999).

South East Asia was certified as polio-free in 2014. Prior to that, in 1994, the WHO Region of the Americas was certified polio-free, followed by the WHO Western Pacific Region in 2000 and the WHO European Region in June 2002.

In addition, Oct. 28 was the 100th birth anniversary of Jonas Salk, who developed the first polio vaccine in the 1950s. Columbia University Microbiology professor and long time poliovirus researcher, Vincent Racaniello, PhD posted a Salk tribute on his blog, which features an interview Peter Salk, Jonas Salk’s son.

Poliovirus  Image/CDC
Poliovirus Image/CDC

Despite the celebration, and indeed there is much to celebrate, Pakistan continues to report multiple cases of wild poliovirus 1 (WPV 1) on a weekly basis. According to the Global Polio Eradication Initiative (GPEI), ten new wild poliovirus type 1 (WPV1) cases were reported in the past week in Pakistan. Of these, 4 are from the Federally Administered Tribal Areas (FATA) (1 from North Waziristan, 1 from Frontier Region Bannu and 2 from Khyber Agency); 1 from Zhob district in Balochistan province, previously uninfected in 2014; 1 from Peshawar district of Khyber Pakhtunkhwa (KP) province; and 4 from Sindh province (1 from Khigadap, 2 from Khikorangi and 1 from Dadu, the latter 2 districts were previously uninfected in 2014).

This brings Pakistan’s total number of WPV1 cases in 2014 to 220 compared to 53 in 2013 by this date.