Did you know around 10 million people developed tuberculosis (TB) in 2019? That number alone is scary, but what is even more alarming is TB is the leading cause of death by an infectious disease globally, causing 1.4 million deaths last year!
What is the main issue?
There are several factors that cause high rates of TB disease and deaths, but failure to diagnose those living with TV and provide them with the correct treatment contributes largely to the spread of TB and rising deaths. World Health Organization is working on amending its TB guidelines to include recommendations for TB screening using TB x-rays, along with computer-aided detection (CAD) software.
A bit of hope…
CAD software developed recently makes use of artificial intelligence (AI) in the form of deep learning networks to identify lung abnormalities that are suggestive of TB. This tool can be used to improve TB screening a great deal. Dr Richard Tuft, Executive Director of the Radiological Society of South Africa has stated that AI will play a crucial role in interpreting medical images like x-rays both in South Africa and worldwide. The reason AI is being used is because there is a dire shortage of radiologists in the country, as hundreds of TB x-rays taken in South Africa are never interpreted. However, radiologists have to keep validating technologies and and taking professional responsibility for the diagnostic reports.
Why are TB x-rays important?
When it comes to detecting TB, x-ray screening is more effective as compared to the traditionally used four-symptom screen that includes cough, fever, weight loss, and night sweats. In fact, data presented by Dr Lindiwe Mvusi, Director of TB Control in the National Department of Health, at the Union World Conference on Lung Health in October 2020, suggest that rates of undiagnosed TB in South Africa could be higher than previously understood.
Dr. Mvusi reported that as per South Africa’s first national TB prevalence survey more than half of the TB cases identified in the survey had an abnormal lung X-ray only without reporting any of the four symptoms used to screen for TB. That is why the diagnostic algorithm has to be revised to include TB chest x-rays.
What is the next step?
A major hiccup to the above mentioned approach is the limited access to x-ray machines. Lightweight and portable x-ray machines are now available in the market. They can be used to assist health workers in reading and interpreting X-rays in decentralized health settings. It is truly a blessing in disguise, especially in rural areas where access to a hospital and other healthcare facilities can be expensive and time-consuming.
But South Africa, like many countries doesn’t have the regulatory pathways to authorize use of these ultra-portable devices. As per current regulatory guidelines X-ray devices can’t be moved around and need to be fixed in a room of a certain size. That is why WHO has to step in and evaluate these devices for pre-qualification. But it is a long process and will definitely take a while!