The onchocerciasis hypothesis of nodding syndrome

Enigmatic intractable Epilepsy patients have antibodies that bind glutamate receptor peptides, kill neurons, damage the brain, and cause Generalized Tonic Clonic Seizures

Epilepsy affects 1-2% of the world population, is enigmatic in 30% of cases, and is often intractable, unresponsive to antiepileptic drugs, and accompanied by cognitive, psychiatric and behavioral problems. Tests for Autoimmune Epilepsy are not performed routinely, and limited to passive diagnosis of known autoimmune antibodies, without essential functional tests to reveal active pathogenic antibodies. We investigated two young Epilepsy patients with different Epilepsy characteristics, repeated intractable seizures, and enigmatic etiology. We suspected Autoimmune Epilepsy. We found that both patients have elevated IgG antibodies, and three types of glutamate receptor antibodies, to: AMPA-GluR3B, NMDA-NR1 and NMDA-NR2 peptides. In contrast, they lack autoantibodies to: LGI1, CASPR2, GABA-RB1, Amphiphysin, CV2, PNMA1, Ri, Yo, Hu, Recoverin, Soxi and Titin. IgG antibodies of both patients bound and killed human neural cells In vitro. Moreover, In vivo video EEG studies in naive rats revealed that patient's IgG antibodies, infused continually into rat brain, bound neural cells in the hippocampus and cortex, caused neural loss in these brain regions, and induced recurrent Generalized Tonic Clonic Seizures. We assume they can do so also in the patient's brain. This is the first model of human Autoimmune Epilepsy in rats. It can serve for discovery of patient's pathogenic antibodies, and drug development. Tests for autoimmune antibodies that bind glutamate receptor peptides, and functional diagnostic tests, are obligatory in all enigmatic intractable Epilepsy patients. Current diagnosis of Autoimmune Epilepsy is insufficient! If pathogenic antibodies are found, intractable patients must receive available, suitable and potentially life-changing immunotherapies for Autoimmune Epilepsy.

Delayed correct diagnoses in emerging disease outbreaks: historical patterns and lessons for contemporary responses

BACKGROUND

The gap between early diagnostic assumptions and final diagnoses in disease outbreaks represents a persistent challenge in global health despite advancements in diagnostic and response capabilities.

OBJECTIVES

To analyse the unfolding 2025 outbreak in the Democratic Republic of Congo (DRC) through the lens of historical cases where initial misattributions contributed to delayed recognition of novel or unexpected threats with varying public health consequences; identifying patterns from past outbreaks that can inform current diagnostic approaches and response strategies.

SOURCES

We selected illustrative examples from peer-reviewed publications, focusing on cases with initial diagnostic uncertainties that highlight specific diagnostic patterns relevant to the current DRC outbreak. For the ongoing DRC outbreak, we analysed official World Health Organization Africa bulletins and communications from the DRC Ministry of Health through February and early March 2025.

CONTENT

As of beginning of April 2025, health authorities continue investigating clusters of unexplained acute febrile illness in Équateur Province with clinical features that were initially being suggestive of a viral haemorrhagic fever. Primary viral haemorrhagic fever pathogens have now been excluded. From selected historical and recent outbreaks, it can be deduced that diagnostic challenges extend beyond individual cognition to include structural biases in global health systems, methodological limitations and sociocultural factors.

IMPLICATIONS

We identified five evidence-informed interventions to mitigate diagnostic delays: systematic consideration of multiple working hypotheses, development of sustainable local diagnostic capacity, enhancement of clinician-to-public-health communication networks, implementation of cognitive debiasing strategies, and strengthening of One Health surveillance platforms. Historical misdiagnoses offer crucial lessons for transforming outbreak response from reactive to anticipatory, potentially averting future epidemics through earlier, more accurate recognition of emerging pathogens within their complex ecological and social contexts.

Crystal structure of N-terminally hexahistidine-tagged Onchocerca volvulus macrophage migration inhibitory factor-1

Onchocerca volvulus causes blindness, onchocerciasis, skin infections and devastating neurological diseases such as nodding syndrome. New treatments are needed because the currently used drug, ivermectin, is contraindicated in pregnant women and those co-infected with Loa loa. The Seattle Structural Genomics Center for Infectious Disease (SSGCID) produced, crystallized and determined the apo structure of N-terminally hexahistidine-tagged O. volvulus macrophage migration inhibitory factor-1 (His-OvMIF-1). OvMIF-1 is a possible drug target. His-OvMIF-1 has a unique jellyfish-like structure with a prototypical macrophage migration inhibitory factor (MIF) trimer as the `head' and a unique C-terminal `tail'. Deleting the N-terminal tag reveals an OvMIF-1 structure with a larger cavity than that observed in human MIF that can be targeted for drug repurposing and discovery. Removal of the tag will be necessary to determine the actual biological oligomer of OvMIF-1 because size-exclusion chomatographic analysis of His-OvMIF-1 suggests a monomer, while PISA analysis suggests a hexamer stabilized by the unique C-terminal tails.

Diagnosis and Classification of Pediatric Epilepsy in Sub-Saharan Africa: A Comprehensive Review

Background/Objectives: Epilepsy is a major public health issue in Sub-Saharan Africa, particularly among children, due to limited healthcare resources, socioeconomic inequalities, and cultural stigma that often result in underdiagnosis and undertreatment. This review examines pediatric epilepsy's diagnosis, classification, and management in this setting, highlighting the need for culturally appropriate interventions to improve care quality and address these challenges. Methods: A review of the literature was conducted using MEDLINE, Embase, Scopus, and Web of Science databases to identify pertinent studies published between 2013 and 2024. This review included studies examining the epidemiology, seizure classification and etiologies of epilepsy among children in Sub-Saharan Africa. Results: This review revealed higher incidence and prevalence of epilepsy in Sub-Saharan Africa compared to high-income countries, primarily attributable to factors such as infectious diseases, perinatal injuries, and limited diagnostic resources. The most frequently reported types of epilepsy were generalized and focal seizures, with significant etiological contributions from structural and infectious causes, including nodding syndrome and HIV-related epilepsy. The treatment gap remains considerable, with up to 80% of children not receiving appropriate antiseizure medications. Conclusions: The diagnosis and treatment of epilepsy in pediatric populations in Sub-Saharan Africa is complicated by several factors, including cultural stigma and the lack of adequate healthcare infrastructure. There is an urgent need for culturally tailored diagnostic tools, improved access to affordable treatments, and public health initiatives aimed at reducing stigma. Addressing these gaps through enhanced research, improved healthcare access, and targeted educational campaigns is crucial for improving the quality of life for children with epilepsy.

Doxycycline, a role in the treatment of onchocerciasis-associated epilepsy?

Can the antibiotic doxycycline unlock new possibilities in the fight against onchocerciasis-associated epilepsy (OAE)? Idro et al. explored this question by investigating for the first time doxycycline's impact on nodding syndrome (NS), a severe manifestation of OAE. Results reveal significant findings that may shape future treatment strategies.

Onchocerciasis-associated epilepsy: Charting a path forward

This narrative review intends to inform neurologists and public health professionals about Onchocerciasis-Associated Epilepsy (OAE), a neglected public health problem in many remote onchocerciasis-endemic areas. For epidemiological purposes, we define OAE as sudden-onset of convulsive and non-convulsive seizure types, including head nodding seizures (nodding syndrome) in a previously healthy child aged 3 to 18 years in the absence of any other obvious cause for epilepsy, all happening within an area with high ongoing Onchocerca volvulus transmission. Several OAE pathophysiological mechanisms have been proposed, but none has been proven yet. Recent population-based studies showed that strengthening onchocerciasis elimination programs was followed by a significant reduction in the incidence of OAE and nodding syndrome. Treating epilepsy in onchocerciasis-endemic regions is challenging. More advocacy is needed to provide uninterrupted, free access to anti-seizure medication to persons with epilepsy in these remote, impoverished areas. It is crucial todevelop policies and increase funding for the prevention and treatment of OAE to reduce the associated burden of disease, notably via the establishment of morbidity management and disability prevention programs (MMDP). Moreover, effective collaboration between onchocerciasis elimination and mental health programs is imperative to alleviate the burden of OAE. This synergy promises reciprocal advantages and underscores the need for a comprehensive approach to address this multifaceted challenge.

Chorioretinitis among Immigrant and Travellers. Comment on Mansour et al. Presumed Onchocerciasis Chorioretinitis Spilling over into North America, Europe and Middle East. Diagnostics 2023, 13, 3626

We read, with interest, the paper by Mansour et al [...].

Treatment and prevention of epilepsy in onchocerciasis-endemic areas is urgently needed

BACKGROUND

There is increasing epidemiological evidence supporting the association between onchocerciasis and seizures, reinforcing the concept of onchocerciasis-associated epilepsy (OAE). The aim of this paper is to provide an update on the new knowledge about OAE and to propose recommendations to the World Health Organization how to address this public health problem.

MAIN TEXT

During the 2nd International Workshop on OAE held on 19-21 September, 2023, in Antwerp, Belgium, participants recognised OAE as a substantial yet neglected public health problem, particularly in areas of sub-Saharan Africa where onchocerciasis remains hyperendemic. Evidence from prospective population-based studies suggest that strengthening onchocerciasis elimination efforts leads to a significant reduction of OAE incidence. There is a need to validate an OAE case definition to estimate the burden of disease and identify onchocerciasis-endemic areas requiring intensification of onchocerciasis elimination programmes and integration of epilepsy care. It is expected that raising awareness about OAE will boost the population uptake of ivermectin. The implementation of a community-based epilepsy treatment programme offering free anti-seizure medications (ASMs) has shown high effectiveness in reducing the frequency of seizures and improving the overall quality of life of people with epilepsy.

CONCLUSIONS

To reduce OAE burden, enhanced collaboration between onchocerciasis and mental health programmes at community, national, and international levels is required. Urgent efforts are needed to ensure the uninterrupted provision of free ASMs in onchocerciasis-endemic areas. Furthermore, OAE should be included in the quantification of the onchocerciasis disease burden.

Onchocerciasis-associated epilepsy: an explorative case-control study with viral metagenomic analyses on Onchocerca volvulus

Background

A high prevalence of onchocerciasis-associated epilepsy (OAE) has been observed in onchocerciasis-endemic areas with high ongoing Onchocerca volvulus transmission. However, the pathogenesis of OAE remains to be elucidated. We hypothesise that the O. volvulus virome could be involved in inducing epilepsy. With this study, we aim to describe the O. volvulus virome and identify potential neurotropic viruses linked to OAE.

Methods

In Maridi County, an onchocerciasis endemic area in South Sudan with a high prevalence of OAE, we will conduct an exploratory case-control study enrolling 40 persons aged 12 years and above with palpable onchocerciasis nodules. Cases will be participants with OAE (n=20), who will be age- and village-matched with controls without epilepsy (n=20). For each study participant, two skin snips at the iliac crest will be obtained to collect O. volvulus microfilariae, and one nodulectomy will be performed to obtain adult worms. A viral metagenomic study will be conducted on microfilariae and adult worms, and the O. volvulus virome of persons with and without OAE will be compared. The number, size, and localisation of onchocerciasis nodules in persons with and without OAE will be described. Moreover, the pre- and post-nodulectomy frequency of seizures in persons with OAE will be compared.

Ethics and dissemination

The protocol has been approved by the Ethics Committee of the University of Antwerp and the Ministry of Health of South Sudan. Findings will be disseminated nationally and internationally via meetings and peer-reviewed publications.

Registration

ClinicalTrials.gov registration NCT05868551 ( https://clinicaltrials.gov/study/NCT05868551).

Protocol version

1.1, dated 09/05/2023.