Pakistan has detected a record number of polio case already this year, a senior government official has said.

In all, doctors have discovered 202 cases from January of this year to October 3. The previous modern record was 199 cases in 2001.

"We are sad to announce that the number of polio cases is now all-time high in Pakistan," Rana Mohammad Safdar, a senior official at the National Institute of Health in Islamabad, told the AP news agency.

Pakistan, Afghanistan and Nigeria are the only three countries in the world where polio remains endemic. The highly contagious virus is transmitted in unsanitary conditions but is easily fended off with a vaccine.

Attacks on polio workers

However, efforts to eradicate it are hampered by the Taliban, which have banned immunisations and have attacked polio vaccination teams across Pakistan, while accusing doctors of being spies and sterilising boys.

Fighters stepped up attacks on polio workers after it was revealed that a Pakistani doctor, Shakil Afridi, offered a programme of hepatitis vaccinations in the northwestern city of Abbottabad as part of his CIA-backed efforts to obtain DNA samples from children at a local compound where Osama bin Laden live.

About 60 polio workers or police escorting polio teams have been killed in Pakistan since 2012, Safdar said.

"New polio cases are surfacing because of those children who could not be immunised against the disease in tribal regions," he said. "We were expecting this alarming increase in polio case."

Safdar said Pakistan this week again launched a nationwide anti-polio drive in an attempt to get all of Pakistan's 34 million children vaccinated.