Prévalence de la paralysie flasque aigue et surveillance environnementale des poliovirus à Kinshasa en République Démocratique du Congo.

Abstract

Poliomyelitis remains a public health concern despite progress achieved through vaccination, due to the persistence of vaccine-derived polioviruses, particularly in areas with low immunization coverage. In the Democratic Republic of the Congo, although the country has been certified free of wild poliovirus, recurrent outbreaks continue to occur, especially in Kinshasa, as evidenced by acute flaccid paralysis (AFP) surveillance and environmental monitoring of wastewater. This descriptive and analytical cross-sectional study, conducted in Kinshasa from January to September 2025, aimed to assess the prevalence of polioviruses among children aged 0 to 5 years with AFP and in wastewater. A total of 186 samples were analyzed, including 93 stool samples from children originating from 13 health zones and 93 wastewater samples collected from 8 municipalities. Analyses were performed at the National Polio Reference Laboratory of the INRB and were based on viral isolation using cell culture (RD and L20B) followed by confirmation through real-time reverse transcription PCR (rRT-PCR). The prevalence of polioviruses among children with AFP was 11.8%, with 81.8% of positive cases occurring in incompletely vaccinated children; however, the association between infection and vaccination status was not statistically significant (p > 0.05). Environmental surveillance revealed an overall detection rate of 6.5%, with a predominance of vaccine-related strains (SL1, SL3, PV2/nOPV2), indicating silent environmental circulation of the virus. These findings demonstrate the persistent circulation of polioviruses in Kinshasa and highlight the need to strengthen immunization coverage as well as epidemiological and environmental surveillance in order to sustainably support polio eradication efforts in the Democratic Republic of the Congo.