Rapid Risk Assessment: Outbreak of circulating vaccine-derived poliovirus type 1 in Ukraine, 4 September 2015

Risk assessment

European Centre for Disease Prevention and Control. Outbreak of vaccine-derived poliovirus type 1 (cVDPV1) in Ukraine, August 2015 – 2 September, Stockholm, 2015.

​This risk assessment was triggered by two cases of paralytic poliomyelitis in children, caused by circulating vaccine-derived poliovirus type 1 (cVDPV1) in Ukraine during June and July 2015. The outbreak of poliomyelitis in Ukraine is not unexpected, given the low polio vaccination uptake and coverage. It represents a threat to public health in Ukraine and the EU/EEA Member States and there is an urgent need to assess the risk of further spread within Ukraine and international spread from Ukraine.

Executive summary

​Two cases of paralytic poliomyelitis caused by circulating vaccine-derived poliovirus type 1 (cVDPV1) were confirmed in Ukraine on 28 August 2015. The genetic similarity between the isolates indicates active transmission of cVDPV1. Both cases are from the Zakarpatskaya oblast [region], in south-western Ukraine, bordering Romania, Hungary, Slovakia and Poland.

There is a risk that cVDPV will be imported and transmitted in the EU via a recently infected person shedding the virus and this is assessed in a new ECDC rapid risk assessment. The highest risk of importation and onward transmission is likely to exist in the border areas with Ukraine, particularly in areas where under-vaccinated populations are concentrated on both sides of the border and where there is a high volume of border crossings in both directions.

However, the risk that importation of cVDPV from Ukraine to the EU/EEA would result in a case of paralytic poliomyelitis is low, given the high polio vaccination uptake in EU/EEA Member States.
Member States are also encouraged to review the options proposed by ECDC in the 2013 rapid risk assessment Wild polio virus 1 transmission in Israel – what is the risk to the EU/EEA. Public health authorities, travel medicine clinics and other healthcare providers should advise EU residents who plan to visit Ukraine of the need to be up-to-date with their polio vaccinations.