Taliban militants have long been the scourge of Pakistan's polio vaccination campaign, attacking aid workers and the police who protect them as they distribute doses to children.
Consumed with protests
But experts say there is another reason for the sharp spike in cases of the crippling disease in Pakistan this year – government mismanagement.
The prime minister's polio cell was disbanded during 2013 elections, the new government delayed reconstituting it, and in recent months the prime minister has been consumed with protests in the capital that have only just ended.
"It's frustrating. Eradicating polio is not rocket science," said Elias Durry, head of the World Health Organisation's (WHO) polio campaign in Pakistan.
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"If we could have three to five months to have really good campaigns, then we could get rid of this disease," he said. "We have been doing half-baked campaigns in high risk areas."
Polio was meant be a thing of the past. A global campaign came tantalisingly close to wiping out the disease altogether.
Now polio, which can kill or paralyse a child in hours, is endemic only in Pakistan, Afghanistan and Nigeria. So far this year, Pakistan has had 217 polio cases, a 14-year high, accounting for 85 percent of instances around the world.
The disease spreads easily from person to person, and Pakistan has already exported the virus to Syria, China, Israel and Egypt. Experts say complacency is not an option and the government has called the situation an "emergency".
Yet as the latest vaccination campaign kicked off this week in the broiling, garbage-strewn alleys of Pakistan's biggest city, Karachi, vaccination workers said they had not received stipends from the provincial government for months.
Some have dropped out of the campaign in Karachi, a teeming city of 18 million people where the disease is entrenched.
As teams prepared to venture out on vaccination missions into some of Karachi's most dangerous streets, police deployed to protect them showed up late.
Vaccinators must wait, meaning they miss children. Sometimes only a third of children in an area are vaccinated, the WHO said, and low coverage fuels new outbreaks.
Read: New vaccination plan aims to rid world of polio
Pakistani Prime Minister Nawaz Sharif took six months to appoint an official responsible for polio, and the government approved a funding plan only last month.
That meant provinces did not pay workers their stipends of $2.50 a day on time, said Shahnaz Wazir Ali, a polio adviser to Sindh province in the south where Karachi is located.
"We had a loss of about nine to 10 months, which is a very big setback," Ali said.
Ayesha Farooq, the prime minister's appointee on polio, admitted there were problems, but said that payment arrears were down to provincial, not central government.
Lack of protection
Most new cases were in areas where security was poor so children had not been vaccinated, she said, and denied that Sharif was not taking the issue seriously.
"We have got to take responsibility for our weaknesses," Farooq told Reuters. "The quality of campaigns is something we will be paying close attention to."
For frontline polio workers, late pay is less worrying than lack of protection. Sixty-four people have been killed in attacks on polio teams and their security escorts since 2012, when the Taliban banned vaccinations in areas they controlled.
Their targets are women like 19-year-old medical student Asma Nizam, who received a death threat for taking part in the programme.
Read: Thirteen new Polio cases in Pakistan
"A man came on a motorbike and said, 'if you want to save your life, you should go from here'," she said.
The next day, militants killed five of her colleagues.
As she prepared to visit Karachi slums on a vaccination mission last Monday, police sent to protect Nizam were three hours late.
Pakistan's police are thinly spread, especially in crime-ridden Karachi where only 26,000 police watch over the huge city. Some are seconded as bodyguards for politicians.
"I have seen six police taking a VIP's teenager to the salon but they cannot spare any officers to protect the poor children of Pakistan," one health official burst out in exasperation.
Karachi police spokesman Atiq Shaikh said the force was severely understaffed.
"Polio campaigns take 2,000 officers. But we always provide them with security even though we have some time constraints," he said.
A further hurdle is caution among families offered the treatment. Some believe Taliban propaganda that says vaccinations are a Western plot to sterilise children.
Aiding polio's spread has been this year's military offensive in the tribal region of North Waziristan, which drove nearly a million people out of the conflict zone.
The mass movement allowed workers to vaccinate children previously unreachable. But families also moved to areas where vaccination coverage was patchy, allowing polio to reestablish itself in cities where it had been eradicated, experts say.
Malnutrition and diarrhoea
Children may need the oral vaccine up to 10 times for it to be effective. Many Pakistani children are malnourished or have diarrhoea so the vaccine is not absorbed.
The unlucky ones may end up like Rafia, a chubby two-year-old with kohl-rimmed eyes. Her legs were partially paralysed after contracting polio this summer.
"She was vaccinated whenever they came," said her father Ghulam Isaq, a shopkeeper. He massaged her tiny toes as a group of black-robed polio vaccinators looked on, only their eyes visible above black niqabs covering their faces.
"We need help even if we are poor," Isaq said. "We are Pakistanis too."
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Image: Stop polio sign from Shutterstock