Epidemiological, clinical and radiological characteristics of people with neurocysticercosis in Tanzania–A cross-sectional study

Abstract

Background Neurocysticercosis (NCC) is common among people with epilepsy in low-resource settings. Prevalence of NCC and radiological characteristics of patients with NCC vary considerably even within small areas but differences have been poorly characterized so far. Methods We conducted a cross-sectional study between August 2018 and April 2020 in three district hospitals in southern Tanzania (Ifisi, Tukuyu and Vwawa). Patients with and without epileptic seizures were included in this study. All patients were tested with a novel antibody-detecting point-of-care test for the diagnosis of Taenia solium cysticercosis. All test positives and a subset of test negatives had a further clinical work-up including medical examination and computed tomography of the brain. NCC was defined according to the Del Brutto criteria. We assessed epidemiological, clinical and radiological characteristics of patients with NCC by presence of epileptic seizures and by serology status. Results In all three district hospitals, more than 30% of all people with epileptic seizures (PWE) had NCC lesions in their brain (38% in Vwawa, 32% in Tukuyu and 31% in Ifisi). Most PWE with NCC had multiple lesions and mostly parenchymal lesions (at least 85%). If patients were serologically positive, they had in the median more lesions than serologically negative patients (15 [interquartile range 8–29] versus 5 [1.8–11]), and only serologically positive patients had active stage lesions. Furthermore, serologically positive PWE had more lesions than serologically positive people without epileptic seizures (10.5 [7–23]), and more often had active lesions. PWE diagnosed with NCC (n = 53) were older, and more commonly had focal onset seizures (68% versus 44%, p = 0.03) and headache episodes (34% versus 14%, p = 0.06), which were also stronger than in PWE without NCC (p = 0.04). Conclusion NCC is common among PWE. A combination of clinical and serological factors could help to establish an algorithm to identify patients potentially suffering from active NCC, who benefit from further clinical investigation including neuroimaging. Author summary Neurocysticercosis (NCC) is a neglected tropical disease caused by the pork tapeworm Taenia solium. The disease remains often silent for years, and some patients never experience any symptoms at all. If the disease becomes symptomatic, symptoms are manifold but most commonly patients suffer from epileptic seizures or headache. Symptoms depend on the location, number and stage of the NCC lesions. Radiological features of NCC differ between world regions and are still understudied for African populations. In this study, we describe radiological but also clinical features of NCC patients with and without epileptic seizures. We found that around one third of patients with epileptic seizures had NCC typical lesions in their brain. Most patients had multiple parenchymal lesions–patients with epileptic seizures had on average more lesions than asymptomatic patients. Patients with epileptic seizures and NCC more commonly had focal onset seizure than patients with epileptic seizures without NCC.