| Abstract: | ![]()
Between 1990 and 1994 in Africa, the percentage of children administered 3 doses of oral polio vaccine by 12 months old has fallen to about 80%. Any polio eradication program is successful when circulating oral polio vaccine (OPV) supplants wild polio viruses. Thus, any unimmunized children will grow up without encountering any wild virus. As the pool of unimmunized children grows, the chance of an imported wild virus circulating and causing an epidemic increases, as occurred in the recent epidemics in Holland and Oman. The wild virus is still circulating in Africa (e.g., Namibia in 1993, 53 paralyzed children). Immunization of all children and the reporting of every polio case are needed to achieve polio eradication. Even though 98% of children were immunized with 3 doses of OPV in a town in India, several children still became infected with the polio virus. When 5 doses of OPV were administered, no more cases of polio emerged in the town. In the environs of the town, the intensive polio control program reduced the number of cases from more than 1000 to 36 between 1987 and 1994. The program consists of a network of more than 450 reporting agents based in primary health care centers, hospitals, and clinics (public and private sectors). Despite program staff's hard work, several surveys did not find all reported cases and found several unreported cases, indicating the difficulties encountered by a polio control program. Few studies of polio in Africa are published, yet thousands of polio cases occur annually in Africa. Civil war, famine, and many refugees make it more difficult to control polio in Africa. These situations facilitate the spread of diarrheal diseases. Political commitment, ability, and funds are needed to vaccinate all children and maintain surveillance for at least 10 years in order to eradicate polio. Days of tranquility are needed in conflict zones in Africa to allow workers to distribute OPV. |
