Historical Photo: Polio vaccine comes to Norway in October 1956
Wild poliovirus type 1 is circulating in China. The virus is genetically related to the poliovirus strain that is currently circulating in Pakistan. The situation in China and Pakistan highlights the importance of adequate vaccination for children and adults travelling to areas where poliomyelitis is endemic.
Up until summer 2011, 57 poliomyelitis cases caused by wild poliovirus type 1 were reported in Pakistan. Chinese and Pakistani health authorities have initiated mass vaccination campaigns in the affected areas. Poliomyelitis is endemic in Pakistan, India and Afghanistan. Work to globally eradicate poliomyelitis is considered to be in a final phase, but it is challenging to vaccinate children in poor and densely populated areas in India and in the conflict areas on the border between Pakistan and Afghanistan.
Since 1975, five imported cases of poliomyelitis caused by wild poliovirus have been reported in Norway (1975, 1981, 1982, 1987 and 1992). Three of the patients were infected in Pakistan. Two of the cases were adults, two were immigrant children who had visited their parents’ homeland, and one case was an adopted child from abroad. None of these cases led to the spread of infection within Norway.
Both children and adult travellers to poliomyelitis endemic areas should be adequately vaccinated. Booster doses are recommended if more than ten years have elapsed since the last dose. People who have been previously vaccinated will be protected after a single booster dose, even if it has been many decades since the last vaccine dose. It is especially important that children and adults who travel from Norway to visit relatives and friends in their former homelands in endemic areas (e.g. Pakistan), are adequately vaccinated against poliomyelitis.
The decision to take small children on trips to tropical and subtropical regions must be based on an overall assessment of what is best for the child. Before travel, children should receive the first vaccine doses against diphtheria, tetanus, pertussis, poliomyelitis and Haemophilus influenzae infection (DTP-IPV-Hib vaccine). They should also have been immunised against measles, mumps and rubella (MMR vaccine). Normally, this means that the child should be over 15 months old but in special situations where younger children will have a longer stay in the tropical or subtropical areas (e.g. relocation), it may be necessary to give three doses of DTP-IPV-Hib vaccine with a short interval. The first dose can be given as early as 6-8 weeks of age and there must be a minimum of four weeks between each of the three doses. The first dose of MMR vaccine can be given at 9 months of age at the earliest.