A looming crisis of stroke in sub-saharan africa: few countries are prepared

Sub-Saharan Africa (SSA) is at a crossroads. The World Health Organization (WHO) has projected that by 2020 SSA will have the largest increases in noncommunicable diseases (NCDs) deaths. (1) Unfortunately SSA will also continue to suffer from the effects of Infectious Diseases (IDs). One of the NCDs is cerebrovascular disease (stroke). In this article, the epidemiology, diagnostic capacity, available treatment and patient rehabilitation in SSA settings is briefly reviewed.

Epidemiology

The incidence of stroke is unknown in many of the SSA countries. Few studies have been done to look specifically at the burden of stroke in this setting with the exception of South Africa where stroke prevalence is as high as in developed countries. (2) Most of the reports are hospital based. Prevalence of stroke between 0.26 and 300/100,000 have been reported. (2) One-year mortality after stroke in a limited number of studies from Africa has been reported up to 60%. (3) Community studies are required to establish the true burden of this important health problem.

Etiology of stroke

The causes of stroke in SSA are not well characterized. Hypertension is assumed to be the most common cause. (4) Hypertension screening is not routine and is likely to be diagnosed late. Its treatment is usually suboptimal due to many factors including drug stock outs. When patients present with stroke it may not be easy to establish the causal relationship between hypertension and stroke. Hypertension may be an acute response to stroke in up to 60% of patients. (5) Diabetes mellitus, hyperlipidemia and heart failure seem to contribute much less. (4) The role of HIV and other infections is less appreciated. In SSA younger patients presenting with stroke are more likely to be HIV positive. (6,7) CNS opportunistic infections (cryptococcal meningitis, TB meningitis, CMV) contributed 23% of all stroke cases in one study. (6) More than 80% of strokes happen in low- and middle-income countries where infections are also prevalent even without HIV risk. (8) Some patients presenting with stroke lack the traditional risk factors for stroke. Black Africans develop stroke at an earlier age compared with Whites living in the same country. (4) The role of rheumatic heart disease (RHD) and its complication has not been fully studied. More than 1 million people live with RHD and upward of 250,000 die each year of its complications. (9) There is little data on the incidence of infective endocarditis in SSA. Where infective endocarditis has been looked at, it tends to affect young adults and RHD is a common cause. (10) Infected emboli from the valves can and do cause stroke-like syndromes. Many other infections like neurocysticercosis, viral infections (herpes simplex, varicella zoster virus, CMV) have been known to cause stroke. Systemic infections have also been shown to cause stroke. (11)

At the end of 2012, almost 10 million HIV-infected individuals were on HAART, 63% of these were in SSA. (12) Short term HAART seems to ameliorate vascular dysfunction that leads to early atherosclerosis in HIV-infected individuals. (13) However, HAART has also been shown to increase the rate of vascular events. (14)

Many Africans living in cities have adopted Western dietary habits. This has resulted in increasing rates of obesity in children and adults. Obesity increased by 35% between the years of 1992 and 2005. The increase was more than 50% at the poor end of the spectrum compared with 7% at the rich end of the spectrum. (15) Increasing rates of obesity will result in increased rates of cardiovascular diseases, hypertension, type 2 diabetes mellitus and stroke. Abdominal obesity has been associated with increasing rates of stroke in all races. The risk is much higher in younger people. (16) Data on tobacco use in SSA is sparse. Data indicates that SSA is still in the early phase of a cigarette smoke epidemic. (17) This situation can quickly change if smoking control measures are not quickly adopted by governments in the region.

Diagnostic procedures

National Institute for Health and Clinical Excellence (NICE) guidelines 2008 (https://www.nice.org.uk/guidance/CG68) recommend the investigations that should be done in all patients to evaluate the type of stroke so as to help in the management of the patient presenting with stroke. While Computer Tomography (CT) scan without contrast is available in many cities in SSA, this is not true of many district and sub-district hospitals where the majority of patients present. Furthermore, even where the scans are available, radiologists and neurologists to report on the CT scan findings may not be present. As a result diagnosis is mostly clinical in nature and thus likely to overestimate the prevalence of stroke in these settings. In settings where CT scans can be done, it may not be possible to investigate for the underlying cause of the stroke.

Treatment modalities

One of the requirements for thrombolysis in patients presenting with occlusive stroke is the time interval between the beginning of symptoms and presentation at a health facility. Even in developed countries only 20-30% of patients with stroke present themselves to hospital within 4.5 hours. (18) Therefore the majority of patients even in developed countries are not eligible for thrombolysis. In many sub-Saharan Africa settings, patients are deemed to have presented early to a health facility if they do so within 24 hours of onset of symptoms. (19)

Successful management

Successful management of stroke patients is dependent on a coherent stroke management team comprising of stroke nurses, physicians, physiotherapists, occupational and speech therapists and social workers. Much of SSA is plagued with human resource for health crises. Many of the team members required for a successful stroke management are missing. In Malawi, there is 1 physiotherapist for almost half a million people. (20) Even in South Africa, considered to be much better resourced than other African countries, there are only 2 occupational therapists and 2.5 physiotherapists for every 100,000 population. In one study in rural South Africa, patients discharged from hospital were unable to continue physical therapy at home because of non-availability of rehabilitation facilities. (21) Many categories of a good stroke management team are either forgotten or not considered to be essential health service providers in SSA. The World Bank report of the year 2000 that details the human resource crisis for health in sub-Saharan Africa looked at physicians, nurses, midwives and pharmacists among the human resource required. The report is silent on the crisis affecting the rehabilitation cadres of the health work force. (22)

In conclusion

Although SSA has a looming crisis of non-communicable diseases including stroke, few countries if any are prepared to face this challenge. There is little data in the region that can be used for policy formulation. The teams required to manage stroke in its entirety are missing. There is an urgent need for well-designed studies (using standard definition for stroke) to characterize the incidence, prevalence, and type of stroke including the risk factors. Training for health providers to meet the challenge needs to start. There is need to review curriculums for doctors, nurses, physiotherapists and others to include NCDs as major challenges that the continent will soon face.

Further references on our website: www.nvtg.org and available via the author.

References

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