SummaryA high prevalence of epilepsy is reported in many onchocerciasis‐endemic regions. In this paper we discuss recent epidemiological and clinical aspects as well as public health implications of onchocerciasis‐associated epilepsy (OAE) and propose a strategy to reduce the burden of disease. OAE probably presents in a variety of clinical manifestations, including the nodding syndrome and the Nakalanga syndrome. The most common clinical presentation, however, is generalized (primarily tonic‐clonic) seizures. A characteristic of OAE is the onset of seizures between the ages of 3 and 18 years and clustering in certain families and villages close to rapid‐flowing black‐fly‐infested rivers. A strategy combining active surveillance for epilepsy with early treatment with antiepileptic drugs and prevention of onchocerciasis by increasing the geographical and therapeutic coverage of community‐directed treatment with ivermectin (CDTi) may considerably decrease the burden of disease.

BackgroundA high prevalence of epilepsy has been observed in many onchocerciasis endemic regions. This study is to estimate the prevalence of active epilepsy and exposure to Onchocerca volvulus infection in a rural population in Ituri province, Democratic Republic of Congo.MethodsIn August 2016, a community-based cross-sectional study was conducted in an onchocerciasis endemic area in the rural health zone of Logo, Ituri Province. Households within two neighbouring health areas were randomly sampled. To identify persons with epilepsy, a three-stage approach was used. In the first stage, all individuals of the selected households were screened for epilepsy by non-medical field workers using a validated 5-item questionnaire. In the second and third stage, suspected cases of epilepsy were examined by non-specialist medical doctors, and by a neurologist, respectively. A case of epilepsy was defined according to the 2014 International League Against Epilepsy (ILAE) guidelines. Exposure to O. volvulus was assessed by testing for IgG4 antibodies to an O. volvulus antigen (OV16 Rapid Test,) in individuals aged 3 years and older.ResultsOut of 1389 participants included in the survey, 64 were considered to have active epilepsy (prevalence 4.6%) (95% confidence interval [CI]: 3.6–5.8). The highest age-specific epilepsy prevalence estimate was observed in those aged 20 to 29 years (8.2%). Median age of epilepsy onset was 10 years, with a peak incidence of epilepsy in the 10 to 15 year-old age group. OV16 test results were available for 912 participants, of whom 30.5% (95% CI, 27.6–33.6) tested positive. The prevalence of OV16 positivity in a village ranged from 8.6 to 68.0%. After adjusting for age, gender and ivermectin use, a significant association between exposure to onchocerciasis and epilepsy was observed (adjusted odds ratio = 3.19, 95% CI: 1.63–5.64) (P < 0.001).ConclusionsA high prevalence of epilepsy and a significant association between epilepsy and exposure to O. volvulus were observed in the population in Ituri province, Democratic Republic of Congo. There is an urgent need to implement a CDTI programme and to scale up an epilepsy treatment and care programme.Electronic supplementary materialThe online version of this article (10.1186/s40249-018-0452-1) contains supplementary material, which is available to authorized users.

Abstract.There is little published information on the epidemiology of neurological disorders in rural Central Africa, although the burden is considered to be substantial. This study aimed to investigate the pattern, etiology, and outcome of neurological disorders in children > 5 years and adults admitted to the rural hospital of Mosango, province of Kwilu, Democratic Republic of Congo, with a focus on severe and treatable infections of the central nervous system (CNS). From September 2012 to January 2015, 351 consecutive patients hospitalized for recent and/or ongoing neurological disorder were prospectively evaluated by a neurologist, subjected to a set of reference diagnostic tests in blood or cerebrospinal fluid, and followed-up for 3–6 months after discharge. No neuroimaging was available. Severe headache (199, 56.7%), gait/walking disorders (97, 27.6%), epileptic seizure (87, 24.8%), and focal neurological deficit (86, 24.5%) were the predominant presentations, often in combination. Infections of the CNS were documented in 63 (17.9%) patients and mainly included bacterial meningitis and unspecified meningoencephalitis (33, 9.4%), second-stage human African trypanosomiasis (10, 2.8%), and human immunodeficiency virus (HIV)-related neurological disorders (10, 2.8%). Other focal/systemic infections with neurological manifestations were diagnosed in an additional 60 (17.1%) cases. The leading noncommunicable conditions were epilepsy (61, 17.3%), psychiatric disorders (56, 16.0%), and cerebrovascular accident (23, 6.6%). Overall fatality rate was 8.2% (29/351), but up to 23.8% for CNS infections. Sequelae were observed in 76 (21.6%) patients. Clinical presentations and etiologies of neurological disorders were very diverse in this rural Central African setting and caused considerable mortality and morbidity.

HighlightsA high epilepsy prevalence in the Aketi health zone was observed despite 14 years of community-directed treatment with ivermectin.The high prevalence of OV16 antibodies in children is indicative of high ongoing onchocerciasis transmission.High onchocerciasis transmission is the consequence of high exposure to blackflies and low intake of ivermectin.Head nodding seizures were observed in 13.8% of the persons with epilepsy.Ivermectin coverage needs to be increased and bi-annual distribution should be considered.