POLIO TRIO

ONLY THREE COUNTRIES NOW HAVE ONGOING POLIO TRANSMISSION: NIGERIA, AFGHANISTAN AND PAKISTAN

TIP OF THE ICEBERG

Epidemiologists typically detect polio transmission based on reported cases of acute flaccid paralysis (AFP). WHO certifies a country as polio-free if there are no reports of AFP for three years. But AFP is just the tip of the iceberg — one case of AFP indicates substantial underlying polio transmission in a population.

WHAT IS ACUTE FLACCID PARALYSIS

The term is often used to describe a sudden onset, as might be found with polio. Flaccid paralysis occurs when your muscles can no longer contract. Messages sent from the brain to the muscle are interrupted by either infections (like polio), toxins, or from brain and spinal cord injuries.

AFP is the most common sign of acute polio, and used for surveillance during polio outbreaks. Nationwide AFP surveillance is the gold standard for detecting cases of poliomyelitis. The steps of surveillance are: Finding and reporting children with acute flaccid paralysis (AFP) transporting stool samples for analysis.

ISRAEL SHOCKER

There was an epidemiological shock in Israel with the discovery of polio transmission in 2013 because it was the first in that country since 1988. A sewage surveillance system set up in 1989 to detect poliovirus sounded the alarm. The ministry of health launched massive vaccination; none of the infections resulted in paralysis. This helped test the efficacy of the sewage surveillance model, clubbing environmental surveillance data from different parts of the world, to assess how much silent transmission still happens globally. The growing network of disease detectives

Although AFP surveillance remains the gold standard for surveillance for polio, only one in approximately 200 cases of polio actually show symptoms of paralysis.

In endemic areas, environmental surveillance is providing critical supplemental information and data, enabling epidemiologists to tailor the eradication strategies even further.

In other parts of the region, it is proving a critical additional tool to mitigate the risks of a potential virus importation, particularly given the challenges that some countries face, including large-scale population movements, inaccessibility or insecurity.