NEW DELHI: Indian health workers are investigating two new suspected cases of polio in the impoverished east, a year after the country celebrated eradication of the crippling virus, an official said Monday.

The boys, both aged two, from neighbouring villages in Bihar state have been isolated after developing fever and severe weakness in their limbs earlier this month, leaving them unable to walk, the official said.

Uday Kumar Choudhary, chief medical officer for Darbhanga district, where the children live, said they were suffering from acute flaccid paralysis, a medical condition often connected to polio.

“We have sent the samples for testing and the results are expected in a few days. We cannot say anything now,” Choudhary told AFP over phone from Darbhanga. “Both the children have been isolated. We hope it turns out to be negative,” he added.

Suspected polio cases are occasionally reported from rural and normally underdeveloped areas of India but the country has not reported a positive case since 2011 after a mammoth and successful years-long vaccination programme.

The World Health Organisation officially certified India and 10 other Asian countries free of polio last March, hailed as a “momentous victory” after the country went three years without reporting a new case.

India's poor sanitation, mass internal migration and dilapidated public health system made many experts believe it would be the last country to eradicate the disease, if at all.

Despite its success in tackling the disease, the wretched sight of crippled street hawkers or beggars on wheeled trolleys will endure in India as a legacy of the country's time as an epicentre of new cases.

The polio virus spreads through faecal matter, attacks the central nervous system and can leave its victims crippled or dead.

There are now only three countries where polio is still endemic — Pakistan, Afghanistan and Nigeria.