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In Nigeria and West Africa, a cVDPV2 outbreak originating from Jigawa state, Nigeria, continues to spread. In Ghana, cVDPV2 was isolated from an acute flaccid paralysis (AFP) case in Ando-Nyamanu, Chereponi district, Northern Region, bordering Togo. The case was a two-year old girl who had experienced onset of paralysis on 27 July 2019. Stool samples were taken on 27 and 28 July 2019, and sent to the National Polio Laboratory at the Noguchi Memorial Institute for Medical Research for further laboratory investigations. The sample tested positive for cVDPV2 on 17 August 2019. Sequencing of the sample from the AFP case revealed 25 nucleotide differences compared to the reference Sabin 2 and 6 nucleotides, with the closest sequencing match made with an AFP case originating from Jigsaw state, Nigeria from 2018. Earlier, a related cVDPV2 strain had been isolated from an environmental sample, collected on 11 June 2019, from Northern Region in Ghana. Both isolated viruses were linked to an outbreak originating in Jigawa, Nigeria, in 2018. In the past, this same strain had spread within Nigeria, and internationally to the Republic of Niger, Benin, and Cameroon.

The last indigenous wild poliovirus was reported in 2000. This is the first ever reported cVDPV2 outbreak reported in the country.

On 23 June 2019, a vaccine-derived poliovirus type 1 (VDPV1) was isolated from a two -year- old child with acute flaccid paralysis (AFP), with onset of paralysis on 22 May 2019 from Kayin state, Myanmar. Subsequently, on 11 July 2019, a genetically linked VDPV1 was isolated from the same state from a 5-year 6-month-old child with AFP, with date of onset of paralysis on 14 June, and it was classified as circulating VDPV1 (cVDPV1) on 12 July 2019. On 25 July 2019, cVDPV1 was isolated from a third AFP case from the same state, with date of onset of paralysis on 23 May 2019. Subsequently, on 19 August 2019, a fourth case of VDPV1 has been confirmed in a six-year-old child, with onset of paralysis on 23 July 2019. The child has no history of vaccination with OPV. In addition, the virus has also been isolated from seven healthy community contacts. These linked viruses have 25 to 31 nucleotide changes from Sabin 1. All cases and contacts are from Hpapun township of Kayin state, Myanmar.

Myanmar’s routine immunization coverage is estimated at 91% for three doses of bivalent oral polio vaccine (bOPV) in 2018. Neighbouring countries including Thailand and other countries in South East Asia have been informed of the confirmed cVDPV1, and subnational surveillance is being strengthened across the region. In 2018, Myanmar and Kayin state met certification standards for AFP surveillance with non-polio AFP rate of 3.45, and stool adequacy rate of 100% for Kayin state.

The summaries below provide a situational update on circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreaks in the WHO African and Eastern Mediterranean regions. No wild poliovirus has been detected on the African continent since September 2016.

In the Lake Chad Basin (LCB) sub-region, multiple cVDPV2 outbreaks continue to spread. All the countries that comprise the sub-region (Niger, Cameroon, and Nigeria) have reported outbreaks in either human or environmental samples.

The summaries below provide a situational update on circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreaks in the WHO African and Eastern Mediterranean regions. No wild poliovirus has been detected on the African continent since September 2016.

In the Lake Chad Basin (LCB) sub-region, multiple cVDPV2 outbreaks continue to spread. All the countries that comprise the sub-region (Niger, Cameroon, and Nigeria) have reported outbreaks in either human or environmental samples.