Another milestone in polio eradication has been achieved with the eradication of the second type of polio virus. There are three types of polio virus. Although they are different scientifically, the symptoms of these are the same which includes paralysis or sometimes even death. Type2 virus was eradicated before four years and now the WHO has announced the eradication of type 3 virus also. However type 1 is still found in Pakistan and Afghanistan.
Polio affects children below 5 years of age. According to the estimates of WHO, one out of 200 cases results in irreversible paralysis. When paralysis affects the breathing muscles, it eventually leads to death. Polio cannot be cured but children can be protected against the disease by giving vaccination. There has been a 99% drop in wild polio cases since the year 1988. The declaration of eradication of type 2 virus was made in 2015, 16 years after the reporting of last case in India. Type3 virus was detected last in northern Nigeria before seven years. The experts from Global Commission for the Certification of Poliomyelitis Eradication have been watching the patterns of cases to make sure type 3 has been completely eradicated.
The Regional Director of WHO for Africa, Dr Matshidiso Moeti said that though an important milestone has been achieved they could not sit back and relax. He said that communities should be protected through routine immunizations, routine surveillance should be ramped up so that a slightest risk of reemergence of polio can be detected soon and the quality and timeliness of outbreak response must be ensured. He said that their job is not finished until type 1 virus gets eradicated globally. It is now present in Afghanistan and Pakistan only.
There are also instances of vaccine-derived polio which occurs in places of poor sanitation and where there is low vaccine coverage. Vaccine-derived polio virus are currently reported in 12 countries which include Zambia, Togo, Nigeria, Niger, Ghana, Ethiopia, Chad, Democratic Republic of Congo, Cameroon, Central African Republic, Benin and Angola.