Islamabad(CNN) A string of deadly attacks in Pakistan targeting healthcare workers has sparked fears that the spread of misinformation is fueling a resurgence of violence against those attempting to rid the country of polio.

Attacks were reported on Monday in Bannu, Wednesday in Buner and Thursday in Quetta. One polio vaccination worker and two policemen have been killed.

Public health experts say there is concern that these attacks are exacerbating what is already one of the world's most intractable public health threats.

Pakistan is one of only three countries to have failed in its bid to stop the transmission of polio, according to the World Health Organization. That is in part due to a historical distrust of foreign healthcare providers, concerns that were inflamed after allegations surfaced that US intelligence officials had used a fake vaccination program in the Pakistani city of Abbottabad as part of efforts to capture Osama bin Laden in 2011.

Islamist militants have attacked and killed those attempting to distribute vaccines since the bin Laden revelation.

International NGOs and Pakistani authorities have worked aggressively to dispel rumors and vaccinate children in recent years. More than 20 million children were vaccinated in March of this year, according to Pakistani authorities.

In this picture taken on Monday outside Peshawar, Pakistani children look at a damaged health center local torched by a mob following rumors related to polio vaccinations.

But the omnipresence of smart phones and spread of social media has made it difficult to stop the spread of misinformation when it comes to polio eradication.

This week proved a telling example.

On Monday, reports that some students had a bad reaction to the polio vaccine spread like wildfire in the northern city of Peshawar.

"People rushed to the loudspeakers of nearby mosques barring people to stop polio drops to their children. They also suggested people to take their children to hospital immediately as some 'poisonous' material has been added to the vaccine," deputy police commissioner Muhammad Ali Asghar told CNN.

Following the reports, at least 25,000 students sought medical assistance, provincial health minister Hisham Inamullah said.

Not one child showed symptoms relating to the reports, had contracted a disease, or died after receiving the vaccine, said Inamullah.

Spreading 'fake news'

Yasmine Rashid, the public health minister for Pakistan's Punjab Province, said this week's developments have shown the country has to make a "concerted effort" to fight polio.

"Creating scares and spreading 'fake news' about polio drops may serve vested interests, but it's dealing a major blow (to our country)," she said.

Poliomyelitis, polio's formal name, is a highly infectious viral disease that is transmitted from person-to-person via the ingestion of contaminated feces, or through contaminated food.

Polio mainly affects young children. Fever, fatigue, headache, vomiting, stiffness in the neck and pain in the limbs are symptoms of the disease, which also can cause permanent paralysis.

The virus is easily preventable through immunization, but there's no cure once it is contracted.

The issue goes beyond Pakistan, the World Health Organization said late last year. The body announced that global progress in eradicating the disease had stalled and fears of a resurgence were rising -- much like what is occurring now with measles.