Polio eradication initiative
Polio is one of a small limited number of diseases that can be eradicated. The reasons why polio can be eradicated are:
- polio only affects humans, and there is no animal reservoir
- an effective and inexpensive vaccine exists, called Oral PolioVirus (OPV)
- immunity against polio is life-long
- the virus can only survive for a very short time in the environment
The Polio Eradication Initiative (PEI) is a global program with the target of a polio free world by the year 2005. In the African region, the transmission of poliovirus is limited to restricted areas, but the ease with which the virus could be transmitted puts all countries at risk. For the African region to be certified as polio free, there must be no detection of wild poliovirus and an appropriate surveillance system for three consecutive years.
Ethiopia has achieved tremendous progress in its Polio Eradication Initiative activities since it commended in 1996. OPV coverage rates have increased appreciably (from less than 400,000 children in 1996 to more than 14 million in 2001) leading to reduced transmission of the virus. Since January 2001, no wild poliovirus has been identified in Ethiopia and the country has been categorised as an area with low transmission. However, difficult access, security problems and migration mainly due to harsh weather conditions and cross border economic activities remains a big challenge to increased OPV coverage and good AFP surveillance in many parts of the country. Good quality SIAs aimed at reaching the last pockets of wild poliovirus have therefore become a key strategy to maximise the gains achieved so far in PEI and finally kick out the virus from Ethiopia.
Polio SIAs in Ethiopia dates back to 1996, when the first SNIDs were conducted in selected major urban centres. In 1997 and 1998, NIDs were conducted using the fixed posts strategy. House-to-house immunisation was conducted for the first time in Afar, Somali and Beninshangul-Gumuz regions during the 1999 NIDs. The 2001 NIDs was the first nationwide house-to-house polio campaign. The progressive improvement in the number of vaccinated children under 5 years, from 8 million children in 1998 to 14 million children in 2001, and the reduction in zero dose from 24% in year 2000 to 2% in 2001 indicate impressive improvement in the quality and reach of the program. Vaccine wastage has also improved, with the rates reducing from about 22% in 2000 to 10% in 2001.
The strategies used within the Polio Eradication Initiative are i) routine immunisation, ii) supplementary immunisation activities (SIAs), iii) disease surveillance and iv) mop-up campaigns.