The UK’s last case of wild polio was in 1984 and the country was declared polio-free by the World Health Organisation in 2003,with low-risk for polio transmission due to the high level of vaccine coverage across the population.
Health experts believe the virus was probably imported from an individual who had recently been given an oral polio vaccine containing live virus,potentially in Nigeria,Pakistan and Afghanistan,which was then shed in faeces,entering London’s sewerage system.
The agency believes the traveller spread the vaccine-derived virus to “closely linked individuals” and there is now community transmission.
Loading
Polio can be spread by poor hand hygiene and,less commonly,through coughing and sneezing. The virus multiplies in the intestine and infected people excrete large quantities of it in their faeces for several weeks.
It causes paralysis in children in less than 1 per cent of cases. So far,there have been no reported cases of suspected polio,or unexplained cases of paralysis,but GPs and hospitals have been asked to look out for symptoms.
Wild polioviruses have been eradicated in most parts of the world except in Afghanistan and Pakistan,where they remain endemic.