The Rising Tide of Stroke in Tanzania: An Urgent Call for Action

The burden of stroke is rising in low- and middle-income countries (LMIC), particularly in sub-Saharan Africa (SSA). Contrary to high-income countries (HIC), which have reported a decline in age-standardized stroke incidence, disability-adjusted life years (DALYs) and mortality, LMICs have the highest age-standardized stroke-related mortality of more than 3.6 times. This high stroke burden is linked to the fact that African countries, including Tanzania, are currently undergoing an upsurge in non-communicable diseases (NCD), particularly cardiovascular diseases mainly linked to epidemiological transitioning. Furthermore, the improved life expectancy in SSA as a result of early diagnosis, treatment and control of HIV/AIDS and other infectious diseases has led to an increased prevalence of stroke and other NCDs. In Tanzania, life expectancy has improved from 49 years in 1995 to 66 years in 2022.


Hypertension is the leading risk factor for stroke in Tanzania, and its early detection, treatment and management cannot be overemphasized. Previous studies in SSA have demonstrated that 45% of all strokes could be prevented by simply measuring and controlling blood pressure. It is notable that in Tanzania, stroke occurs at a much younger age with later presentation associated with devastating outcomes. Hospital-based studies have reported early mortality ranging from 30-60%. This figure is alarming as approximately 50% of the Tanzanian population comprises individuals between 15 to 54 years who are the nation’s task force. There is an urgent need for promoting research to identify the possible etiologies and drivers of hypertension among young Tanzanians. Of note, ischemic stroke sub-type occurs at a higher proportion than hemorrhagic stroke in Tanzania. A recent study conducted at a large academic hospital reported 11.3% of all medical admissions being ischemic strokes, of which 39.2% had presumed large vessel occlusion with a one-year mortality of 80%. These findings are of particular importance given the lack of previous sound data on the burden of large vessel ischemic stroke in SSA and the potential for introducing acute interventional therapies for the management of acute ischemic stroke into the local neurological landscape. In particular, endovascular interventions for stroke require highly trained personnel who are proficient in the use of advanced imaging techniques to guide interventional procedures promptly. These therapeutic options have proven to be effective in improving acute stroke outcomes in HICs, such as morbidity and mortality from stroke. However, several barriers need to be overcome before establishing these interventions, including lack of community awareness regarding stroke symptoms and signs, the delayed presentations of patients, shortage of specialized stroke units, high costs of medical procedures, and scarce human resources necessary for the management of acute stroke. Currently, there is only one private center offering intravenous thrombolysis for treating acute ischemic stroke in Tanzania. Furthermore, standard guidelines for managing stroke patients are lacking in most hospitals in Tanzania since stroke is given less priority by funding agencies, and there are very few centers that offer rehabilitation services to stroke patients in SSA. This has an overall impact on disease prognosis as stroke affects health-related quality of life in different domains related to cognition, physical, psychological and socioeconomic aspects.


Moving forward, stroke is preventable in Tanzania – but it requires a holistic approach involving key stakeholders necessary for diverting the available resources channeled for infectious diseases to NCDs at various stages of stroke prevention. For primary prevention, we need to strongly advocate for early detection, treatment and control of modifiable risk factors and promote health education to the public. In terms of secondary prevention, a call for advocating endovascular therapies necessary for reducing morbidity and mortality from stroke is much needed. While our call is vast and ambitious, the stakes are high for patients in Tanzania and all across SSA struggling through a debilitating ailment.


References

1. Feigin VL, Stark BA, Johnson CO, Roth GA, Bisignano C, Abady GG, et al. Global, regional, and national burden of stroke and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019. Lancet Neurol. 2021;20(10):795–820.

2. Owolabi MO, Akarolo-Anthony S, Akinyemi R, Arnett D, Gebregziabher M, Jenkins C, et al. The burden of stroke in Africa: a glance at the present and a glimpse into the future. Cardiovasc J Afr. 2015;26(21):S27-38.

3. United Nations. Department of Economics and Social Affairs. World Population Prospect | Multimedia Library - United Nations Department of Economic and Social Affairs [Internet]. 2017 [cited 2019 Oct 29]. p. Key FindingWorking Paper No. ESA/P/WP/248. Available from: https://www.un.org/development/desa/publications/world-population-prospects-the-2017-revision.html

4. United Nations- World Population Prospects. Tanzania Life Expectancy 1950-2022 | MacroTrends [Internet]. [cited 2022 Sep 7]. Available from: https://www.macrotrends.net/countries/TZA/tanzania/life-expectancy

5. Walker RW, Jusabani A, Aris E, Gray WK, Unwin N, Swai M, et al. Stroke risk factors in an incident population in urban and rural Tanzania: A prospective, community-based, case-control study. Lancet Glob Health. 2013;1(5):282–8.

6. Cruickshank JK, Mbanya JC, Wilks R, Balkau B, Forrester T, Anderson SG, et al. Hypertension in four African-origin populations: current ‘Rule of Halves’’, quality of blood pressure control and attributable risk of cardiovascular disease.’ J Hypertens. 2001 Jan;19(1):41–6.

7. Okeng’o K, Chillo P, Gray WK, Walker R, Matuja W. Early Mortality and Associated Factors among Patients with Stroke Admitted to a Large Teaching Hospital in Tanzania. Journal of Stroke and Cerebrovascular Diseases. 2017;26(4):871–8.

8. Matuja S, Munseri P, Khanbhai K. The burden and outcomes of stroke in young adults at a tertiary hospital in Tanzania : a comparison with older adults. BMC Neurol. 2020;20(1):206.

9. Matuja SS, Ahmed RA, Munseri P, Khanbhai K, Tessua K, Lyimo F, et al. Ischemic Stroke at a Tertiary Academic Hospital in Tanzania: A Prospective Cohort Study With a Focus on Presumed Large Vessel Occlusion. Front Neurol [Internet]. 2022 [cited 2022 Sep 7];13(July):1–9. Available from: https://pubmed.ncbi.nlm.nih.gov/35911912/

10. Aronsson M, Persson J, Blomstrand C, Wester P, Levin LA. Cost-effectiveness of endovascular thrombectomy in patients with acute ischemic stroke. Neurology. 2016 Mar 15;86(11):1053–9.


 

Dr. Sarah Matuja, MD, MMed, MSc Fellow is a Senior Lecturer in the Department of Internal Medicine at the Catholic University of Health and Allied Sciences-Weill Bugando in Tanzania. Her interests are in neurology, particularly in improving stroke care and clinical outcomes. She is a current fellow for both The World Stroke Organization Future Leaders Program (Cohort-2) and the Training Africans to Lead and Execute Neurological Trials Program (Cohort-1), and a former NIH-NINDS Global Health Fogarty Fellow. Her ultimate goal is to conduct collaborative clinical research in Tanzania, sub-Saharan Africa and globally that will improve the health of the population.