This Week

Polio this week as of 17 July 2019.

  • In Central African Republic, a series of previously-detected/reported VDPV2s have now been officially classified as ‘circulating’.  Since initial detection of the viruses in May, the country had already operationally considered these viruses to represent an outbreak and implemented emergency outbreak response and declared the event to be a national public health emergency.
  • A cVDPV2 originating in Jigawa, Nigeria, continues to spread.  Genetically-linked virus has been confirmed from an environmental sample in Ghana.
  • In Myanmar, a cVDPV1 has been reported and response measures are being implemented.  Neighbouring countries have been informed of the confirmed cVDPV1, and surveillance for polioviruses is being strengthened across the region.  Myanmar had previously successfully stopped a cVDPV2 outbreak in 2015.
  • Summary of new viruses this week: Afghanistan — one wild poliovirus type 1 (WPV1) case and one WPV1-positive environmental sample; Pakistan— four WPV1 cases and three WPV1-positive environmental samples; Nigeria —three circulating vaccine-derived poliovirus type 2 (cVDPV2) cases, two cVDPV2-positive environmental samples, and one cVDPV2 isolated from a healthy contact; Democratic Republic of Congo (DRC) — five cVDPV2 cases; Central African Republic (CAR) — three cVDPV2 cases, one case classified cVDPV2 based on a positive contact, and ten cVDPV2 community/close contacts ; Angola — one cVDPV2 isolated from healthy child; Ghana — one cVDPV2-positive environmental sample linked to Jigawa/Nigeria outbreak; Myanmar — two cVDPV1 cases and two cVDPV1 positive contacts.

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 17 July 2019

  • One wild poliovirus type 1 (WPV1) case has been reported in the past week in Musaqalah district, Hilmand province. The onset of paralysis was on 5 June 2019. There are 11 WPV1 cases reported in 2019 from Afghanistan. The total number of WPV1 cases for 2018 remains 21.
  • One WPV1-positive environmental sample was reported in the past week from Kandahar district, Kandahar province. The sample was collected on 24 June 2019.
  • Read the latest polio update from Afghanistan to see information on cases, surveillance and vaccination campaigns. 
  • Four wild poliovirus type 1 (WPV1) cases have been reported in the past week: One each from Jehlum and Lahore districts, Punjab province, with onset of paralysis on 21 and 22 June 2019; one each from Bannu and Lakkimarwat districts, Khyber Pakhtunkhwa province, with onset of paralysis on 22 June and 01 July 2019. The total number of WPV1 cases are 45.
  • Three WPV1-positive environmental samples were reported in the past week: one each from Quetta district in Balochistan province; Karachi district in Sindh province; Bannu district in Khyber Pakhtunkhwa province. The samples were collected between 20-27 June 2019.
  • Read the latest polio update from Pakistan to see information on cases, surveillance and vaccination campaigns.

Nigeria

  • Three cases of circulating vaccine-derived poliovirus type 2 have been reported in the past week: one each from Wurno LGA, Sokoto State, Irewole LGA, Osun State and Baruten LGA, Kwara State. The onset of paralysis was on 20 May, 9 June and 14 June 2019 respectively. There are 12 cVDPV2 cases reported in 2019 so far. The total number of cVDPV2 cases in 2018 remains 34.
  • Two positive environmental samples were reported in the past week: Sokoto North LGA, Sokoto State and Ilorin West LGA, Kwara State. The samples were collected on 10 and 13 June 2019 respectively.
  • One cVDPV2 was isolated from a healthy child from Wurno LGA, Sokoto State. The sample was collected on 20 June 2019.
  • Recent confirmation of spread of one of the cVDPV2 outbreaks, 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 mOPV2 response.
  • Read our Nigeria country page to see information on surveillance and vaccination campaigns.

Lake Chad

  • No case of circulating vaccine-derived poliovirus type 2 (cVDPV2) has been 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.

West Africa

  • In Ghana, a cVDPV2-positive environmental sample was reported in the past week in Tamale district, Northern province. The sample was collected on 11 June 2019.
  • Genetic sequencing has confirmed it is linked to the cVDPV2 originating from Jigawa, Nigeria.
  • Across the GPEI partnership, the outbreak preparedness and response task team (OPRTT) is working with our regional and country colleagues in supporting local public health authorities in carrying out a full field investigation and determining if there is a risk of local spread of this virus which might require a response.
  • Surveillance is also being strengthened in neighbouring Togo, Benin, Côte d’Ivoire and Burkina Faso.

Democratic Republic of the Congo (DR Congo)

  • Five cases of circulating vaccine-derived poliovirus type 2 (cVDPV2) have been reported this week in the Democratic Republic of the Congo (DR Congo): three from Malemba-Nkulu district, Haut Lomami province; one each from Tshumbe and Wembo-Nyama districts, Sankuru province. The onset of paralysis was on 10 February, 30 May, 26 May, 23 May, 3 June 2019 respectively.  There are 11 reported cases of cVDPV2 in 2019. The total number of cVDPV2 cases reported in 2018 is 20.  DRC is currently affected by seven separate cVDPV2 outbreaks; one each originated in Haut Katanga, Mongala, Sankuru and two in  Haut Lomami and Kasai provinces.
  • 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

  • No case of circulating vaccine-derived poliovirus type 2 (cVDPV2) has been reported this week in Angola. Total three cVDPV2 cases from two outbreaks are reported in Angola in 2019.
  • A cVDPV2 case was isolated from a healthy child in Kuvango district, Huila province. The sample was collected on 10 June 2019.
  • Read our Angola country page for more information.

Central African Republic

  • A series of previously-detected/reported VDPV2s have now been officially classified as ‘circulating’.
  • Four cVDPV2 cases have now been officially reported from two distinct outbreaks.  Additionally, the country had also already reported genetically-distinct VDPV2s, and had therefore considered these emergencies as an outbreak, even prior to the official classification this week as ‘circulating’.
  • In response, the Government had declared these events to be a national public health emergency and begun implementation of outbreak response.
  • Read our Central African Republic country page for more information.

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) There are six reported cases of cVDPV2 in 2019. The total number of cVDPV2 cases reported in 2018 is 20.  DRC is currently affected by six separate cVDPV2 outbreaks, in the provinces of Haut Katanga; Mongala; Haut Lomami/Tanganika/Haut Katanga/Ituri, Sankuru and Kasai (2).
  • 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:  

  • One case of circulating vaccine-derived poliovirus type 2 (cVDPV2) has been reported this week in Angola in Kuvango district, Huila province, on 30 May 2019.
  • This is the second cVDPV2 outbreak in Angola this year; the earlier outbreak was detected in Lunda Norte province, for which an outbreak response is in progress (in close coordination with DRC).
  • 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.
  • Read our Angola country page for more information.
  • 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) outbreak 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 in neighbouring Papua New Guinea.
  • Learn more about Indonesia polio outbreak response through weekly situational report http://www.searo.who.int/indonesia/topics/immunization/poliositrepindonesia9english.pdf?ua=1
  • 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.
  • No cVDPV2 cases were reported in the past week.  The total number of cVDPV2 cases in the country remains one.
  • China continues to maintain strong routine immunization coverage both with IPV and bivalent OPV reaching more than 95% nationwide, and strong poliovirus surveillance including through environmental surveillance.
  • The Government of China is reacting rapidly and efficiently to confirmation of the cVDPV2, by conducting a full field and epi-investigation, strengthening disease surveillance, investigating the origin of the virus and planning an appropriate outbreak response.
  • China had successfully responded to a WPV1 outbreak in 2011, stopping an outbreak (due to an importation from Pakistan) in record time.
  • Learn more about vaccine-derived polioviruses through this short animation or this ‘Coffee with Polio Experts’ video.
  • Two circulating vaccine-derived poliovirus type 1 (cVDPV1) have been reported this week from Papun district, Kayin province. The onset of paralysis was on 22 May and 14 June 2019.
  • Two cVDPV1 viruses were isolated from contacts in Papun district, Kayin province. Both the samples were collected on 18 June 2019.
  • Myanmar’s routine immunization coverage is strong, estimated at 89% at national level for bivalent OPV.  Neighbouring countries have been informed of the confirmed cVDPV1, and subnational surveillance is being strengthened across the region.
  • 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 viruses; active surveillance is being strengthened; subnational population immunity levels are being analyzed; and, outbreak response is being planned.