AI steps in to detect the world's deadliest infectious disease

One morning last month, the Boniaba Community Health Center in Mali was running a TB screening. There was no doctor in sight. Yet, a mother plagued by coughing got an answer in a matter of seconds: She was positive for TB.

A few years ago, she'd have been lucky if there was a screening nearby. And still, she'd have had to wait a week or two for a sputum test to be sent to a lab and results to come back. The difference? A mobile x-ray machine and an AI algorithm are detecting TB.

TB is the world's top infectious disease killer — with 3,500 people dying of it each day for an annual total of more than 1.2 million deaths. And the numbers are going up. One of the hurdles in tackling the epidemic has been a global shortage of radiologists to diagnose this bacterial infection that usually affects the lungs. "There are countries in which there are less than five radiologists. It's like a disaster. And, even if you have some, they will always be in the capitals," says Dr. Lucica Ditiu, the executive director of the Stop TB Partnership. Now, she says, over 80 low- and middle-income countries are turning to AI to screen people for TB.

For example, nomadic population in Nigeria is benefiting. "You're in the middle of nowhere. There are these guys. There's cattle. There is dust and nothing else. And they are doing these x-rays with AI. It's unreal," says Ditiu, whose organization was among the pioneers in developing this technology eight years ago.

The AI models are also being used in refugee camps in Chad. "There are no radiologists. So who gets to look at the [x-ray] and say: 'Is there a problem here or not?' Well, actually, AI does," say Peter Sands, the executive director of the Global Fund to Fight AIDS, TB and Malaria, which has invested close to $200 million into AI-enabled TB screenings in the past four years. "It's brilliant."

At the Boniaba Community Health Center, the mother is one of dozens of people who get an x-ray from a mobile x-ray machine that Diakité Lancine has set up. He's not a doctor but has been trained to take x-rays. The image he snaps is sent directly to his computer, where the AI model reads it and spits out a score based on how much AI thinks the image looks like TB and a picture of the person's lungs that looks almost like a heat map.

As soon as the mother's screening comes back with several red patches, he collects a sputum sample to send to the lab for confirmation. Then he tells her to go home quickly and bring her five kids back so he can check them too. TB spreads through the air when someone with active TB coughs, laughs or talks and can be transmitted readily in households.

Almost instantly, AI tells them: Three of her kids appear to have TB. Soon, Lacine says, they'll started on a six month course of antibiotics to treat the TB.