More people die from tuberculosis than from any other infectious disease globally, with an estimated 1.2 million deaths attributed to it in 2025. In Africa, people diagnosed with tuberculosis accounted for around a quarter of the world’s cases, resulting in approximately 315,000 deaths in 2024.1
Historically, tuberculosis has been considered a disease of younger people. However, as people live longer older adults are increasingly living with multiple chronic diseases, such as diabetes and heart disease, which can increase the risk of the disease.
The impact of increased life expectancy on the average age of tuberculosis diagnosis in Southern African countries, where tuberculosis remains common, is poorly understood, with no published studies examining this association.
Researchers from Bristol Medical School based at The Health Research Unit in Zimbabwe wanted to find out if tuberculosis is affecting more older people now than it used to. They investigated how the average age of people receiving a tuberculosis diagnosis changed over the last 25 years in Zimbabwe. This work was supported by the Elizabeth Blackwell Institute for Health Research at the University of Bristol, the UK National Institute for Health and Care Research (NIHR), and Wellcome.
The team analysed results from 12 separate studies using data from 15,925 people who had been diagnosed with tuberculosis between 2000 and 2024. Researchers used this data to model how age at diagnosis with tuberculosis changed over time.
Their results showed that the average age at diagnosis of tuberculosis increased from 33.9 years for males and 28.9 years for females in 2000 to 41.3 years for males and 40.4 years for females in 2024. These results show that people with tuberculosis are, on average, older now than they were in 2000, particularly women. Because older adults experience tuberculosis differently, with different symptoms and more side effects to the treatment used, this is an important finding.
Professor Celia Gregson, NIHR Global Health Research Professor of Healthy Ageing in Africa, and co-director of The Health Research Unit Zimbabwe, said: “These important data show tuberculosis is increasingly a disease associated with ageing, the management of these older patients will be more complex because of other age-associated diseases, such as diabetes and kidney disease, and conditions such as frailty and sarcopenia, which need to be managed alongside standard tuberculosis treatment.
“Given our results, global and local strategies for diagnosing and treating tuberculosis need to consider the specific needs of older adults. These results also highlight the need for the annual reporting of tuberculosis data, which is done by the World Health Organization, to provide greater detail on the age of people diagnosed with tuberculosis to make further monitoring of changes in age at diagnosis simpler.”
The researchers emphasise that research should replicate this analysis in other African countries where tuberculosis is common to determine whether they are experiencing the same ageing trends that we have shown here in Zimbabwe. Furthermore, guidelines will need to be updated to take account of age-associated factors when managing tuberculosis.
Paper
'Temporal changes in age at diagnosis with tuberculosis in high-HIV prevalence settings: a pooled multi-cohort analysis from Zimbabwe' by Stanley JL, Marambire E, Calderwood C, Gregson CL, de Wilton A, Kavenga F et al. in The Lancet Regional Health – Africa.