Bamako, 7 September 2015 – A case of circulating vaccine-derived poliovirus type 2 (cVDPV2) has been confirmed in Bamako, the capital and largest city of Mali. The country is on high alert after national authorities detected a paralysis case with onset 20 July 2015. The patient is a 19-month old child of Guinean nationality whose paralysis occurred 7 days prior to the child’s arrival in Bamako to seek health care. The last case of wild polio virus (WPV) in Mali dates back to June 2011 in Goundam, Timbuktu Region.
The current detected virus is genetically linked to a confirmed VDPV detected in Siguiri district, in the Kankan Region of Guinea in August 2014, and has been circulating across international borders for more than 2 years without detection.
The risk of spread of this virus is deemed high and it has the capacity to cause paralytic disease in humans or kill. The emergence and circulation of VDPV2 reveals low population immunity against the virus due to low rates of vaccination coverage in Guinea. Consequently, oral polio vaccine (OPV) must be administered multiple times to stop the outbreak and protect children.
The Ministries of Health in both countries (Mali and Guinea), WHO and the other partners are currently conducting investigations to determine the circumstances behind the emergence and spread of this virus. At the same time, emergency operations to mount a robust and appropriate response are being organized in both countries to stop the spread of the virus and speedily put an end to the outbreak.
“As soon as the new virus was identified, immediate actions were taken to initiate appropriate and targeted immunization activities that are in line with the recent Global Polio Eradication Initiative (GPEI) guidelines,” says Dr Lucien Manga, acting WHO Representative in Mali.
“The Government of Guinea and partners are informed and we have started evaluating all available resources to prepare for the campaign,” says Dr Mamoudou Harouna Djingarey, Deputy WHO Representative in Guinea.
The emergency response must include at least 3 high quality polio campaigns to stop any further spread to other communities. It is highly important for communities to ensure that all under-five children are vaccinated during the 3 rounds of polio campaigns. The first round of immunization will start this week in Mali and within 14 days in Guinea, according to the guidelines.
Experience from other countries indicates that mass vaccination campaigns need to be carefully planned, prepared and implemented with adequate supportive supervision to guarantee their utmost efficiency. In addition, routine immunization systems should be quickly strengthened in both countries to sustain population immunity and avoid the occurrence of poliovirus (wild or cVDPVs) outbreaks.
Polio is a highly contagious, devastating disease that mainly affects young children in areas with poor sanitation. The virus enters the body through the mouth and spreads easily via faecal contaminated food and water. It invades the nervous system and can cause permanent paralysis or death. Initial symptoms include fever, fatigue, headache, vomiting, stiffness in the neck and pain in the limbs.
WHO will continue to support the Ministries of Health of Mali and Guinea to enhance epidemiological surveillance of the virus in order to ensure the timely detection of any outbreaks. It will specifically carry out all necessary actions, including high quality mop-up responses to interrupt all poliovirus transmission.