WHO Convenes Emergency Committee About International Spread of Wild Poliovirus

The Emergency Committee of the World Health Organization (WHO) was convened by director-general Margaret Chan under the International Health Regulations (2005) April 28-29, 2014 to discuss the international spread of wild polioviruses.

Members of the Emergency Committee and expert advisors to the Committee met on both days of the meeting. The following affected WHO member states participated in the informational session of the meeting on April 28, 2014: Afghanistan, Cameroon, Equatorial Guinea, Ethiopia, Israel, Nigeria, Pakistan, Somalia and the Syrian Arab Republic.

During the informational session, the WHO Secretariat provided an update on and assessment of recent progress in stopping endemic and imported polioviruses and the international spread of wild polioviruses in 2014 as of April 26. The aforementioned WHO member states presented on recent developments in their countries.

After discussion and deliberation on the information provided, and in the context of the global polio eradication initiative, the Committee advised that the international spread of polio to date in 2014 constitutes an "extraordinary event" and a public health risk to other states for which a coordinated international response is essential. The current situation stands in stark contrast to the near-cessation of international spread of wild poliovirus from January 2012 through the 2013 low transmission season for this disease (i.e. January to April). If unchecked, this situation could result in failure 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) have been met.

At the end of 2013, 60 percent of polio cases were the result of international spread of wild poliovirus, and there was increasing evidence that adult travellers contributed to this spread. During the 2014 low transmission season there has already been international spread of wild poliovirus from 3 of the 10 states that are currently infected: in central Asia (from Pakistan to Afghanistan), in the Middle East (Syrian Arab Republic to Iraq) and in Central Africa (Cameroon to Equatorial Guinea). A coordinated international response is deemed essential to stop this international spread of wild poliovirus and to prevent new spread with the onset of the high transmission season in May/June 2014; unilateral measures may prove less effective in stopping international spread than a coordinated response. The consequences of further international spread are particularly acute today given the large number of polio-free but conflict-torn and fragile States which have severely compromised routine immunization services and are at high risk of re-infection. Such states would experience extreme difficulty in mounting an effective response were wild poliovirus to be reintroduced. As much international spread occurs across land borders, WHO should continue to facilitate a coordinated regional approach to accelerate interruption of virus transmission in each epidemiologic zone.

The overriding priority for all polio-infected states must be to interrupt wild poliovirus transmission within their borders as rapidly as possible through the immediate and full application in all geographic areas of the polio eradication strategies, specifically: supplementary immunization campaigns with oral poliovirus vaccine (OPV), surveillance for poliovirus, and routine immunization. The Committee provided the following advice to the director-general for her consideration to reduce the international spread of wild poliovirus, based on a risk stratification of the 10 states with active transmission (i.e. within the previous 6 months) as of April 29, 2014.

Pakistan, Cameroon, and the Syrian Arab Republic pose the greatest risk of further wild poliovirus exportations in 2014. 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 travellers 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.

Once a state has met the criteria to be assessed as no longer exporting wild poliovirus, it should continue to be considered as an infected State until such time as it has met the criteria to be removed from that category.

Afghanistan, Equatorial Guinea, Ethiopia, Iraq, Israel, Somalia and particularly Nigeria, given the international spread from that State historically, pose an ongoing risk for new wild poliovirus exportations in 2014. 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 have passed without new exportations.

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’. The WHO director-general should ensure an international assessment of the outbreak response is undertaken within 1 month of confirmation of the index case in any State which becomes newly infected. In the event of new international spread from an infected State, that State should immediately implement the vaccination requirements for ‘States currently exporting wild poliovirus’.

Based on this advice, the reports made by affected WHO member states and the currently available information, the director-general accepted the Committee’s assessment and on May 5, 2014 declared the international spread of wild poliovirus in 2014 a Public Health Emergency of International Concern (PHEIC). The director-general endorsed the Committee’s advice for ‘States currently exporting wild polioviruses’ and for ‘States infected with wild poliovirus but not currently exporting’ and issued them as Temporary Recommendations under the IHR (2005) to reduce the international spread of wild poliovirus, effective May 5, 2014.

Source: WHO