Lifetime prevalence of epilepsy in urban Tanzania - A door-to-door random cluster survey

Objectives: Epileptic seizures and epilepsy in urban settings of low-income and middle-income countries (LMIC) are largely under-researched, but their prevalence is necessary for good healthcare planning. This study aimed to determine the lifetime prevalence of epileptic seizures and epilepsy in urban Dar es Salaam.

Methods: Nearly 50,000 people in former Kinondoni district, Dar es Salaam, were screened for epileptic seizures using a set of nine questions. Answers to these nine questions were categorized into generalized, focal, and unspecified seizures. Screening positivity rates were adjusted for questionnaire inaccuracy using two scenarios to analyse true epilepsy prevalences.

Results: Overall, 1085 (2.23%) people fulfilled the criteria for ever having had at least one type of epileptic seizure. Two-hundred-ninety-six (0.60%) people screened positive for generalized seizures, 986 (2.02%) for focal seizures, and 32 (0.07%) for unspecified seizures. Women more commonly screened positive than men (2.61% versus 1.72%, p < 0.001), particularly for focal seizures (p < 0.001). Adjusting for different degrees of accuracy of the screening questionnaire yielded true lifetime prevalences for epilepsy of any type between 1.59% and 2.41%. We furthermore observed a considerable variation of screening positivity rates between wards in Kinondoni district (p < 0.001).

Conclusion: The prevalence of epilepsy, based on a questionnaire survey in urban Tanzania, was higher than previously observed, probably due to the screening questionnaire, which contained questions specifically designed to identify focal seizures. Further studies on epileptic seizures/epilepsy are needed for urban settings in LMIC, preferably with an integrated follow-up of positive cases.