A new study published on Communications Medicine has revealed alarming variations in tuberculosis (TB) cases across Africa—not only between countries, but also within regions of the same country. The findings underline the urgent need for targeted interventions to control the disease effectively.

Over one million TB cases in 14 African countries
The study estimates that 1.28 million people are currently living with TB in 14 surveyed African countries. Among these, Nigeria, Mozambique, Ghana, Kenya, South Africa, and Uganda recorded the highest estimated number of cases, with Nigeria alone accounting for over 460,000. In contrast, the lowest TB burdens were found in Guinea-Bissau, Rwanda, and Mauritania.

Several other high-burden countries like Angola, the Central African Republic of Congo, the Democratic Republic of Congo, Gabon, Lesotho, Liberia, Namibia, Tanzania and Sierra Leone were also noted, although data from them were limited and outdated.

According to the authors, these findings align with the World Health Organization (WHO)’s 2021 report, which categorized all the countries mentioned as high-burden for TB.

A landmark study estimating TB cases in Africa
This research is one of the first of its kind to estimate TB prevalence at such a detailed, subnational level. It used geolocated data from 50 population-based surveys across 14 countries and applied geospatial modeling to produce maps that highlight local, subnational, and national TB trends.

“To the best of our knowledge, this is the first study to provide estimates of TB prevalence and the number of TB cases at national, subnational, and local levels in Africa,” the authors stated. “We have produced maps using geospatial modelling analysis, providing critical evidence for public health interventions and resource allocation.”

Ifakara scientist contributes to the research
Among the contributors to the study was Dr. Punam Amratia, a research scientist from the Ifakara Health Institute in Tanzania. The study team also included scientists from Ethiopia, Australia, the UK, and China.

Alemneh Mekuriaw Liyew from the Institute of Public Health, College of Medicine and Health Sciences, University of Gondar in Ethiopia is the lead author of the study.

TB prevalence varies widely within countries
The study highlights how TB prevalence can vary significantly even within the same country. Researchers emphasized that identifying high-burden areas at a local level could enhance the impact of TB prevention efforts.

“Targeting highly prevalent areas within countries not only benefits the targeted communities but also prevents the spread of TB to adjacent areas,” the authors explained.

Climatic and demographic factors as factors
Further findings show that the spatial distribution of TB in Africa is influenced by several climatic and demographic factors. For instance, warmer temperatures and higher rainfall were associated with increased TB prevalence. 

Population density was another key factor: overcrowded urban areas may increase the likelihood of TB transmission due to more frequent close contact among people. Additionally, areas with better access to cities—which often implies better access to healthcare—also showed higher TB rates, an indicator of higher detection and reporting rather than higher infection rates.

Leveraging mapping in TB response
With TB still ranked as the leading cause of death from infectious diseases globally, the authors believe this kind of detailed mapping could transform TB control across Africa. They hope the findings will guide more efficient resource distribution and ensure that interventions—such as testing, treatment, and outreach—are focused on the areas that need them most.

“The subnational and local variations in TB prevalence identified in this study suggest the importance of targeted interventions, especially in resource-limited settings,” the authors said, “These findings could be used to direct resources more efficiently towards high-risk areas,” they concluded.

Read the publication here.