WHO Issues Statement on the International Spread of Wild Poliovirus

On May 5, 2014 the director-general, Dr. Margaret Chan, declared the international spread of wild poliovirus in 2014 a Public Health Emergency of International Concern (PHEIC) under the International Health Regulations [IHR 2005], issued Temporary Recommendations to reduce the international spread of wild poliovirus, and requested a reassessment of this situation by the Emergency Committee in three months. The second meeting of the Emergency Committee was held on July 31, 2014.

The affected WHO member states that met the criteria for ‘States currently exporting wild poliovirus’ participated in the informational session of the meeting and were as follows: Cameroon, Equatorial Guinea, Pakistan and the Syrian Arab Republic.

During the informational session the WHO secretariat updated the Committee on wild poliovirus transmission and international spread since May 5, 2014. The above affected WHO member states presented information on the implementation of the temporary recommendations issued on May 5, 2014, including the national declaration of a public health emergency and recommendations for travellers, and recent developments in the intensification of national polio eradication strategies.

Using the criteria applied to the declaration of the PHEIC in May, the Committee considered whether the conditions for a PHEIC still apply. After discussion of the information provided, the Committee advised that the international spread of polio in 2014 continues to constitute an extraordinary event and a public health risk to other States for which a coordinated international response continues to be essential.

Since May 5, 2014, and the onset of the high transmission season for polio, there has been new international spread of wild poliovirus in central Asia (from Pakistan to Afghanistan as recently as June 2014) and a poliovirus originating in Central Africa (Equatorial Guinea) was reported from the Americas. The latter had been detected in a single sewage sample that was collected in Brazil in March 2014 at a site that covered an international airport in the state of Sao Paolo. Equatorial Guinea was consequently confirmed as a ‘State currently exporting wild poliovirus’ and informed of the need to implement the relevant Temporary Recommendations, bringing to four the total number of ‘States currently exporting wild poliovirus’. Two of the ‘States currently exporting wild poliovirus’, Pakistan and Cameroon, have had additional cases and geographic expansion of the infected area within each country since May 5, 2014. The possible consequences of international spread have worsened since the declaration of the PHEIC, as susceptible populations living in polio-free but conflict-torn WHO member states and areas have increased, with further deterioration of their routine immunization services.

The international spread of poliovirus in 2014 continues to threaten the ongoing effort to eradicate globally one of the world’s most serious vaccine preventable diseases. It was the unanimous view of the Committee that the conditions for a Public Health Emergency of International Concern (PHEIC) continue to be met.

All four ‘States currently exporting wild poliovirus’ had initiated implementation of the temporary recommendations issued by the director-general on May 5, 2014, and further intensified national eradication efforts. While recognizing and appreciating these efforts, the Committee noted that the application of the temporary recommendations by affected WHO member states remains incomplete. Additional efforts are required to declare and/or operationalize national emergency procedures, to improve vaccination coverage of international travellers and to ensure eradication strategies are fully implemented to international standards in all infected and high risk areas.

The Committee reiterated that the over-riding priority for all polio-infected states must be to interrupt wild poliovirus transmission within their borders as rapidly as possible through high quality application in all geographic areas of the polio eradication strategies. The Committee reinforced the need for a coordinated regional approach to accelerate interruption of virus transmission in each epidemiologic zone.

The Committee provided the following advce to the director-general for her consideration to reduce the international spread of wild poliovirus.
- States Currently Exporting Wild Poliovirus: Pakistan, Cameroon, Equatorial Guinea and the Syrian Arab Republic continue to meet the criteria for such states and pose the highest risk for further wild poliovirus exportations in 2014. The Temporary Recommendations issued by the director-general on May 5, 2014 for such states should continue to be implemented.
- States Infected with Wild Poliovirus but Not Currently Exporting: Afghanistan, Ethiopia, Iraq, Israel, Nigeria, and Somalia continue to meet the criteria for such states and pose an ongoing risk for new wild poliovirus exportations in 2014. The temporary recommendations issued by the director-general on May 5, 2014 for such states should continue to be implemented.

The Committee reaffirmed that any polio-free state which becomes infected with wild poliovirus should immediately implement the advice for ‘States infected with wild poliovirus but not currently exporting’. In the event of new international spread from an infected state, that state should immediately implement the requirements for ‘States currently exporting wild poliovirus.’ The Committee noted that although a single wild poliovirus of Equatorial Guinea origin had been detected in Brazil in March 2014, Brazil was not considered polio-infected in the context of the global eradication initiative, as there was no evidence that this poliovirus exposure had resulted in transmission2. The Committee stressed the importance of surveillance in all polio-infected and polio-free countries.

The Committee acknowledged the efforts that affected states have made to address the temporary recommendations, and recognized the challenges experienced by affected states in their implementation. However, cognizant of the grave implications of any new international spread of poliovirus for the global eradication effort, the Committee considered whether additional temporary recommendations were needed at this time to further mitigate this risk. The Committee decided that additional time is first required to fully gauge the impact of the existing temporary recommendations in reducing the international spread of wild poliovirus. The Committee recommended, however, that this situation be reviewed again after three months.

Noting the challenges, both material and technical, that WHO member states had reported in implementing the temporary recommendations, the Committee emphasized the importance of continued support by WHO and the Global Polio Eradication Initiative partners toward the effective implementation and monitoring of these recommendations.

Based on this advice and the reports made by affected states, the director-general accepted the Committee’s assessment and declared that the international spread of wild poliovirus in 2014 continued to constitute a Public Health Emergency of International Concern (PHEIC). The director-general thanked the Committee Members and Advisors for their advice, requested their reassessment of this situation in three months and extended the following Temporary Recommendations under the IHR (2005), effective Aug. 3, 2014:

States currently exporting wild poliovirus

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;
- ensure that all residents and long-term visitors (i.e. > 4 weeks) receive a dose of OPV or inactivated poliovirus vaccine (IPV) between 4 weeks and 12 months prior to international travel;
- ensure that those undertaking urgent travel (i.e. within 4 weeks), who have not received a dose of OPV or IPV in the previous 4 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 travelers;
- ensure that such travelers are provided with an International Certificate of Vaccination or Prophylaxis in the form specified in Annex 6 of the International Health Regulations (2005) to record their polio vaccination and serve as proof of vaccination;
- maintain these measures until the following criteria have been met: (i) at least 6 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 at least 12 months have passed without new exportations.

States infected with wild poliovirus but not currently exporting

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;
encourage residents and long-term visitors to receive a dose of OPV or IPV 4 weeks to 12 months prior to international travel; those undertaking urgent travel (i.e. within 4 weeks) should be encouraged to receive a dose at least by the time of departure;
- ensure that travelers who receive such vaccination have access to an appropriate document to record their polio vaccination status;
- maintain these measures until the following criteria have been met: (i) at least 6 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 at least 12 months without evidence of transmission.

Source: WHO