What does it take to wipe out a human disease?
That's only happened once in the history of the world: smallpox, which had killed hundreds of millions, was officially eradicated in 1980.
But it happens on a smaller scale every year. In 2024, nine countries eliminated a disease.
"These are great accomplishments that have been achieved with very limited means," says Albis Gabrielli, who works for the World Health Organization's global neglected tropical disease program and oversees their monitoring and evaluation work. WHO certifies an elimination either when a country gets rid of the disease entirely or brings it to such low levels that human health is not affected in any significant way.
Here's a list of this year's honors. Cape Verde and Egypt became malaria-free. Brazil and Timor Leste eliminated lymphatic filariasis, the disfiguring parasite that causes a condition commonly known as elephantiasis. Jordan became the first country to ever be certified as leprosy-free. Chad got rid of one form of human African trypanosomiasis or sleeping sickness. And Pakistan, Vietnam and India eliminated trachoma, which causes blindness.
And even though each achievement is just one disease in one country, the effort can be daunting — as illustrated by the story of Pakistan's more than 20-year battle to wipe out trachoma, a goal that just a few years ago seemed out of reach.
"It's a massive effort that required mobilization of hundreds or thousands of health-care workers and other personnel," says Anthony Solomon, chief scientist for the World Health Organization's global neglected tropical disease program.
'I just wished I could do something'
Wiping out trachoma was a childhood dream for Asad Aslam Khan.
As a young boy, on visits to his father's village outside of Lahore, Pakistan, he'd see the rice, sugar cane and wheat fields stretch out before him. But the image he couldn't get out of his mind: All the people who could no longer work in the fields.
"They had red eyes, watery eyes. They were in pain," he remembers. "It was a miserable situation."
The source of their pain was a condition called trachoma. It's a bacterial infection and when someone is infected repeatedly — upward of 100 times — it can cause their eyelashes to turn inward and scratch the surface of the eye. It's painful and can cause blurred vision and, eventually, irreversible blindness. For nearly 2 million people around the world, trachoma leads to visual impairment.
"I used to feel very bad for these patients in pain," Khan recalls. "I just wished I could do something for those poor people."
Now, more than 50 years later, Khan has done something. He's led Pakistan's initiative to eliminate trachoma as a public health problem. "And, by the grace of almighty Allah, we now have become a trachoma-free country," says Khan, who is an ophthalmologist and has been the chairman of the Ministry of Health's National Trachoma Task Force for more than 20 years.
'It makes them poorer'
When Pakistan set out to eliminate trachoma, it followed a strategy used by more than a dozen other countries that had already wiped out the disease.
The first prong: Relieve the pain. This involves surgery in which the eyelashes are repositioned so they no longer scratch the cornea. It's "a very simple procedure that can be done by eye nurses or general doctors," says Solomon of WHO. Not only can it preserve any remaining vision but it "certainly improves quality of life, regardless of its effect on vision, because the sensation of having eyelashes scratching on the surface of your eye is incredibly painful."
Second, stop the bacteria. Blindness usually comes later in life but most of the infections that cause it come in early childhood. Experts say a person needs to be infected about 150 times to go blind. And most of those infections happen to preschool-aged kids who "are infected every week or every couple of weeks," Solomon says.
To stop those infections and interrupt the spread, health workers administer the antibiotic azithromycin — often the pill is given once a year for several years. The doses have been donated by the pharmaceutical company Pfizer Inc. – which has given more than one billion doses toward trachoma elimination globally — and are given en masse to everyone in an area impacted by trachoma. The pills are given in schools, in mosques and door-to-door.
Third, prevent infection. The bacteria spread through contact. Kids may touch the infected discharge from a friend's eye or nose or the bacteria can travel through shared beddings or hard surfaces. Flies can spread it from one person to another too. The best way to prevent it is through improving facial cleanliness and environmental cleanliness.
The challenge here is that the places where trachoma is most common often don't have clean water and working sewage systems. "It affects the poorest people in the world and makes them poorer," says Solomon.
And that's exactly what Khan remembers of his father's village. "It spreads very easily in overcrowded spaces, where in a single room 10 to 20 people are living, and they don't [have water to] wash their hands, they don't wash their faces," he says.
The solution is to help rural villages and poor urban areas get access to running water, latrines and toilets – and then teach people about washing their face with soap regularly and clearing discharge from the nose or eye that might contain the bacteria.
But, in Pakistan, as the trachoma elimination teams started building toilets and latrines, there was resistance. Initially, many people used to open defecation were "reluctant" to use toilets, says Munazza Gillani, who is director for Pakistan and the Middle East at the charity Sightsavers. The group has played a key role in Pakistan's work to eliminate trachoma and she serves on the National Trachoma Task Force.
"They found it really strange to have a toilet within their homes, and they thought it's not a hygienic practice," she recalls. She says her team decided to start by putting toilets in mosques, schools and other communal gathering spots so people could become accustomed to using them. "When they started using it, they realized the comfort and the improvement in their quality of life," Gillani says.
To teach people about facial cleanliness, she says, they turned to theatrical performances at schools. "It's a fun way to attract the child's attention," she says. "And the children were also used as messengers and ambassadors to spread the education and awareness back home."
By 2019, the process was in full swing. There were door-to-door surveys to assess the prevalence of trachoma and identify hot spots. Optometrists and community health workers were trained. Teams of people administered the antibiotics.
But then, typhoid interrupted their progress. And, it wasn't just any typhoid. Extensively drug-resistant (XDR) typhoid was on the rise in Pakistan.
'It was very surprising'
What connects XDR typhoid and trachoma? Azithromycin.
It's the antibiotic used to fight off the bacteria that causes trachoma. It's also the only oral medication that was working against XDR typhoid in Pakistan.
Since typhoid is a brutal, life-threatening disease, many wanted to stop the mass use of azithromycin for trachoma elimination and "preserve that effectiveness against typhoid because people will die today, tomorrow, next week from typhoid. They don't die from trachoma," says Solomon, the WHO scientist.
All the trachoma experts in Pakistan gathered to figure out what to do. After long and painful discussions, they paused the use of the antibiotics for trachoma.
"We were very much demoralized. If we can't distribute the antibiotics, how can we control active trachoma?" Khan recalls thinking. Although, he adds, they knew it was the right thing to do.
"We switch over to focus more on the facial cleanliness and environmental hygiene," he says, redoubling school sessions and building more sample latrines in village centers.
Experts braced themselves. "We had this fear that [elimination] might take a long, long time," says Gillani of Sightsavers, adding that "Pakistan is such a big, huge country with so many geographically scattered health facilities."
After more than a year without azithromycin distributions, the National Trachoma Task Force did a survey to see where things stood. The results shocked them.
"It was very surprising to see that none of the districts reported any new active trachoma cases," says Gillani.
Khan remembers marveling that the water and sanitation improvements "gave us very, very good results."
"So that was the starting point when we all sat together and we decided: Now it's the time to get prepared for the elimination dossier," says Gillani.
'Everyone was so happy'
They started gathering all the data they'd need to prove to the experts convened by the World Health Organization that trachoma was no longer a public health problem in Pakistan.
It took years, but it worked.
When the news was announced at the Ophthalmological Society of Pakistan, Khan says the room erupted in joy. "I can't explain the jubilation on their faces, the smile on their faces," Khan says. "Everyone was so happy. Many had tears in their eyes to see this moment in their life."
He says Pakistan now has another goal — eliminate polio — he's hoping their success with trachoma will motivate the country heading into 2025.
Copyright 2024 NPR