ABSTRACT
Sub-Saharan Africa is thought to be undergoing a health (or epidemiological) and
demographic transition, moving from a pattern of disease dominated by infection,
perinatal illness and other diseases of poverty, to one dominated by noncommunicable
disease, in particular vascular disease. If such a transition is occurring,
then the burden of vascular disease including stroke will increase. Stroke is a
heterogeneous condition and it is likely that the nature of stroke (pathological types,
subtypes, and causes) will change during this transition. However, little is known
about the burden and nature of stroke in Sub-Saharan Africa, as it is now. This
information is essential to inform health services to appropriately plan and deliver
health care for the future, to develop strategies for stroke prevention, and to test the theory of the health and demographic transition.
My overall aim was to assess and compare the burden and nature of stroke in rural
and urban South Africa, and to establish whether there is any evidence of a health
transition. Specifically I aimed to:
• review what is known about stroke in Sub-Saharan Africa;
• establish the prevalence and nature of prevalent stroke in rural South Africa;
• compare the nature of hospital-based stroke in urban and rural stroke patients;
• compare the nature of urban hospital-based stroke in different population
groups; and • validate two stroke scores in the urban stroke register to enable us to diagnose
pathological stroke type in rural stroke patients who do not have access to
brain imaging.
Methods: The following methods were used to achieve these aims:
• I systematically searched the literature for, and critically reviewed, studies of
stroke from Sub-Saharan Africa (literature review).
• The rural Agincourt Health and Population Unit demographic surveillance site
was screened for stroke using two questions during the annual census.
Anyone who screened positive for stroke was examined to decide whether
they had had a stroke (stroke prevalence study).
• The Tintswalo Hospital Stroke Register was established to ascertain and
assess rural stroke patients over 20 months (rural hospital-based stroke), and
• The Johannesburg Hospital Stroke Register similarly established to assess
urban stroke patients over 23 months (urban hospital-based stroke).
• The accuracy of the Siriraj and Guy’s Hospital stroke scores was compared to
the CT brain scan “gold-standard” in the Johannesburg Hospital Stroke Register. Results: Using these approaches I found that:
• Very little is currently known about the burden and nature of stroke in Sub-
Saharan Africa.
• The prevalence of rural stroke was about half that found in high-income
countries, and double that found in Tanzania. However, disabling stroke was at
least as prevalent as it is in high-income countries.
• Both rural and urban black South Africans are probably in early phases of the
health transition, and this is impacting on the nature of stroke, particularly the
cause of cardioembolic stroke.
• Neither the Siriraj nor Guy’s Hospital stroke score are sufficiently accurate for
use in epidemiological studies or clinical management of stroke in Sub-
Saharan Africa.
Conclusion: There is already a heavy burden of stroke in Sub-Saharan Africa, and
there is some evidence of a health transition in the black population. However, it is
not possible to accurately assess the burden and nature of stroke without communitybased
incidence studies using early brain imaging to distinguish ischaemic stroke
from cerebral haemorrhage. Until we have these studies, we will never know the
precise burden and nature of stroke, the effect of the health transition, or the optimal
approach to preventing a stroke epidemic in our population.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/5030 |
| Date | 11 July 2008 |
| Creators | Connor, Myles Dean |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 4479358 bytes, application/pdf, application/pdf |
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