Polio this week as of 28 February 2018

• New on http://polioeradication.org/: Reaching all children in the Lake Chad basin.

• 23 February marked 64 years since the first large-scale trial of inactivated polio vaccine (IPV). Developed by Joseph Salk, IPV was found to be safe and effective, and is now part of routine vaccination programmes worldwide. Each year, it confers lifelong protection against polio to millions of young children.

• Learn more about IPV by watching our brand new animation on the two polio vaccines, available in English, French, and Arabic.

• Summary of newly-reported viruses this week: Afghanistan: Three new wild poliovirus type 1 (WPV1) positive environmental samples have been reported in Nangarhar province. Pakistan: Four new WPV1 positive environmental samples have been reported, two collected in Sindh province, one in Khyber Pakhtunkhwa province, and one in Balochistan province.

• See country-specific sections for further details.

Weekly country updates as of 28 February 2018

Afghanistan

• No new cases of wild poliovirus type 1 (WPV1) were reported in the past week.

• The total number of officially reported WPV1 cases in Afghanistan in 2018 remains three.

• The most recent case (by date of onset) was reported in Spinboldak district, Kandahar province, with onset on 6 January 2018.

• Three new WPV1 positive environmental samples were reported this week in Nangarhar province. Two samples were collected from Jalalabad district, both on 27 January, and one was collected from Behsud district, on 28 January.

• The next set of supplementary immunization days are planned for 12 March, during which vaccinators will aim to vaccinate children across 34 provinces using bivalent oral polio vaccine (bOPV). The days are synchronised with a campaign that will take place in Pakistan, part of efforts to interrupt transmission of the virus across the shared border.

• Read the latest polio update from Afghanistan to see information on cases, surveillance and vaccination campaigns.

Pakistan

• No new cases of wild poliovirus type 1 (WPV1) were reported in the past week.

• The total number of officially reported WPV1 cases in Pakistan in 2017 remains eight. There are no cases reported in 2018.

• The most recent case (by date of onset) was reported in Zhob district, Balochistan province, with onset on 15 November 2017.

• Four new WPV1 positive environmental samples were reported this week. Two were collected in Sindh province, one in Hyderabad district on 9 February, and one in Jacobabad district on 12 February. One was collected in Khyber Pakhtunkhwa province, Peshawar district, on 10 February, and one was collected in Balochistan province, Quetta district, on 13 February.

• The next set of supplementary immunization days are planned for 12 March, during which vaccinators will aim to vaccinate children across eight provinces using bivalent oral polio vaccine (bOPV). The days are synchronised with a campaign that will take place in Afghanistan, part of efforts to interrupt transmission of the virus across the shared border.

• Read the latest polio update from Pakistan to see information on cases, surveillance and vaccination campaigns.

Nigeria

• No new cases of wild poliovirus type 1 (WPV1) were reported in the past week.

• The total number of WPV1 cases for 2016 is four and no cases have been reported in 2017 or 2018.

• The most recent case (by date of onset) was reported in Monguno Local Government Area, Borno, with onset on 21 August 2016.

• Nigeria continues to implement an emergency response to the detected WPV1 strain and circulating vaccine-derived poliovirus type 2 (cVDPV2) strains affecting the country (last detected in 2016).

• The next immunization days are planned for early March, synchronized with campaigns in countries across the Lake Chad basin.

• As part of the emergency response, subnational surveillance continues to be strengthened

Lake Chad Basin

• The detection of wild poliovirus type 1 (WPV1) (Borno state, Nigeria in 2016) and circulating vaccine-derived poliovirus type 2 (cVDPV2) (Borno and Sokoto states in 2016) continue to pose a risk to the neighbouring countries of the Lake Chad basin.

• Emergency outbreak response efforts continue across the Lake Chad basin, together with activities to fill subnational surveillance gaps across the region.

• These activities include efforts to vaccinate children at markets, in internally displaced persons camps, and at international borders.

• The next set of supplementary immunization days are planned for early March, synchronized across all countries in the Lake Chad basin.

• Read the latest polio update from the Lake Chad basin to see information on surveillance and vaccination campaigns.

Central Africa

• No new cases of circulating vaccine-derived poliovirus type 2 (cVDPV2) were reported this week in the Democratic Republic of the Congo. The total number of officially reported cVDPV2 cases in the DRC in 2017 remains 21. There are no cases reported in 2018.

• The most recent confirmed case (by date of onset) was reported in Ankoro district, Tanganyika province, with onset on 3 December 2017.

• In response to recent cases, the government of the Democratic Republic of the Congo (DRC) has announced the cVDPV2 outbreak ongoing in the country a Public Health Emergency of National Concern.

• The Ministry of Health, supported by WHO and partners of the Global Polio Eradication Initiative, remains fully committed to outbreak response, including use of monovalent oral polio vaccine type 2 (mOPV2) across the country, in line with internationally-agreed outbreak response protocols.

• Children living in the districts where the latest cases were reported were last targeted with mOPV2 during December vaccination days. The next campaign will take place following the completion of microplanning exercises to ensure high campaign coverage.

• Surveillance and immunization activities continue to be strengthened in neighbouring countries.

• Read the latest polio update from the DRC to see information on surveillance and vaccination campaigns.

• Learn more about vaccine-derived polioviruses through this short animation or this ‘Coffee with Polio Experts’ video.

Horn of Africa

• Circulation of vaccine-derived poliovirus type 2 (cVDPV2) is confirmed in Somalia.

• Three vaccine-derived poliovirus type 2s (VDPV2s) were isolated from two environmental samples collected in Hamarweyn district, Banadir province (Mogadishu), one on 4 January, and one on 11 January 2018. These latest isolates are genetically linked to previously isolated VDPV2s from 2017, collected on 22 October and 2 November from environmental samples collected from Waberi district, Banadir province. In total, four environmental samples (with seven unique virus sequences) positive for cVDPV2 have been collected in Somalia between October 2017, and January 2018.

• No cases of acute flaccid paralysis (AFP) associated with this cVDPV2 have been detected at this time – the viruses were all isolated from environmental samples.

• Surveillance for AFP cases in the area is being strengthened.

• Since detection of the initial isolates in 2017, outbreak response campaigns in line with internationally-agreed guidelines have been implemented, consisting of two large-scale immunization activities (SIAs) in Banadir, Lower Shabelle and Middle Shabelle provinces. A third SIA is planned for March 2018, and further response based on evolving epidemiology and ongoing risk assessment is being evaluated.

• WHO and its partners are continuing to support local public health authorities in conducting field investigations and risk assessments to more clearly assess any potential risk of circulation of the identified cVDPV2, and to continue to support the outbreak response and strengthening of disease surveillance.

• Read our Somalia country page to see information on surveillance and vaccination campaigns.

• Learn more about vaccine-derived polioviruses through this short animation or this ‘Coffee with Polio Experts’ video.

The Middle East

• No new cases of circulating vaccine derived poliovirus type 2 (cVDPV2) were reported this week.

• The total number of officially reported cVDPV2 cases in Syria in 2017 remains 74. There are no cases reported in 2018.

• The most recent case (by date of onset) was reported in Boukamal district, with onset on 21 September 2017.

• An inactivated polio vaccine (IPV) immunization round continues in accessible areas of Aleppo utilizing mobile and fixed teams. To date the round has reached a total of 233 518 children aged 2-23 months, representing 71% of the estimated target, in Damascus, Hasakah, parts of Aleppo governorates, and Jurmana district of rural Damascus.

• All empty vials of monovalent Oral Polio Vaccine type 2 (mOPV2) have been collected and destroyed in Damascus.

• Preparations are ongoing for a nationwide immunization round utilizing bivalent OPV (bOPV), which is planned for March. The campaign will target all children aged less than 5 years.

• An independent external surveillance review has concluded in Iraq. The Ministry of Health Iraq has accepted a key recommendation to revitalize the AFP surveillance system in conflict affected northern governorates bordering Syria.

• Read the latest polio update from Syria to see information on cases, surveillance and vaccination campaigns.

• Learn more about vaccine-derived polioviruses through this short animation or this ‘Coffee with Polio Experts’ video.