BACKGROUND: The last case of polio associated with wild poliovirus (WPV) indigenous to the Democratic Republic of the Congo (DRC) was reported in 2001, marking a major milestone toward polio eradication in Africa. However, during 2006-2011, outbreaks associated with WPV type 1 (WPV1) were widespread in the DRC, with >250 reported cases. METHODS: WPV1 isolates obtained from patients with acute flaccid paralysis (AFP) were compared by nucleotide sequencing of the VP1 capsid region (906 nucleotides). VP1 sequence relationships among isolates from the DRC and other countries were visualized in phylogenetic trees, and isolates representing distinct lineage groups were mapped. RESULTS: Phylogenetic analysis indicated that WPV1 was imported twice in 2004-2005 and once in approximately 2006 from Uttar Pradesh, India (a major reservoir of endemicity for WPV1 and WPV3 until 2010-2011), into Angola. WPV1 from the first importation spread to the DRC in 2006, sparking a series of outbreaks that continued into 2011. WPV1 from the second importation was widely disseminated in the DRC and spread to the Congo in 2010-2011. VP1 sequence relationships revealed frequent transmission of WPV1 across the borders of Angola, the DRC, and the Congo. Long branches on the phylogenetic tree signaled prolonged gaps in AFP surveillance and a likely underreporting of polio cases. CONCLUSIONS: The reestablishment of widespread and protracted WPV1 transmission in the DRC and Angola following long-range importations highlights the continuing risks of WPV spread until global eradication is achieved, and it further underscores the need for all countries to maintain high levels of poliovirus vaccine coverage and sensitive surveillance to protect their polio-free status.
BACKGROUND: The last case of polio associated with wild poliovirus (WPV) indigenous to the Democratic Republic of the Congo (DRC) was reported in 2001, marking a major milestone toward polio eradication in Africa. However, during 2006-2011, outbreaks associated with WPV type 1 (WPV1) were widespread in the DRC, with >250 reported cases. METHODS: WPV1 isolates obtained from patients with acute flaccid paralysis (AFP) were compared by nucleotide sequencing of the VP1 capsid region (906 nucleotides). VP1 sequence relationships among isolates from the DRC and other countries were visualized in phylogenetic trees, and isolates representing distinct lineage groups were mapped. RESULTS: Phylogenetic analysis indicated that WPV1 was imported twice in 2004-2005 and once in approximately 2006 from Uttar Pradesh, India (a major reservoir of endemicity for WPV1 and WPV3 until 2010-2011), into Angola. WPV1 from the first importation spread to the DRC in 2006, sparking a series of outbreaks that continued into 2011. WPV1 from the second importation was widely disseminated in the DRC and spread to the Congo in 2010-2011. VP1 sequence relationships revealed frequent transmission of WPV1 across the borders of Angola, the DRC, and the Congo. Long branches on the phylogenetic tree signaled prolonged gaps in AFP surveillance and a likely underreporting of polio cases. CONCLUSIONS: The reestablishment of widespread and protracted WPV1 transmission in the DRC and Angola following long-range importations highlights the continuing risks of WPV spread until global eradication is achieved, and it further underscores the need for all countries to maintain high levels of poliovirus vaccine coverage and sensitive surveillance to protect their polio-free status.
Authors: P M Oostvogel; J K van Wijngaarden; H G van der Avoort; M N Mulders; M A Conyn-van Spaendonck; H C Rümke; G van Steenis; A M van Loon Journal: Lancet Date: 1994-09-03 Impact factor: 79.321
Authors: Mary M Alleman; Kathleen A Wannemuehler; William C Weldon; Jean Pierre Kabuayi; Felly Ekofo; Samuel Edidi; Audry Mulumba; Albert Mbule; Renée N Ntumbannji; Tiekoura Coulibaly; Nadine Abiola; Minlangu Mpingulu; Kassim Sidibe; M Steven Oberste Journal: J Infect Dis Date: 2014-11-01 Impact factor: 5.226
Authors: Hugo Kavunga Membo; Aaron Mweene; Serge Alain Sadeuh-Mba; Justin Masumu; Riziki Yogolelo; Norbert Ngendabanyikwa; Eddy Sokolua; Fred Sagamiko; Edgar Simulundu; Steve Ahuka; Jean Jacques Muyembe Journal: Pan Afr Med J Date: 2016-06-22
Authors: Nischay Mishra; Terry Fei Fan Ng; M Steven Oberste; W Ian Lipkin; Rachel L Marine; Komal Jain; James Ng; Riddhi Thakkar; Adrian Caciula; Adam Price; Joel A Garcia; Jane C Burns; Kiran T Thakur; Kimbell L Hetzler; Janell A Routh; Jennifer L Konopka-Anstadt; W Allan Nix; Rafal Tokarz; Thomas Briese Journal: mBio Date: 2019-08-13 Impact factor: 7.867