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Polio this week as of 25 May 2016

     

  • This week, health ministers from around the world are convening in Geneva for the annual World Health Assembly (WHA). Among other public health topics, delegates will review and discuss the latest global polio epidemiology. The GPEI has set up a WHA-specific polio website, with the key documents that are guiding discussions.
  • At the Women Deliver conference in Copenhagen focussing on solutions to the health, economic and social challenges facing girls and women, the Government of Canada announced a Can$19.9 million contribution to Nigeria’s polio eradication efforts.
  • From 17 April to 1 May, 155 countries and territories participated in the historic trivalent to bivalent oral polio vaccine switch, withdrawing the type two component of the vaccine to protect future generations against circulating vaccine-derived polioviruses. Track the switch live.



 

The Trivalent to Bivalent Oral Polio Vaccine Switch



  • Between 17 April and 1 May, the type 2 component of the oral polio vaccine (OPV) is being removed from use through aglobally synchronized switch from the trivalent to bivalent oral polio vaccine. This is the first stage of objective 2 of the Polio Eradication and Endgame Strategic Plan 2013-2018 to withdraw OPV in a phased manner starting with the type 2 component following the eradication of wild poliovirus type 2 in September 2015.

  • Follow a live update of which countries have undergone the switch. Learn more about why the switch is such an important part of ensuring a polio-free world through this series of videos.
  • The following indicators are being carefully tracked to ensure the switch goes smoothly. As of 24 May:

    • 155 of 155 (100%) countries and territories have stopped using the trivalent oral polio vaccine.

    • Independent monitoring to ensure the switch goes smoothly has begun in 152 countries (100%).

    • The National Validation Committee has received switch monitoring data in 145 countries (95%).

    • The WHO Regional Offices has received the National Validation Report from 147 countries (95%). 

     

 
  

Wild poliovirus type 1 and Circulating vaccine-derived poliovirus cases



Total cases

Year-to-date 2016

Year-to-date 2015

Total in 2015

WPV

 cVDPV

 WPV

 cVDPV

 WPV

 cVDPV

Globally

16

3

25

2

74

32

- in endemic countries

16

0

25

2

74

 3

- in non-endemic countries

0

3

0

0

0

 29

 

 

Case breakdown by country



Countries

Year-to-date 2016

Year-to-date 2015

Total in 2015

Onset of paralysis of  most  recent case

WPV

cVDPV 

WPV 

cVDPV

 WPV

cVDPV 

 WPV

 cVDPV

Afghanistan 5 0 2 0 20 0 04-Apr-16 NA
Pakistan  11 0 23 2 54 2 26-Apr-16 09-Feb-15
Guinea 0 0 0 0 0 7 NA 14-Dect-15
Lao PDR  0 3 0 0 0 8 NA 11-Jan-16
Madagascar 0 0 0 0 0 10 NA 22-Aug-15
Myanmar 0 0 0 0 0 2 NA 05-Oct-15
Nigeria 0 0 0 0 0 1 NA 16-May-15
Ukraine 0 0 0 0 0 2 NA 07-Jul-15



NA: onset of paralysis in most recent case is prior to 2015. Figures exclude non-AFP sources. Madagascar, Ukraine and Lao PDR cVDPV1, all others cVDPV2. cVDPV definition: see document "Reporting and classification of vaccine-derived polioviruses" at http://www.polioeradication.org/Portals/0/Document/Resources/VDPV_ReportingClassification.pdf. Implementation as of 15 August 2015.



Afghanistan

         
  • No new cases of wild poliovirus type 1 (WPV1) were reported in the past week. The total number of WPV1 cases for 2016 remains five.
  • No WPV1 environmental positive samples have been reported in 2016. The most recent environmental positive samples were collected on 27 December 2015 - one in Jalalabad in Nangarhar province and the second in the city of Kabul.
  • Subnational Immunization Days (SNIDs) will take place in high risk areas on 1 – 7 June using the inactivated polio vaccine (IPV) and the bivalent oral polio vaccine (bOPV). Further SNIDs will take place on 18 – 22 July using bOPV. The next National Immunization Days (NIDs) will take place on 15 – 19 August.

Pakistan

               
  • One new case of wild poliovirus type 1 (WPV1) was reported in the past week, from Bannu district in Khyber Pakhtunkhwa (KP) province with onset of paralysis on 26 April. It is the most recent case in the country, and brings the total number of WPV1 cases for 2016 to 11, compared to 23 at this date in 2015.
  • Four new WPV1 environmental positive samples were reported in the past week: two collected from Sindh province in the districts of Khi Gulshan-Iqbal and Jacobabad on 15 and 10 March respectively, one in the Rawalpindi district of Punjab on 14 April, and the most recent in Peshawar district of Khyber Pakhtunkhwa on 22 April. Although four positives were reported this week, two duplicates were removed, thus the total went from 17 to 19 environmental positives.
  • Efforts continue to further strengthen surveillance activities in all provinces of the country.

Lao People's Democratic Republic

             
  • No new cases of circulating vaccine-derived poliovirus type 1 (cVDPV1) were reported in the past week. The most recent case was reported in Fuang district of Vientiane province, with onset of paralysis on 11 January 2016. The total number of cVDPV1 cases in 2016 remains three and eight in 2015.
  • Outbreaks of cVDPVs can arise in areas with low population immunity, emphasizing the importance of maintaining strong vaccination coverage.

Madagascar

  • No cases of circulating vaccine-derived poliovirus type 1 (cVDPV1) have been reported in 2016. The most recent case had onset of paralysis on 22 August 2015 from Sud-Ouest region. The total number of cVDPV1 cases for 2015 remains 10.
  • The 2015 cases are genetically linked to the case with onset of paralysis in September 2014, indicating prolonged and widespread circulation of the virus. Learn more about vaccine derived polioviruses here.
  • The third Outbreak Response Assessment in Madagascar found that the surveillance system is not yet strong enough to conclude that polio transmission has been interrupted. Thirty-nine high-risk districts have been identified to receive focused attention.           

    Myanmar

    • No cases of circulating vaccine-derived poliovirus type 2 (cVDPV2) have been reported in 2016. The most recent case was isolated from a 16-month old child in Maungdaw, Rakhine, with onset of paralysis on 05 October. The total number of cVDPV2 cases in 2015 remains two.

    Nigeria

    • No wild poliovirus type 1 (WPV1) cases have been reported in 2016. No cases were reported in 2015. The most recent case had onset of paralysis on 24 July 2014 in Sumaila Local Government Area (LGA), southern Kano state.
    • No new environmental samples of type 2 circulating vaccine-derived poliovirus (cVDPV2) were reported this week. The most recent positive sample was collected in Maiduguri district of Borno state on 23 March 2016.
    • Genetic sequencing of that isolated strain indicates it is most closely linked genetically to a cVDPV2 strain from Borno in November 2013 and last detected in May 2014, indicating the strain has been circulating without detection for almost two years. A detailed field investigation is underway to strengthen active case searching for actual cases of acute flaccid paralysis and to increase the frequency of collection of environmental samples to ascertain the extent of circulation of this strain.
    • A second campaign using monovalent oral polio vaccine type 2 will take place in the north east of Nigeria on 13 – 18 June. The Director General of the World Health Organization has authorized the vaccine release from the global stock pile.

         

    West Africa

    • No circulating vaccine-derived poliovirus type 2 (cVDPV2) cases have been reported from Guinea in 2016. The most recent case was reported from Kankan district, with onset of paralysis on 14 December. The total number of cVDPV2 cases for 2015 remains seven. The 2015 cases are genetically linked to the case with onset in August 2014.
    • National Immunization Days (NIDs) are planned in August in Côte d'Ivoire, Guinea and Sierra Leone and Subnational Immunization Days (SNIDs) in Niger in September with dates to be confirmed. In October, NIDs are planned in Benin, Guinea, Liberia, Mali and Sierra Leone, and SNIDs in Mauritania.