GENEVA: Pakistan and Afghanistan must intensify efforts to halt spread of the crippling poliovirus, including better screening of travellers heading abroad, the World Health Organization said on Monday.
Pakistan and Afghanistan - the only two countries where the poliovirus remains endemic - have reported 29 and seven cases, respectively, so far this year, against 108 and eight at this time in 2014, WHO spokesperson Sona Bari said.
The WHO emergency committee of experts in a statement, while recognising progress in Pakistan, said that its residents lacking documentation of recent polio vaccination should be restricted "at the point of departure", whether travelling by road, air or sea.
The committee had convened a meeting on August 4, 2015, to review international spread of wild poliovirus during which the 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.
While appreciating the strong progress made by Pakistan towards 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, it said that the virus was still prevalent in the country, accounting for 85% of all polio cases recorded worldwide.
However, while no export of the virus from Pakistan had been detected since October 21, 2014, several countries still require proof of polio vaccination from travellers out of Pakistan and Afghanistan at points of entry.
“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.”
Two cases of poliovirus exported to Pakistan
The committee noted that the international spread of wild poliovirus has continued, with two new documented exportations from Afghanistan into Pakistan in 2015.
The poliovirus found in Pakistan were closely related to strains recently circulating in Afghanistan than to those currently found in Pakistan.
One of these cases occurred in Quetta, near the Afghanistan-Pakistan border. But worryingly the second case was found in a district of Sindh, an area that is quite far from the Afghan border.
This case, the committee said, underlines the risk of distant international spread from zones of poliovirus transmission.
The committee was concerned that the temporary recommendations for international travellers of all ages were not being implemented fully in Afghanistan – particularly at airports.
“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,” it recommended.
Under the IHR, spread of poliovirus between two member states, i.e. Pakistan and Afghanistan, constitutes international spread.
The committee further recommended that coordination and quality of cross-border vaccination and surveillance activities should be further strengthened to reduce the risk of this international spread.
Afghanistan needs to track international travellers better
It said that vaccinations of international air travellers in Afghanistan are not being tracked "and no exit screening and restriction of unvaccinated travellers has been implemented at international airports".
"The increasing risk of international spread associated with the ongoing suspension of mass vaccination campaigns in Kandahar province was another major source of concern," the UN agency said, referring to Taliban factions that have halted vaccination campaigns.
"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 (Pakistan and Afghanistan) must achieve interruption of poliovirus transmission simultaneously in order to prevent such international spread from repeatedly setting back progress."
India, which had its last case in 2011, was certified polio-free three years later.
The poliomyelitis virus attacks the nervous system and can cause irreversible paralysis within hours of infection. It often spreads among young children and in areas with poor sanitation.
In Africa, no cases of wild poliovirus have been reported since Somalia on August 11, 2014, Bari said. Nigeria marked its first year without a single case on July 24, reaching a milestone many experts had thought would elude it as internal conflict hampered the battle against the disease.
Hot spots in the Middle East, the Horn of Africa and central Africa, particularly the Lake Chad region bordering Nigeria, remain vulnerable to polio, the WHO said: "The hard-earned gains can be quickly lost if there is continued disruption of health systems."
Madagascar has had nine cases of vaccine-derived poliovirus this year, against one in 2014, Bari said. The outbreak stems from a "very rare mutation" of the virus into a paralytic form after passing through the stool of a person who has had the oral vaccine, usually into an environment with low immunity, she said.
Temporary recommendations: States currently exporting wild poliovirus
It also made eight temporary recommendations for Pakistan (last exportation: 21 October, 2014) and Afghanistan (last exportation: 6 June 2015):
- 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.
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