In this report we summarise progress on polio prevention in Ireland and the remaining challenges that polio presents at an international level. The World Health Organization (WHO) continues to recommend vigilance and polio vaccination to prevent polio virus transmission. The Emergency Committee met for the seventh time in November 2015 and recommended that the temporary recommendations to stop the international spread of wild poliovirus (WPV) be extended for a further three months. In addition, the recommendations were expanded to apply to outbreaks of circulating vaccine derived polioviruses (cVDPV).
Polio is a highly contagious viral infection. It invades the nervous system, and can cause total paralysis in a matter of hours. The virus is transmitted by person-to-person spread mainly through the faecal-oral route or, less frequently, by contaminated water or food and multiplies in the intestine. Initial symptoms are fever, fatigue, headache, vomiting, stiffness of the neck and pain in the limbs. One in 200 infections leads to irreversible paralysis (usually in the legs). Among those paralysed, 5% to 10% die when their breathing muscles are affected.
In Ireland, since 1957, when the routine polio vaccination programme began, all children have been recommended polio vaccination. The last case of polio notified in Ireland was in 1984. (Figure 1).
Figure 1: Number of polio cases notified in the Republic of Ireland 1948 - 2014, and year of vaccine introduction
In 2001, Ireland switched from giving the attenuated live oral polio vaccine (OPV), given as drops, to an inactivated polio vaccine (IPV) which is given as an injection. The reason we changed vaccine was because of a very rare risk of vaccine associated paralysis occurring among recipients of the oral polio vaccine (estimated to occur in about 1 recipient of OPV vaccine for every 2 to 3 million doses of OPV administered).
The IPV is given as part of the “6-in-1” vaccine which is given to babies at 2, 4, and 6 months of age. The “6-in1” vaccine contain vaccines against diphtheria, tetanus, pertussis, Haemophilus influenzae type B disease (Hib), hepatitis B, as well as polio (DTaP-Hib-IPV-HepB). Most Irish children complete their primary vaccination with the “6-in1” vaccine. In Quarter 2, 2015, 95% of children had received three doses of the IPV by 24 months of age.
But in some countries with poorly functioning polio vaccination programmes or poor uptake of polio vaccine children are at continued risk of polio from polio virus.
Ongoing international transmission of wild polio virus and circulation of vaccine derived polio viruses (cVDPV) - Public Health Emergency of International Concern (PHEIC)
In April 2014 the International Health Regulations Emergency Committee of WHO met regarding the international spread of poliovirus during that year and recommended temporary recommendations to stop the international spread of wild poliovirus (WPV). These temporary recommendations were further amended in November 2015 (Seventh Meeting of Emergency Committee) to address the continued transmission of wild polio virus in Pakistan and Afghanistan and the emerging issue of circulating vaccine derived polio virus (cVDPVs) among poorly vaccinated populations (notably including Lao People's Democratic Republic, Madagasgar, Myanmar, Guinea, Nigeria and Ukraine).
An extract from the temporary recommendations summarises the relevant points for Irish residents:
Temporary recommendations extension (November 2015)
States currently exporting wild poliovirus or cVDPV
(Currently Pakistan (last wild poliovirus exportation: 27 August 2015) and Afghanistan (last wild poliovirus exportation: 6 June 2015).)
- 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 to record their polio vaccination and serve as proof of vaccination.
States infected with wild poliovirus or cVDPV but not currently exporting
(Currently (any cVDPV detected within preceding six months) Nigeria, Guinea, Madagascar, Ukraine, and Lao People’s Democratic Republic.)
These countries should:
- 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.
Further detail is available from WHO - http://www.who.int/mediacentre/news/statements/2015/ihr-ec-poliovirus/en/
Recommendations for Irish residents
- All individuals in Ireland, regardless of travel, should ensure that they are fully vaccinated against polio.
- All travellers to countries where polio transmission has been reported (wild polio or circulating vaccine derived polio viruses) should be fully vaccinated prior to travel.
- For further information on countries where polio has been identified please go to the WHO page located at http://www.polioeradication.org/dataandmonitoring/poliothisweek.aspx
Further information on polio is available at:
Suzanne Cotter, HPSC
