West and Central Africa is on the brink of the largest polio epidemic in recent years, experts have warned.
The polio immunisation campaign was abandoned
The Global Polio Eradication Initiative says thousands of children are at risk of paralysis.
Five times as many children in the region have been hit by polio in 2004 as last year.
The upsurge has been linked to a suspension of the vaccination programme in northern Nigeria.
Last month a child was paralysed by polio in Darfur - the first case in Sudan for three years.
This means that ten countries have now been reinfected with the virus since the Nigerian state of Kano stopped immunisations for eight months last year after Islamic elders voiced concerns about vaccine safety.
They suspected vaccines had been adulterated as part of a western plot to depopulate the region.
It is hoped to resume a vaccination programme in the state using new supplies imported from Indonesia.
But since immunisations stopped 237 cases have been reported across West and central Africa, including 197 in Nigeria, compared to a total of 49 cases for the same period last year.
Mass immunisation campaigns, which will start in October, should reach 74m children in 22 countries.
But experts are worried, that with the high season for polio approaching, cases will begin to rise.
David Heymann, an expert in communicable diseases at the World Health Organization said: "There is no question that the virus is spreading at an alarming pace."
Polio, which mainly affects children under five, is caused by a virus that invades the nervous system and can cause total paralysis or death.
The Global Polio Eradication Initiative is hoping to rid the world of the disease by next year.
Only six countries worldwide - Afghanistan, Egypt, India, Niger, Nigeria, and Pakistan - are considered polio-endemic.
When the eradication drive was launched in 1988, polio was a serious problem in 125 countries.