Around 10 million people contract and more than one million die from tuberculosis each year, mostly in countries far away from the affluent West. But yesterday’s World Tuberculosis Day is a reminder that this curative disease is a global problem – one that is only getting worse. Covid-19 pandemic disease shows that infectious diseases do not respect borders, and TB remains a stagnant feature of Western cities, not just developing countries. With 150 cases per 100,000 people, parts of London recently had higher levels of TB than Iraq or Rwanda, rates in areas of New York City such as Sunset Park or West Queens in 2019 were six times higher than national average, and French experts last year once again worried about “hot spots” in northern Paris.
Three things contribute to this problem. Before it becomes active and contagious, usually invading the lungs, TB can remain dormant for years. Experts estimate that about one in four living people today – around two billion – carry latent TB and about 10 percent of them develop active TB over a lifetime. That means that the 10 million people who develop active TB each year represent just the tip of the iceberg. Many people around the world are surviving active TB – and it is plagued with hidden TB cases constantly escalating into infectious cases.
The second problem is that Covid-19 made us take our eye off the ball. As the world has focused on testing for and detecting the pathogen SARS-CoV-2, testing for and detecting falling TB. Deaths from this bacterial infection had fallen from 1.7 million in 2000 to 1.2 million in 2019. But our recent attention means that TB numbers are expected to rise again. The Stop TB partnership of government and non-governmental organizations estimates that we could easily have an additional 1.4 million deaths and 6.3 million active cases over the next five years. It is safe to assume that the number of additional hidden TB cases is much higher.
Third, we have to contend with this expanded reservoir of latent TB just as the world goes up again after various waves of Covid-19-induced locking. People all over the world travel again and gather to explore, do business or enjoy being together again. As the world begins to contract again, millions of people will develop active TB after months or years of carrying the unidentified latent disease in their bodies. Their symptoms can be mild and go unnoticed and untreated for months. The World Health Organization (WHO) estimates that such victims can take another 10–15 people over a year.
The combination of these factors means that 1500 groups of the Stop TB partnership fear that the fight against TB could be delayed by five to eight years. WHO governments want to cut annual TB deaths by 90 per cent from 2015 levels and new annual cases by 80 per cent by 2035 – by screening for latent TB and preventing cases from becoming active, by testing for and handling active issues and finding connections. If Stop TB warnings prove to be correct, its strong actions over the last few years have not been revealed.
Fortunately, the commendable work of the WHO, Stop TB and their partners, which operate under the auspices of the United Nations, means that this worst case scenario is not a difficult decision. The world can double its anti-TB measures to identify and treat people with TB and quickly reduce the pool of recently undiagnosed cases. That would require a strong return to screening for and handling covert cases, as well as a ramped test for operational cases along with community engagement and contact detection. That means we need to make sure that as many people with hidden and active TB as possible have access to the right treatment as soon as possible.
Ironically, we have two legacies of our response to Covid-19 that should give us hope for TB. Many health systems have now tested and discovered unprecedented infrastructures that we can use to test for TB. Similarly, ordinary people around the world in the past year have come to understand, support and even get tested for disease. This “proof-of-concept” approach allows governments to create a unique movement for covert TB screening campaigns. TB is one of the oldest infectious diseases found in the ancient bodies of Egyptian pharaohs. It has been a human habit for thousands of years. We still have a chance to finally gain control.
Photo: ThitareeSarmkasat, Getty Images