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Statement on the 6th IHR Emergency Committee meeting regarding the international spread of wild poliovirus

WHO statement
17 August 2015

The sixth meeting of the Emergency Committee under the International Health Regulations (2005) (IHR) regarding the international spread of wild poliovirus was convened via teleconference by the Director-General on 4 August 2015. The following IHR States Parties submitted an update on the implementation of the Temporary Recommendations since the Committee last met on 24 April 2015: Afghanistan and Pakistan.

The Committee noted that since the declaration that the international spread of polio constituted a Public Health Emergency of International Concern (PHEIC), strong progress has been made by countries toward interruption of wild poliovirus transmission, implementation of Temporary Recommendations issued by the Director-General, and overall decline in occurrence of international spread of wild poliovirus. The Committee appreciated these commendable achievements.

The Committee acknowledged the strong efforts of countries in Africa to eradicate polio noting that no cases of wild poliovirus have been reported in Africa for nearly twelve months.

The Committee noted that the international spread of wild poliovirus has continued, with two new documented exportations from Afghanistan into Pakistan which occurred in 2015. The poliovirus isolates found in the two cases in Pakistan were more closely related to strains recently circulating in Afghanistan than to those currently found in Pakistan. While one of these cases occurred in Quetta, near the Afghanistan-Pakistan border, the second case was found in a district of Sindh province that does not border Afghanistan, underlining that the risk of distant international spread from zones of poliovirus transmission remains. The committee was concerned that the Temporary Recommendations for international travellers of all ages are not being implemented fully in Afghanistan – particularly at airports. Vaccination of international air travellers is not being tracked, and no exit screening and restriction of unvaccinated travellers has been implemented at international airports. The committee noted that several countries are now requiring proof of polio vaccination from Pakistan and Afghanistan at points of entry, which reinforces the importance of the Temporary Recommendations for travellers being properly implemented. The increasing risk of international spread associated with the ongoing suspension of mass vaccination campaigns in Kandahar province was another major source of concern.

In 2015, Pakistan has reported less than a third of the number of cases that were reported during the same period in 2014. There has been no exportation from Pakistan since October 2014, and the number of persistently missed and inaccessible children is declining in Pakistan. Despite this improvement, however, Pakistan has had 85% of all global wild polio virus cases in 2015. The risk of new exportations from Pakistan remains, with ongoing transmission in the country during the low transmission season, and the commencement of the high transmission season in May.

The Committee noted that while Pakistan and Afghanistan have historically shared a vast common zone of poliovirus transmission, the recent spread between the two countries is occurring from discrete zones of persistent transmission in each country. Strong programmatic action in such zones should interrupt such cross-border transmission, as illustrated by the experience in regions that were previously endemic for polio. The committee also emphasized that under the IHR, spread of poliovirus between two Member States constitutes international spread. While the Committee appreciated that efforts are being made for cross border collaboration, the committee recommended that coordination and quality of cross-border vaccination and surveillance activities should be further strengthened to reduce the risk of this international spread. Both countries must achieve interruption of poliovirus transmission simultaneously in order to prevent such international spread from repeatedly setting back progress in both countries. The Committee congratulated Pakistan for the improvements that have been achieved and encouraged international partners to support Afghanistan and Pakistan in the implementation of the IHR requirements.

While the primary measure to prevent international spread remains interruption of wild poliovirus transmission in infected countries, reducing vulnerability and risk of outbreak in vulnerable regions is critically important. Countries or areas affected by conflict are vulnerable to outbreaks of polio because insecurity and inaccessibility can lead to deterioration of public health and immunization. Those vulnerable include the conflict-affected countries in the Middle East, the Horn of Africa and central Africa, particularly the Lake Chad Region. The hard-earned gains can be quickly lost if there is continued disruption of health systems in settings of complex humanitarian emergencies.

The world has reached the critical end stage for global polio eradication and loss of momentum now could reverse or prevent the world achieving this global goal. The Committee unanimously agreed that the international spread of polio remains a PHEIC and recommended the extension of the Temporary Recommendations, as revised, for a further three months. The Committee considered the following factors in reaching this conclusion:

  • The continued international spread of wild poliovirus in 2015, including during the recent low transmission season in Pakistan and Afghanistan, while recognizing the progress achieved and the decrease in the number of cases.
  • The risk and consequent costs of failure to eradicate globally one of the world’s most serious vaccine preventable diseases.
  • The continued necessity of a coordinated international response to improve immunization and surveillance for wild poliovirus, stop its international spread and reduce the risk of new spread with the onset of the high transmission season in May/June 2015.
  • The serious consequences of further international spread for the increasing number of countries in which immunization systems have been weakened or disrupted by conflict and complex emergencies. Populations in these fragile states are vulnerable to outbreaks of polio. Outbreaks in fragile states are exceedingly difficult to control and threaten the completion of global polio eradication during its end stage.
  • The importance of a regional approach and strong cross-border cooperation, as much international spread of polio occurs over land borders, while recognizing that the risk of distant international spread remains from zones with active poliovirus transmission.

The Committee provided the Director-General with the following advice aimed at reducing the risk of international spread of wild poliovirus, based on the risk stratification as follows:

  • States currently exporting wild poliovirus.
  • States infected with wild poliovirus but not currently exporting.
  • States no longer infected by wild poliovirus, but which remain vulnerable to international spread.

The Committee updated and applied the following criteria to assess the period for detection of no new exportations and the period for detection of no new cases or environmental isolates of wild poliovirus:

States no longer exporting (detection of no new wild poliovirus exportation)

  • Wild Poliovirus Case: 12 months after the onset date of the first case caused by the most recent exportation PLUS one month to account for case detection, investigation, laboratory testing and reporting period, OR when all reported AFP cases with onset within 12 months of the first case caused by the most recent importation have been tested for polio and excluded for WPV1, and environmental samples collected within 12 months of the this first case have also tested negative, whichever is the longer.
  • Environmental isolation of exported wild poliovirus: 12 months after collection of the first positive environmental sample in the country that received the new exportation PLUS one month to account for the laboratory testing and reporting period.

States no longer infected (detection of no new wild poliovirus)

  • Wild Poliovirus Case: 12 months after the onset date of the most recent case PLUS one month to account for case detection, investigation, laboratory testing and reporting period OR when all reported AFP cases with onset within 12 months of last case have been tested for polio and excluded for WPV1, and environmental samples collected within 12 months of the last case have also tested negative, whichever is the longer.
  • Environmental isolation of wild poliovirus (no wild poliovirus case): 12 months after collection of the most recent positive environmental sample PLUS one month to account for the laboratory testing and reporting period

Temporary recommendations

States currently exporting wild poliovirus

Pakistan (last exportation: 21 October, 2014) and Afghanistan (last exportation: 6 June 2015). These states should:

  • Officially declare, if not already done, at the level of head of state or government, that the interruption of poliovirus transmission is a national public health emergency; where such declaration has already been made, this emergency status should be maintained.
  • Ensure that all residents and long-term visitors (i.e. > four weeks) of all ages, receive a dose of oral poliovirus vaccine (OPV) or inactivated poliovirus vaccine (IPV) between four weeks and 12 months prior to international travel.
  • Ensure that those undertaking urgent travel (i.e. within four weeks), who have not received a dose of OPV or IPV in the previous four weeks to 12 months, receive a dose of polio vaccine at least by the time of departure as this will still provide benefit, particularly for frequent travellers.
  • Ensure that such travellers are provided with an International Certificate of Vaccination or Prophylaxis in the form specified in Annex 6 of the IHR to record their polio vaccination and serve as proof of vaccination.
  • Restrict at the point of departure the international travel of any resident lacking documentation of appropriate polio vaccination. These recommendations apply to international travellers from all points of departure, irrespective of the means of conveyance (e.g. road, air, sea).
  • Recognising that the movement of people across the border between Pakistan and Afghanistan continues to facilitate exportation of wild poliovirus, both countries should further intensify cross-border efforts by significantly improving coordination at the national, regional and local levels to substantially increase vaccination coverage of travellers crossing the border and of high risk cross-border populations. Both countries have maintained permanent vaccination teams at the main border crossings for many years. Improved coordination of cross-border efforts should include closer supervision and monitoring of the quality of vaccination at border transit points, as well as tracking of the proportion of travellers that are identified as unvaccinated after they have crossed the border.
  • Maintain these measures until the following criteria have been met: (i) at least six months have passed without new exportations and (ii) there is documentation of full application of high quality eradication activities in all infected and high risk areas; in the absence of such documentation these measures should be maintained until the state meets the above criteria of a ‘state no longer exporting’.
  • Provide to the Director-General a monthly report on the implementation of the Temporary Recommendations on international travel, including the number of residents whose travel was restricted and the number of travellers who were vaccinated and provided appropriate documentation at the point of departure.

States infected with wild poliovirus but not currently exporting

The Committee noted that according to the revised criteria above, Nigeria and Somalia, should there be no further detection of wild poliovirus in the next 1-2 months, will meet the criteria for ‘States no longer infected by wild poliovirus, but which remain vulnerable to international spread.’

Until such a time, however, the Committee reiterated its recommendations that Nigeria (last case: 24 July 2014) and Somalia (last case: 11 August 2014) should:

  • Officially declare, if not already done, at the level of head of state or government, that the interruption of poliovirus transmission is a national public health emergency; where such declaration has already been made, this emergency status should be maintained.
  • Encourage residents and long-term visitors to receive a dose of OPV or IPV four weeks to 12 months prior to international travel; those undertaking urgent travel (i.e. within four weeks) should be encouraged to receive a dose at least by the time of departure.
  • Ensure that travellers who receive such vaccination have access to an appropriate document to record their polio vaccination status.
  • Intensify regional cooperation and cross-border coordination to enhance surveillance for prompt detection of poliovirus and substantially increase vaccination coverage among refugees, travellers and cross-border populations.
  • Maintain these measures until the following criteria have been met: (i) at least six months have passed without the detection of wild poliovirus transmission in the country from any source, and (ii) there is documentation of full application of high quality eradication activities in all infected and high risk areas; in the absence of such documentation these measures should be maintained until the state meets the criteria of a ‘state no longer infected’.
  • At the end of 12 months without evidence of transmission, provide a report to the Director-General on measures taken to implement the Temporary Recommendations.

States no longer infected by wild poliovirus, but which remain vulnerable to international spread

Ethiopia, Syria, Iraq, Israel, Equatorial Guinea and Cameroon meet the criteria for this category of risk and should:

  • Enhance surveillance quality to reduce the risk of undetected wild poliovirus transmission, particularly among high risk mobile and vulnerable populations;
  • intensify efforts to ensure vaccination of mobile and cross-border populations, Internally Displaced Persons, refugees and other vulnerable groups;
  • enhance regional cooperation and cross border coordination to ensure prompt detection of wild poliovirus and vaccination of high risk population groups;
  • maintain these measures with documentation of full application of high quality surveillance and vaccination activities; and
  • at the end of 12 months without evidence of reintroduction of poliovirus, provide a report to the Director General on measures taken to implement the Temporary Recommendations.

These countries should provide a final report as per the table below:


Country Most recent case onset / +ve environmental isolate Final Report due
Ethiopia 5-Jan-14 Feb-16
Syrian Arab Republic 21-Jan-14 Feb-16
Israel 30-Mar-14 Apr-16
Iraq 7-Apr-14 May-16
Equatorial Guinea 3-May-14 Jun-16
Cameroon 9-Jul-14 Aug-16

Additional considerations for all infected countries

The Committee strongly urged global partners in polio eradication to provide optimal support to all infected countries at this critical time in the program, particularly in Afghanistan where implementation of the Temporary Recommendations under the IHR is substantially incomplete. The Committee advised that in view of the evolving situation, particularly with the commencement of the high transmission season, periodic review and assessment of the risk of international spread and measures to mitigate these risks are warranted.

Note on vaccine-derived poliovirus

While not the specific subject of the PHEIC, the committee also noted that stopping the outbreaks of circulating vaccine derived poliovirus is a critical component of the Polio Endgame Strategy. The Committee recommended that more attention should be paid to the on-going type 1 circulating vaccine derived poliovirus in Madagascar and cautioned that polio eradication could not be completed until all poliovirus transmission is interrupted. The Committee also urged international partners to offer additional support to Madagascar to address the challenge of on-going circulating vaccine derived poliovirus.

Based on the advice concerning wild poliovirus, the reports made by Afghanistan and Pakistan and the currently available information, the Director-General accepted the Committee’s assessment and on 10 August 2015 determined that the events relating to wild poliovirus continue to constitute a PHEIC. The Director-General endorsed the Committee’s recommendations for ‘States currently exporting wild polioviruses’, for ‘States infected with wild poliovirus but not currently exporting’ and for ‘States no longer infected by wild poliovirus, but which remain vulnerable to international spread’ and extended them, as revised by the Committee, as Temporary Recommendations under the IHR to reduce the international spread of wild poliovirus, effective 10 August 2015. The Director-General thanked the Committee Members and Advisors for their advice and requested their reassessment of this situation within the next three months.

With regard to the concerns about on-going circulating vaccine-derived poliovirus, the Director-General emphasized the critical importance of interrupting all poliovirus transmission, including outbreaks of vaccine-derived poliovirus for successful completion of polio eradication.

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