This Week

Polio this week as of 19 June 2019

  • In Angola, a circulating vaccine-derived poliovirus type 2 (cVDPV2) has been confirmed.  See ‘Central Africa’ section below for more information.
  • In the Horn of Africa, a cVDPV2 case has been detected in Somali province, Ethiopia, linked to the ongoing cVDPV2 outbreak affecting the region (notably Somalia).  Since detection of the cVDPVs in the Horn of Africa in 2018, Ethiopia had declared these outbreaks – together with the Ministries of Health of Kenya and Somalia – to be a regional public health emergency and has been participating in regional outbreak response. See ‘Horn of Africa’ section below for more.
  • In Papua New Guinea, more than one million children are to be vaccinated against measles-rubella and polio.  More.  To mark the launch of the campaign, the Honorable Prime Minister James Marape personally administered polio vaccine at a launch ceremony.  More.
  • Summary of new viruses this week: Pakistan – two WPV1 cases and one WPV1-positive environmental sample; Nigeria – five circulating vaccine-derived poliovirus type 2 (cVDPV2) positive environmental samples; Ethiopia – one cVDPV2 case; Somalia – one cVDPV2 isolated from a healthy community contact; and, Iran – one WPV1-positive environmental sample.  See country sections below for more details.

NA: Onset of paralysis in most recent case is prior to 2017. Figures exclude non-AFP sources. In 2018, cVDPV includes all three serotypes 1, 2 and 3.
For Somalia: 1 cVDPV2 and cVDPV3 isolated from one AFP case.
cVDPV definition: see document “Reporting and classification of vaccine-derived polioviruses” at [pdf].

Weekly country updates as of 19 June 2019

  • No wild poliovirus type 1 (WPV1) cases were reported in the past week.  The total number of WPV1 cases for 2019 remains eight.
  • Read the latest polio update from Afghanistan to see information on cases, surveillance and vaccination campaigns.
  • Two wild poliovirus type 1 (WPV1) cases were reported in the past week, from Khyber Pakhtunkhwa (KP) province, one from Shangla district and the other one from Bannu district.  The onset dates of paralysis are 18 and 22 May respectively, bringing the total number of WPV1 cases in 2019 to 24.
  • Additionally, one WPV1-positive environmental sample was reported in the past week, collected on 20 May from Quetta, Balochistan.
  • Read the latest polio update from Pakistan to see information on cases, surveillance and vaccination campaigns.
  • Five circulating vaccine-derived poliovirus type 2 (cVDPV2) viruses were reported in the past week from environmental samples, collected in May from Kwara and Lagos states.  The total number of cVDPV2 cases reported in 2019 remains eight.
  • Recent confirmation of spread of the cVDPV2 outbreak, both within Nigeria and internationally, underscores the urgent need to fill remaining vaccination gaps in the ongoing outbreak response, and to optimize the geographic extent and operational quality of monovalent OPV type 2 (mOPV2) response.
  • Read our Nigeria country page to see information on surveillance and vaccination campaigns.
  • No circulating vaccine-derived poliovirus type 2 (cVDPV2) was reported in the past week.
  • In the Lake Chad region, cVDPV2 linked to the outbreak originating in Nigeria has been detected in Niger (one case in 2019 and ten cases in 2018), and Cameroon (one positive environmental sample, collected on 20 April 2019 in Extreme Nord
  • The risk of further cVDPV2 spread across the Lake Chad subregion remains high.

Democratic Republic of Congo (DR Congo):

  • No case of circulating vaccine-derived poliovirus type 2 (cVDPV2) has been reported this week in the Democratic Republic of the Congo (DR Congo).  So far, one cVDPV case has been reported in DRC in 2019.  The total number of cVDPV2 cases reported in 2018 is 20.  DRC is affected by four separate cVDPV2 outbreaks, in the provinces of Haut Katanga; Mongala; Haut Lomami/Tanganika/Haut Katanga/Ituri and Kasai.
  • Read our Democratic Republic of the Congo 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.

Angola:  

  • A circulating vaccine-derived poliovirus type 2 (cVDPV2) has been confirmed in Angola.  The virus was isolated from an acute flaccid paralysis (AFP) case, with onset of paralysis on 05 April 2019, from Lunda Norte province, bordering the Democratic Republic of Congo (DR Congo).  DR Congo has been affected by known circulating VDPV2 (cVDPV2) outbreaks since early 2017 and has been conducting outbreak response with monovalent OPV type 2 (mOPV2).
  • The Ministry of Health and local health authorities are undertaking a detailed investigation and the partners of the Global Polio Eradication Initiative (GPEI) are providing support as required.  A full epidemiological and virological field investigation is ongoing, including to ascertain the source and origin of the isolated virus; active surveillance is being strengthened; subnational population immunity levels are being analysed; and, outbreak response is being planned.
  • Given cross-border population movements, subnational immunity and surveillance gaps, Lunda Norte province is considered at high-risk for further transmission of the isolated cVDPV2.  It is critical that an emergency, preventive outbreak response now be fully implemented in the province. In absence of a timely and high-quality vaccination response, there is imminent risk of further transmission of this cVDPV2, potentially leading to a significant outbreak of paralytic polio.  Two preventive emergency outbreak response campaigns with mOPV2 are planned in Lunda Norte province, to be synchronized with campaigns in neighbouring areas of DR Congo, to interrupt any potential cross-border circulation.
  • Separately, a second VDPV2 was also isolated from a further AFP case first detected in Huila province, who subsequently travelled thereafter to Huambo province to seek care.  Initial sequencing suggests it is unrelated to the VDPV2 isolated in Lunda Norte (or any other VDPV2 isolated elsewhere).
  • This event further underlines the risk of cVDPV2 across Africa.
  • Read our Angola country page for more information.
  • A circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreak in the Horn of Africa has been detected in Somali province, Ethiopia.  The virus was isolated from an acute flaccid paralysis (AFP) case with onset of paralysis on 20 May 2019.
  • Genetic sequencing confirms that the isolated virus is linked to an ongoing cVDPV2 outbreak detected in the Horn of Africa in 2018, with cases reported in Somalia as well as from an environmental sample in Kenya.  Separately, Somalia is also affected by a circulating vaccine-derived poliovirus type 3 (cVDPV3) outbreak.
  • Somalia has reported a total of 15 cVDPV cases (eight type 2, six type 3 and one coinfection of both type 2 and type 3) since the beginning of the outbreaks.  The most recent cVDPV3 virus was from an AFP case from Runingod district, Middle Shabelle province with an onset date of paralysis on 7 September 2018.  Circulating VDPV2 has also been detected during 2018 in one environmental sample in Kenya collected on 21 March 2018.
  • Since detection of the cVDPVs in the Horn of Africa in 2018, Ethiopia had declared the outbreaks – together with the Ministries of Health of Kenya and Somalia – to be a regional public health emergency and has been participating in regional outbreak response.
  • Given cross-border population movements across the Horn of Africa and subnational immunity and surveillance gaps, Somali province is considered at high-risk of further transmission of this isolated cVDPV2.
  • The Ministry of Health and local health authorities are undertaking a detailed investigation and the partners of the Global Polio Eradication Initiative (GPEI) are providing support as required.  A full epidemiological and virological field investigation is ongoing; active surveillance is being strengthened; subnational population immunity levels are being analysed; and, outbreak response is being planned.
  • This event further underlines the risk of cVDPV2 across the Horn of Africa.
  • Learn more about vaccine-derived polioviruses through this short animation or this ‘Coffee with Polio Experts’ video.
  • No new cases of circulating vaccine-derived poliovirus type 1 (cVDPV1) were reported this week.  The total number of cases in 2018 remains 26.
  • The most recent cVDPV1 virus was isolated from an environmental sample collected in the National Capital district on 6 November 2018.
  • A GPEI Outbreak Response Assessment reviewed the impact of current outbreak response and concluded that overall strong response had been implemented.  Commending national and subnational public health authorities and health workers on their efforts, the Assessment team underscored the need on now filling any residual subnational surveillance and immunity gaps.
  • The team reviewed all aspects of the response, and noted significant efforts and improvements, including on service delivery, surveillance strengthening, data analysis, cold chain/reverse cold chain refurbishment, vaccine acceptance and community engagement, health worker engagement, collaboration with neighbouring Indonesia and outreach to remote areas/communities. In particular, the group noted the strong collaboration between outbreak response and strengthening of routine immunization, including through systematic collaboration with Gavi, the Vaccine Alliance, and highlighted that this model of working should be replicated in other outbreak settings.
  • Read our Papua New Guinea country page to see information on surveillance and vaccination campaigns.
  • No case of circulating vaccine-derived poliovirus type 2 (cVDPV2) has been reported this week.  The total number of cases in 2018 remains one.
  • In addition to the confirmed case, the same virus was also isolated from two healthy community contacts, reported on 10 and 17 December 2018.
  • The GPEI and partners are working with country counterparts to support the local public health authorities in conducting a field investigation (clinical, epidemiological and immunological) and thorough risk assessment to discuss planning and implementation of immunization and outbreak response.
  • Read our Mozambique country page to see information on cases, surveillance and response to the developing outbreak.
  • No circulating vaccine-derived poliovirus type 1 (cVDPV1) cases were reported this week.
  • In total, three genetically-linked circulating vaccine-derived poliovirus type 1 (cVDPV1) isolates were detected from Papua province: a cVDPV1 from an acute flaccid paralysis (AFP) case, with onset of paralysis on 27 November 2018, and two cVDPV1 isolates from healthy community contacts, collected on 24 January and 13 February 2019.  This outbreak is not linked to the cVDPV1 currently affecting neighbouring Papua New Guinea.
  • One wild poliovirus type 1 (WPV1)-positive environmental sample was reported in the past week, from Sistan and Balochistan province, collected on 20 May 2019.
  • In total, three WPV1-positive environmental samples have been reported in 2019, all from Sistan and Balochistan province.  The isolated viruses have been detected in environmental samples only, and genetic sequencing confirms they are linked to WPV1 circulating in Karachi, Pakistan.
  • The Ministry of Health and local health authorities are undertaking a detailed investigation and the partners of the Global Polio Eradication Initiative (GPEI) are on standby to provide support as required.  An immediate risk assessment suggests that this event has limited public health implications, given Iran’s very high levels of routine immunization coverage and strong disease surveillance.  However, this event further underlines the risk of international spread of WPV1 from Pakistan/Afghanistan.