The Increasing Incidence of Stroke in Africa, and the Major Risk Factors

Stroke incidences have declined in high-income countries by almost 42% over the last 4 decades1 but have increased in low- and middle-income countries where 85% of global stroke deaths are reported. Incidences of stroke in Africa are among the highest globally.3-5 While stroke is uncommon in people under 40 years; when it does occur, the leading cause is hypertension.6

Stroke also occurs in about 8% of children with sickle cell disease.1

Data plotted from the SIREN study6

The SIREN (Stroke Investigative Research and Educational Network) study is, to date, the most extensive stroke risk factor study in Africa, involving 2118 stroke cases in Nigeria and Ghana.6 The study found a higher burden of stroke among Africans below age 50 years. The study also found a higher incidence of haemorrhagic stroke than ischaemic stroke; hypertension was the most important modifiable risk factor for stroke in Africa.

The stroke modifiable risk factors found in the SIREN study are consistent with the results from the INTERSTROKE study involving 26,919 stroke cases in 32 countries, including 973 stroke cases from five African countries – Mozambique, Nigeria, South Africa, Sudan, and Uganda.7  Stroke cases were patients with acute first stroke (within 5 days of symptom onset and 72 h of hospital admission).