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New Delhi, November 30, 2018:
The nineteenth meeting of the Emergency Committee under the International Health Regulations (2005) (IHR) regarding the international spread of poliovirus was convened by the Director General on 27 November 2018 at WHO headquarters with members, advisers and invited Member States attending via teleconference.
The Emergency Committee reviewed the data on wild poliovirus (WPV1) and circulating vaccine derived polioviruses (cVDPV). The Secretariat presented a report of progress for affected IHR States Parties subject to Temporary Recommendations. The following IHR States Parties provided an update on the current situation and the implementation of the WHO Temporary Recommendations since the Committee last met on 15 August 2018: Afghanistan, Democratic Republic of the Congo (DR Congo), Nigeria, Niger, Papua New Guinea (PNG), and Somalia.
Wild polio
The Committee commended the continued high level commitment seen in Afghanistan and Pakistan, and the significant degree of cooperation and coordination, particularly in reaching high risk mobile populations that frequently cross the international border. The committee noted that it is four years since there has been international spread outside of these two epidemiologically linked countries.
However, the Committee was very concerned by the increase in WPV1 cases globally in 2018, especially regarding the increased number of WPV cases in Afghanistan. Furthermore, after a 10-month period of no international spread of wild poliovirus between the two neighbors, Pakistan and Afghanistan, cross border spread in both directions has occurred in the last three months.
In Pakistan the situation in 2018 has stagnated, with the number of cases so far at the same level in 2018 as for the whole of 2017. Furthermore, positive environmental isolates in 2018 continue to be widely spread geographically indicating multiple areas of transmission and missed susceptible population groups. Nevertheless, the performance of the eradication program has shown some improvement in areas such as SIA quality.
In Afghanistan, the number of polio cases has almost doubled in 2018, with 19 cases reported so far, compared to 10 at the same time last year, due to worsened security and greater inaccessibility, and persistent pockets of refusals and missed children. Environmental surveillance is also finding an increased proportion of positive samples. The security situation and access would need to significantly improve for eradication efforts to progress, as currently 1 million children under 5 years old are inaccessible in recent polio immunization campaigns.
It is now more than two years since the last WPV1 was detected in an accessible area of Nigeria, and four years since there has been any international spread of WPV1 from the country. The Committee commended the strong efforts to reach inaccessible and trapped children in Borno, Nigeria, even in the face of increased insecurity, and noted that the inaccessible target population was now down to around 70,000 children, scattered across Borno in smaller pockets.
Vaccine derived poliovirus
The outbreaks of cVDPV2 in Somalia, Kenya, DR Congo, Niger and cVDPV1 in PNG and cVDPV3 in Somalia continue to be of major concern, particularly the apparent international spread between Somalia and Kenya and the recent spread from Nigeria into Niger of cVDPV2, given that traditionally cVDPV viruses have rarely spread across borders. Conflict and population movement within and outside DR Congo indicate a degree of risk of spread.
Large inaccessible areas of Somalia are a significant constraint on achieving interruption of transmission of the cVDPV2 and cVDPV3 in the area, exacerbated by large population movements into and out of these areas.
Nevertheless because of the limited supply of IPV, in cVDPV type 2 outbreaks the implementation of the Temporary Recommendations for border immunization of departing travelers can be difficult. The committee noted the progress made with cross border cooperation between PNG and Indonesia, but was concerned that new cases of cVDPV1 in new provinces of PNG had been detected in the last three months, and that surveillance indicators in Indonesian provinces neighboring PNG were sub-optimal. Similarly, countries neighboring Somalia, such as South Sudan, Ethiopia and Djibouti, have areas of weak surveillance which poses the risk that international spread may go undetected. The outbreak of cVDPV2 in Syria has been successfully controlled with no international spread, and Syria is no longer considered infected but remains vulnerable.
The committee noted that in all infected countries, routine immunization was weak. The outbreaks of cVDPV2 in Jigawa, and for the second time in Sokoto, Nigeria, again underlines the vulnerability of northern Nigeria to poliovirus transmission. Routine immunization coverage remains very poor in many areas of the country, although the political leadership and national emergency programme to strengthen routine immunisation is beginning to make an impact in some areas.
