What is polio and in which countries does it still occur?

Polio, or poliomyelitis, is a highly contagious viral disease that affects the nervous system and in severe cases can cause paralysis. The poliovirus is spread primarily by the fecal-oral route, often through contaminated water or food.

There are three types of polioviruses: type 1, type 2 and type 3. Vaccination has led to a dramatic reduction in polio worldwide, but the disease has not yet been completely eradicated. Most people who become infected with the poliovirus do not show any symptoms. When symptoms do occur, they can range from mild flu-like symptoms to severe neurological complications such as acute flaccid paralysis (in less than 1% of those infected), which leads to permanent muscle weakness and sometimes permanent disability.

Thanks to global vaccination campaigns led by organizations such as the World Health Organization (WHO) and the Global Polio Eradication Initiative (GPEI), polio has almost been eradicated. However, there are still a few countries where polio is endemic or has recently experienced outbreaks, such as Afghanistan, Pakistan, some countries in Africa and Southeast Asia, and the Middle East, such as Gaza.

Recent outbreaks in Gaza or other countries are mainly due to insufficient vaccination and living conditions that make it difficult to isolate people with polio.

Source: https://www.who.int/health-topics/poliomyelitis#tab=tab_1

Author: Prof. Dr. Dirk Devroey - Latest update: 2024-07-30 - Copyright: Clinifacts 2025