The impact of the epidemiological transition in low- and middle-income countries

Double burden

Low- and middle-income countries (LMICs) are undergoing a rapid epidemiological transition. On the one hand, mortality caused by infectious diseases is declining. On the other hand, there is a steep rise in noncommunicable diseases (NCDs), which are now the main cause of mortality in all countries in the world.  [1] In most LMICs in the last decades, overall mortality declined because of vaccination programmes, mother- and-child health care, improvements in water supply, sanitation and basic curative care. However, in the last decades, LMICs are seeing large increases in cardiovascular disease, diabetes, cancers, and chronic respiratory disease. 

In high‑income countries, the transition was a matter of generations. In LMICs, the changes are occurring over decades, making the epidemiological transition more disruptive for health systems. 

LMICs face a persistent double burden of disease, where HIV, TB, malaria, neglected tropical diseases, respiratory and diarrhoeal infections, and undernutrition require much attention while NCDs accelerate.  This leads to high levels of multimorbidity, including coexisting infectious and chronic conditions (for example, HIV plus hypertension or diabetes), which increases service use, hospitalisations, and financial hardship where out‑of‑pocket payments are high. [2] 

In general, Asian countries are in further stages of the transition with lower mortality due to infectious diseases, while many African countries remain strongly affected by HIV, TB, and other infections. Even within countries, urban centres often have higher NCD and lower mortality due to infectious disease than rural areas. [3]

Key drivers

Reduction of infant and child mortality, combined with reduction of mortality due to infectious diseases, leads to demographic change with increasing life expectancy, leading to more adults vulnerable to chronic diseases. The globalisation of unhealthy diets, tobacco, alcohol and substance abuse are central to rising NCD burdens in LMICs. [4] In addition, rapid urbanisation leads to changes in composition of the population. Older adults in LMICs, for instance India, are encountering issues such as diminishing familial and societal roles due to urbanisation, youth migration, a shift from joint to nuclear family structures, greater workforce participation by women, increasing economic disparity and stark healthcare inequalities. [5]

Health inequities are prominent in NCDs. In the lowest social economic strata (SES) in LMICs, the prevalence of infectious diseases is still high, due to unhealthy living conditions. People in the lowest SES are also confronted earlier with chronic diseases and live longer in unhealthy conditions. [4]

Implications for health systems and policy

Health systems in LMICs operate around vertical, infection‑focused programmes and acute episodic care. They have no systems in place for chronic, multimorbid patients requiring long‑term, integrated, person‑centred care. Primary healthcare in particular is not ready for diagnosis and treatment of NCDs.[6] Policy responses increasingly emphasise integrated management of infectious diseases and NCDs (for example, incorporating hypertension and diabetes screening into HIV or TB services), alongside broader strategies on tobacco control, healthy diets, physical activity, and air pollution. 

Global response

The United Nations plays a big role in global policy development for the reduction of NCDs worldwide, in particular the WHO. Four high-level meetings were conducted over the last fifteen years, setting the agenda for prevention and treatment of NCDs. The latest high-level meeting, in September 2025, set the following priorities: improving tobacco and nicotine control, preventing and scaling up effective treatment of cardiovascular risk factors such as hypertension, and improving mental health care. This should result in 150 million fewer people using tobacco, 150 million more people having hypertension under control, and 150 million more people with access to mental health care. [7]

In 2020, the WHO launched the “Decade of Healthy Ageing” promoting physical, cognitive, and social well-being throughout an individual’s life. The concept of healthy ageing is gaining prominence due to a constant increase in the older adult population across the world, with profound implications for economies, societies and family relations, public policy, labour markets and, most notably, healthcare systems. [8] Via this platform for healthy ageing, experiences can be shared globally.

Conclusion

NCDs will dominate the global burden of diseases in the coming decades, despite possible new pandemics. Social determinants of health are important drivers for the increase of NCDs. Prevention must become a priority in all countries, and health systems must adapt to the changing disease patterns and provide early diagnosis and treatment. To which the integration of vertical programmes and incorporation of mental healthcare is a priority.

Sources

[1] Shu, J., Jin, W. Prioritizing non-communicable diseases in the post-pandemic era based on a comprehensive analysis of the GBD 2019 from 1990 to 2019. Sci Rep 13, 13325 (2023). https://doi.org/10.1038/s41598-023-40595-7

[2] Basto-Abreu A, Barrientos-Gutierrez T, Wade AN, et al. Multimorbidity matters in low and middle-income countries. J Multimorb Comorb. 2022;12:26335565221106074. Published 2022 Jun 16. doi:10.1177/26335565221106074 [3] Multimorbidity matters in low and middle-income countries – PMC https://pmc.ncbi.nlm.nih.gov/articles/PMC9208045/

[3] Ndubuisi NE. Noncommunicable Diseases Prevention In Low- and Middle-Income Countries: An Overview of Health in All Policies (HiAP). Inquiry. 2021;58:46958020927885. doi:10.1177/0046958020927885

[4] Gulis, G., Zidkova, R. & Meier, Z. Changes in disease burden and epidemiological transitions. Sci Rep 15, 8961 (2025). https://doi.org/10.1038/s41598-025-94050-w

[5] Sadana, Ritu & Michel, jean-pierre. (2019). Healthy Ageing: What Is It and How to Describe It?. 10.1007/978-3-319-96529-1_2.

[6] Kabir A, Karim MN, Islam RM, et al. Health system readiness for non-communicable diseases at the primary care level: a systematic review. BMJ Open2022;12:e060387. doi:10.1136/bmjopen-2021-060387

[7] WHO: political declaration of high level meeting on NCDs : https://www.who.int/publications/m/item/rev.4–political-declaration-of-the-fourth-high-level-meeting-of-the-general-assembly-on-theprevention-and-control-of-noncommunicable-diseases-and-the-promotion-of-mental-healthand-well-being

[8] WHO decade of healthy ageing. https://www.who.int/initiatives/decade-of-healthy-ageing

Affiliations: ¹ Group Leader, Heidelberg Institute for Global Health, Heidelberg University; ² Assistant Professor, Kazi Nazrul Islam Mahavidyalaya; ³ Professor, Department of Developmental Biology and Genetics, Indian Institute of Science

Corresponding author: Dr. Suboor Bakht bakht@hcsa.uni-heidelberg.de