Status: affected by circulating vaccine-derived poliovirus

Circulation of vaccine-derived poliovirus type 2 (cVDPV2) has been confirmed in Niger, related to a cVDPV2 affecting Jigawa, Nigeria. Surveillance for AFP cases is being strengthened and an outbreak response will be implemented.

The detection of cVDPVs underscores the importance of maintaining high levels of routine vaccination coverage at all levels to minimize the risk and consequences of any poliovirus circulation. A robust outbreak response is needed to rapidly stop the VDPV2 transmission. WHO will continue to evaluate the epidemiological situation and outbreak response measures being implemented.

Polio this week in Lake Chad Basin

  • No case of circulating vaccine-derived poliovirus type 2 (cVDPV2) has been reported in the past week. The most recent cVDPV2 isolated in the country was in Magaria district, Zinder province with an onset of paralysis on 5 December 2018.
  • The total number of cVDPV2 cases in 2018 reported in Niger in 2018 is ten.  The outbreak is genetically-linked to the cVDPV2 outbreak originating in Jigawa, Nigeria. Virus was isolated from children with acute flaccid paralysis (AFP) from Zinder region, located in the south of Niger and on the border with Nigeria, with dates of onset of paralysis ranging from 18 July through 5 December 2018.
  • Acute flaccid paralysis surveillance and routine immunization across the country with focus on the infected provinces and the provinces at the international borders with Nigeria are being reinforced.
  • Active case finding for additional AFP cases is continuing, and additional surveillance measures such as increasing the frequency and extent of environmental surveillance and community sampling of healthy individuals is being expanded.

International Health Regulations

Countries affected by poliovirus transmission are subject to International Health Regulations Temporary Recommendations that request them to declare a case of polio as a national public health emergency and consideration vaccination of all international travellers, as per temporary recommendations issued as of February 2019.

Travel advice

WHO’s International Travel and Health recommends that all travellers to polio-affected areas be fully vaccinated against polio. Residents (and visitors for more than 4 weeks) from infected areas should receive an additional dose of OPV or inactivated polio vaccine (IPV) within 4 weeks to 12 months of travel.

More on vaccine-derived polioviruses