Outbreak of poliomyelitis in Angola.

Between January and June 1999, 1,100 suspected cases of poliomyelitis were reported in Angola. Poliovirus types 3 and 1 were isolated. Patients' ages ranged from 2 months to 14 years. Of the 588 patients whose vaccine status was known, 58 (9.9%) received >4 doses, 216 (36.7%) received 3 or 4 doses, 178 (30.3%) received 1 or 2 doses, and 136 (23.1%) had no history of vaccination. Civil conflict, economic decline, and crowded areas with scarce sanitation and poor water supply are the most important factors implicated in declining rates of routine vaccination, low population immunity, and intense wild poliovirus transmission. The socioeconomic situation and poor roads have created major difficulties for vaccination and surveillance. The Angolan outbreak has serious implications for the global eradication of poliomyelitis. Surveillance of acute flaccid paralysis remains essential in the assessment of strategies for eradication and interventions to interrupt wild poliovirus transmission.