Polio outbreak in Algeria: epidemiological, virological and vaccinational aspects.

During a poliomyelitis outbreak (October 1983) in El Oued territory (Algeria) 28 cases were diagnosed. All the patients were under 4 years old. The ratio of females to males was 0.33. No deaths occurred during this epidemic. 25 of the 28 polio cases were diagnosed by cell culture and 81% were polio type 1. The epidemiological survey established that the epidemic was due to the insufficiency of vaccination coverage, since the consumption of antipolio vaccine in the epidemic area had dropped by 25% from 1982 to 1983. 7 of the 28 polio cases had been given at least 3 injections of vaccine at the correct intervals. 5 of 8 vaccine samples from the epidemic area had an insufficient titre of polio type 1. These observations showed that the nature of the vaccine, whether killed or live virus, was less important for controlling poliomyelitis than providing medical and sanitary facilities to ensure good vaccination coverage.