RESUMO
The purpose of this report is to describe the results of virological surveillance of acute flaccid paralysis (AFP) in Democratic Republic of Congo (DRC), a war-torn country. A total of 3658 stool samples were collected from patients with AFP in provinces under government control and processed as recommended by WHO. The number of specimens tested increased from 32 in 1997 to 2471 in 2001 as the national epidemiologic surveillance program for AFP improved. The national reference laboratory accredited in 1999 was appraised on the basis of the annual rate of non-polio enterovirus isolation which rose from 10% in 1999 to 20% in 2001 and by the percentage of lab results reported within 28 days which rose from 50% in 1999 to over the 80% threshold required by WHO in 2001. From 1997 to 2001, 68 strains of wild poliovirus were isolated including 52 type 1 strains, one type 2 strain and 15 type 3 strains. Most cases of poliomyelitis (81%) reported between 1997 and 2001 involved children aged 0 to 5 years. Only 12% of cases involved children aged 6 to 14 years and 3% involved young adults. Sixty-seven percent of the 45 poliomyelitis patients with documented vaccine status had received 0 to 3 doses of oral poliovirus vaccine (OPV). Fifteen children (33%) developed the disease despite having received more than 4 required doses of OPV. Since 1997 three provinces of DRC, ie., Bas-Congo, Kinshasa city and Nord-Kivu, have been free of wild poliovirus. In 2001 wild poliovirus circulation had been stopped throughout the country thanks to implementation of routine immunization and especially of the national immunization days (NIDs) program.