Polio was eliminated in the Asia-Pacific. Then it suddenly came back - ABC News

Posted: 13 Jun 2021 02:00 PM PDT

One morning in April 2018, six-year-old Gafo woke up with aching legs.

"Thursday morning he woke up from bed, he said his leg was hurting and he fell over," his dad Maya told 7.30.

Gafo loved playing soccer and touch footy and had been excited to play with his friends.

But on this day, Maya found his son struggling to get off the bedroom floor of their home on the outskirts of Papua New Guinea's semi-rural city of Lae.

Unsure of what was wrong with him, Maya and Gafo's mum, Soya, massaged their son's legs and let him rest.

Play Audio. Duration: 40 minutes 30 seconds

Despite their best efforts, Gafo's condition didn't improve.

He was unable to walk or even stand up.

Maya and Soya took Gafo to a hospital in Lae where he was diagnosed with acute flaccid paralysis or AFP, a syndrome characterised by the sudden onset of muscle weakness in the limbs.

AFP has many causes, so to get a clear diagnosis, Gafo's doctors sent a stool sample away for further testing.

When the result came back, it took Gafo's parents — and many others — by surprise.

"When [the doctor] said polio, at the time, we didn't know what this illness was," Maya says.

A young boy holding a soccer ball, sitting with his mum and dad in the outdoors. — Gafo's legs became so weak that he could barely move.(
ABC News: Natalie Whiting
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Papua New Guinea had been polio-free for almost two decades.

"Afterwards, the doctors explained that this sickness doesn't have a medicine to cure it," he says.

A disease from another era

Polio is a highly infectious viral disease that mainly affects children under the age of five.

The virus is transmitted through the faeces and saliva of an infected person — often passed on via contaminated hands, food, or water — before it makes its way into somebody's gut.

A little girl looks at a needle as she prepares to get the polio vaccine next to a school sign in the 1950s. — In the early 20th century, polio was one of the most feared diseases.(
Getty Images: H Armstrong Roberts/ClassicStock
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Most people infected with polio show no symptoms; the ones that do generally get a flu-like illness.

But in rare cases, the virus invades the nervous system, leaving one in 200 people with irreversible paralysis.

In the first half of the 20th century, polio killed thousands of children, left many with a disability, and struck fear into the hearts of parents all over the world.

Fortunately, in 1955, an American scientist named Dr Jonas Salk developed an effective polio vaccine that saw cases drop dramatically.

Dr Jonas Salk stands in the University of Pittsburgh laboratory in which he developed a vaccine for polio. — Dr Jonas Salk developed the first polio vaccine almost 70 years ago.(
Getty Images: Bettmann
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A few years later, another vaccine arrived from Polish-American scientist Dr Albert Sabin, which proved even more effective.

The combination of vaccines opened up the possibility of global eradication, and in 1988 the World Health Organisation launched a campaign to do just that.

The campaign has been hugely successful: polio cases have dropped more than 99 per cent globally, and all but two countries — Afghanistan and Pakistan — have been declared polio-free.

So how, after 18 years, had the disease suddenly made its way back into Papua New Guinea?

'That's when we realised we had a problem'

Soon after Gafo's diagnosis, PNG's Department of Health got to work trying to identify additional cases and contain the virus before it spread further.

International aid workers were called in and emergency operation centres were set up across the country.

Three men standing to the right of a mobile polio vaccination clinic. — Health authorities quickly organised new rounds of vaccinations to stop the spread of the virus.(
Getty Images: Peter Parks/AFP
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Mathias Bauri, who was managing PNG's national immunisation program, says health workers began testing Gafo's family, friends, and others in the community where he lived.

"We were crossing our fingers," says Dr Bauri, director of public health for PNG's Western Provincial Health Authority.

Unfortunately, they detected polio in the stool samples of two other children.

As health officials worked to bring the outbreak under control, they were notified of another case across the Indonesian border in the disputed province of West Papua.

A two-and-a-half-year-old boy had developed leg paralysis and tested positive for polio.

By February 2019, the detection of two additional cases in children in the same region led Indonesian health authorities to declare that poliovirus was circulating.

And its resurgence didn't stop there.

From PNG to the Philippines

In September, health authorities in the Philippines discovered a three-year-old girl named Junaisa, who hadn't been able to stand up or walk on her own since June.

"Her mother recalled … she had always been energetic and active until that day when she could not stand anymore," says Jun Orbina, a communications officer for the WHO Philippines.

Junaisa's parents, Salma and Haimer, had spent months taking her from hospital to hospital, hoping that someone could tell them what was wrong.

"That caused a lot of alarm … they could not attach any name or definition to what Junaisa had been experiencing," Mr Orbina says.

Two parents sitting holding two of their children. — Junaisa hadn't received the full three doses of the polio vaccine.(
Supplied: WHO/F Tanggol
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Junaisa was the first child to be diagnosed with polio in the Philippines in almost two decades.

Malaysia — right next door — was immediately put on high alert.

The Malaysian Ministry of Health wrote to clinicians warning them to look for and report any cases of AFP, says Waheed Miraj, a doctor who was working with the WHO Malaysia.

In December, a doctor in the state of Sabah, which shares a border with the Philippines, sounded the alarm.

"This case was notified as the first polio case since 1992 in Malaysia," Dr Miraj says.

"After that, we had three more children as well."

In just 18 months, polio had reemerged in four countries across the Asia-Pacific, a region long considered polio-free.

Where did the virus come from?

Using genomic testing, scientists were able to trace each outbreak back to a "vaccine-derived poliovirus" — in other words, a strain that originated from the weakened but live virus contained in the vaccine, which was then excreted by someone into the community, where it spread.

A photomicrograph of the lumbar spinal cord depicting an infarct due to Polio Type III surrounding the anterior spinal artery. — Over time, the vaccine-derived virus can replicate, regain strength and destroy nerve cells, causing paralysis.(
Supplied: CDC/Dr Karp, Emory University
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On rare occasions, if a population is seriously under-immunised, an excreted vaccine virus can circulate for a prolonged period.

This allows it to pick up a lot of genetic changes, and in rare instances, mutate into a form of the virus that can cause paralysis.

Vaccine-derived polio outbreaks are only a risk in places where sanitation is poor and where the oral polio vaccine, or OPV, is still being used.

That's because the OPV (unlike the inactivated polio vaccine, or IPV) is a live attenuated vaccine, meaning each drop contains a tiny, weakened virus.

A drop from an oral polio vaccine about to go into a child's mouth. — The oral polio vaccine, developed by Albert Sabin, is given as a drop of liquid in the mouth.(
Getty Images: Haroon Sabawoon/Anadolu Agency
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Despite the small risk of vaccine-derived outbreaks, the oral polio vaccine is still being used in several countries because it has other major advantages, epidemiologist Meru Sheel says.

"One of the reasons why we use the oral polio vaccine is because it's highly immunogenic — it creates a strong immune response," says Dr Sheel of the Australian National University.

Not only does it provide a strong immune response, it's also cheap, easy to deliver, and, unlike the IPV, it interrupts the transmission of polio, so it's recommended in countries where polio is still a threat.

WHO workers going village to village in Philippines — WHO workers travel village to village in the Philippines to administer polio vaccines.(
Supplied: WHO
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Virus spreads undetected for years

In PNG, vaccination rates were low, virus surveillance was weak, and sanitation was poor in areas like the one where Gafo lived.

This combination left the country vulnerable to a vaccine-derived outbreak.

"The recommended immunisation vaccination coverage for polio is 95 per cent," Dr Sheel says.

"Papua New Guinea at the time was at about 66 per cent … which essentially meant that the immunisation was not enough to prevent the transmission of the virus."

Testing of Gafo's stool sample revealed the poliovirus he'd contracted had been circulating unchecked for approximately two years.

With so much time to spread, the virus had made its way through several PNG provinces.

A doctor speaking to a crowd of people, many of whom are sitting on the ground. — Problems can occur with the oral polio vaccine when immunity levels in the community are very low.(
Supplied: WHO/Renagi Taukurai
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Across the border in Indonesia, low immunisation rates in remote villages had left the region vulnerable, and a vaccine-derived poliovirus found a foothold there too.

The outbreaks in the Philippines and Malaysia weren't connected to PNG or Indonesia, but they were connected to one another.

Genomic testing of the vaccine-derived virus in Malaysia revealed it had been circulating for about five years.

But it's not clear whether it first emerged there, or in the Philippines.

In the region where the maritime borders of the two countries meet, movement is part of everyday life.

Many people live on the water, drifting between the two countries for trade and travel.

Huts sitting in on silts in the water as people wander past. — The conditions in this porous border region were ideal for a vaccine-derived poliovirus to flourish.(
Supplied: WHO
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On the Malaysian side of the border, Dr Miraj says government policies make it expensive and difficult for non-citizens to seek basic health care — including vaccinations — leaving a significant proportion of the population unvaccinated.

In the Philippines, access to health services — and even proper sanitation — had been impacted by a conflict in 2017.

Following the outbreaks, governments in each country launched mass vaccination campaigns to try to catch any children who'd missed out.

Since 2020, there's only been one case of polio in the Philippines and one in Malaysia. And there have been no new cases in Indonesia or PNG, where the outbreak is no longer considered active.

On the cusp of global eradication

A man with polio who lives in a Manila junkyard shows how his legs have been affected. — The man shows how his legs have been affected by polio.(
Supplied: WHO/Yoshi Shimizu
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Polio is a disease on the cusp of global eradication, but there are still some major challenges that stand in the way.

Today, vaccine-derived polio cases outnumber wild polio cases — the ones that occur in the few places where polio is still endemic. But the solution isn't simple.

Oral polio vaccines still need to be used whenever there are polio outbreaks, because they're the only way to stop transmission.

But with each use comes the potential to seed more vaccine-derived viruses.

Fortunately, a new, more stable oral polio vaccine has been developed, which is less likely to mutate and which researchers hope is a key piece of the puzzle to achieving eradication.

Close-up image of child being given oral polio vaccine in Afghanistan. — Vaccine-derived outbreaks have emerged not only in the Asia Pacific, but in Afghanistan, Pakistan and many parts of Africa.(
Reuters: Parwiz
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The other key piece: eradicating the virus in Afghanistan and neighbouring Pakistan, the only two countries in the world still fighting against wild polio.

Neither has ever been able to immunise enough people to completely eliminate the virus.

This is partly because health workers often struggle to deliver vaccines in areas of conflict, says Dr Miraj, who lives and works in Pakistan.

A policeman stands guard with a gun as a child is given the polio vaccine in Pakistan, — In some places, vaccinators have been banned by the Taliban from doing polio vaccination drives.(
Reuters: Akhtar Soomro
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Even in areas that are accessible, high rates of vaccine hesitancy — often fuelled by conspiracy theories and misinformation — can also be a problem.

"Facebook is the main social media that is being used in Pakistan and Afghanistan. So the negative news spreads quite fast," Dr Miraj says.

This hasn't been helped by dubious real-life events.

In 2011, the CIA organised a fake vaccination campaign, sending nurses door to door offering free vaccinations to children for hepatitis B.

The health workers were instructed to secretly collect DNA samples from the vaccinated children in the hopes they could track down Osama bin Laden's family in hiding.

An assortment of posters of former Al Qaeda leader Osama bin Laden. — Then Al-Qaeda leader Osama bin Laden was shot dead by US Navy SEALs in 2011.(
Getty Images: Patrick Aventurier/Gamma-Rapho
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When the truth eventually came out, it sent shock waves of anger through the region and exacerbated distrust towards vaccines.

The eradication of polio has been thrown another curveball recently in the form of a pandemic.

"We've seen this in many parts of the world, where immunisation systems have been disrupted due to COVID for various reasons," Dr Sheel says.

Since the start of the pandemic, cases of both wild and vaccine-derived polio have risen around the world.

In 2019, there were 554 cases of paralytic polio globally. In 2020, that figure more than doubled to 1,216.

In PNG, the coronavirus pandemic pushed polio vaccinations back considerably, Dr Bauri says.

"COVID-19 has disrupted other programs as well; not only immunisation, but tuberculosis, malaria programs, sanitation.

"People might be at risk of other diseases, especially children."

Gafo's dreams for the future

Gafo's parents spent six months looking after him while he was unwell, staying up late at night to make sure he did his physical exercises.

"I told him, 'there is life inside of you, so don't you worry'. I kept stretching his arms and legs," Maya says.

After months of physical therapy, Gafo began walking on his own.

Play Video. Duration: 10 seconds — Gafo is recovering from polio

But he continues to suffer the burden of being the first child diagnosed in PNG in almost 20 years. His parents worry about his future.

"I don't want the other children to say he is a sick person, he is a polio person. I don't want that to hurt his feelings," Soya says.

Gafo says he's doing a lot better.

"They give me medicine; my hands and legs are OK, and I am happy walking around and now I will go to school."

When asked what he wants to study for, Gafo doesn't hesitate.

"Doctor."

Additional reporting by Natalie Whiting and Bethanie Harriman.

This story comes from Patient Zero, an eight-part series about disease outbreaks. Listen for free wherever you get your podcasts.

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