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.

Case definitions for onchocerciasis-associated epilepsy and nodding syndrome: A focused review.

Onchocerciasis-associated epilepsy (OAE) is an important but neglected public health problem in onchocerciasis-endemic areas with insufficient or inadequate onchocerciasis control. Hence, there is a need for an internationally accepted, easy-to-use epidemiological case definition of OAE to identify areas of high Onchocerca volvulus transmission and disease burden requiring treatment and prevention interventions. By including OAE as a manifestation of onchocerciasis, we will considerably improve the accuracy of the overall onchocerciasis disease burden, which is currently underestimated. Hopefully, this will lead to increased interest and funding for onchocerciasis research and control interventions, notably the implementation of more effective elimination measures and treatment and support for affected individuals and their families.

The Role of the Maridi Dam in Causing an Onchocerciasis-Associated Epilepsy Epidemic in Maridi, South Sudan: An Epidemiological, Sociological, and Entomological Study.

Background: An epilepsy prevalence of 4.4% was documented in onchocerciasis-endemic villages close to the Maridi River in South Sudan. We investigated the role of the Maridi dam in causing an onchocerciasis-associated epilepsy epidemic in these villages. Methods: Affected communities were visited in November 2019 to conduct focus group discussions with village elders and assess the OV16 seroprevalence in 3- to 9-year-old children. Entomological assessments to map blackfly breeding sites and determine biting rates around the Maridi River were conducted. Historical data regarding various activities at the Maridi dam were obtained from the administrative authorities. Results: The Maridi dam was constructed in 1954-1955. Village elders reported an increasing number of children developing epilepsy, including nodding syndrome, from the early 1990s. Kazana 2 (the village closest to the dam; epilepsy prevalence 11.9%) had the highest OV16 seroprevalence: 40.0% among children 3-6 years old and 66.7% among children 7-9 years old. The Maridi dam spillway was found to be the only Simulium damnosum breeding site along the river, with biting rates reaching 202 flies/man/h. Conclusion: Onchocerciasis transmission rates are high in Maridi. Suitable breeding conditions at the Maridi dam, coupled with suboptimal onchocerciasis control measures, have probably played a major role in causing an epilepsy (including nodding syndrome) epidemic in the Maridi area.

Low ivermectin use among 5- to 6-year-old children: observations from door-to-door surveys in onchocerciasis-endemic regions in Africa.

During door-to-door surveys in onchocerciasis-endemic regions in Africa, the age-specific ivermectin coverage in 29 722 individuals was assessed. Children 5-6 y of age had significantly lower coverage compared with older participants. Insufficient ivermectin intake among young children could prolong onchocerciasis elimination prospects, as they may serve as human reservoirs of Onchocerca volvulus; moreover, it increases the risk of developing onchocerciasis-associated epilepsy (OAE). The causes of the low ivermectin coverage observed among children 5-6 y of age need to be explored. Integrating ivermectin distribution into chemoprophylaxis strategies for other neglected diseases could increase coverage in a cost-effective manner.

Nodding syndrome research, lessons learned from the NSETHIO project.

BACKGROUND: Until recently, nodding syndrome (NS) was considered as a mysterious disease of unknown etiology. A link between onchocerciasis and epilepsy was suspected for a long time. However, onchocerciasis was not considered as the cause of NS because NS was believed to occur only in onchocerciasis-endemic regions in Uganda, South Sudan, and Tanzania. In October 2015, with funding from the European Research Council, the NSETHIO group launched a trans-disciplinary, multi-country research project to identify the cause of NS and to study the link between onchocerciasis and epilepsy. METHODS: We reviewed NSETHIO activities as well as all published papers, and compared project findings with results of previous research on NS. RESULTS: Findings from the NSETHIO project showed that NS is only one of the clinical manifestations in the wide spectrum of onchocerciasis-associated epilepsy (OAE) that could be prevented by strengthening onchocerciasis elimination programs. NSETHIO demonstrated that OAE is an important neglected public health problem in onchocerciasis-endemic areas with no or a sub-optimally functioning onchocerciasis control strategies. CONCLUSIONS: Today there is overwhelming evidence that NS together with the Nakalanga syndrome is clinical presentations of OAE, a condition that could be prevented by strengthening onchocerciasis elimination programs. While research needs to continue to elucidate the pathophysiological mechanisms causing NS, new strategies to accelerate onchocerciasis elimination coupled with community-based surveillance and treatment programs for epilepsy are urgently needed in areas of high Onchocerca volvulus transmission.

Early childhood transmission of hepatitis B prior to the first hepatitis B vaccine dose is rare among babies born to HIV-infected and non-HIV infected mothers in Gulu, Uganda.

BACKGROUND: Hepatitis B (HBV) in sub-Saharan Africa is believed to be horizontally acquired. However, because of the high HBV prevalence in northern Uganda, no hepatitis B vaccination at birth and no access to HBV immunoglobulin, we hypothesize that vertical transmission also could also play an important role. We therefore investigated the incidence of HBV among babies presenting for their first HBV vaccine dose in Gulu, Uganda. METHODS: We recruited mothers and their babies (at least 6-week old) presenting for their postnatal care and first HBV vaccine dose respectively. Socio-demographic and risk factors for HBV transmission were recorded. Mothers were tested for Hepatitis B core antibody (anti-HBc-IgG) and hepatitis B surface antigen (HBsAg). HBsAg-positive sera were tested for hepatitis B e antigen (HBeAg) and HBV viral load (HBVDNA). Babies were tested for HBsAg at presentation and at the last immunization visit. A sample of HBsAg-negative babies were tested for HBVDNA. Incident HBV infection was defined by either a positive HBsAg or HBVDNA test. Chi-square or fisher's exact tests were utilized to investigate associations and t-tests or Wilcoxon rank-sum test for continuous differences. RESULTS: We recruited 612 mothers, median age 23years (IQR 20-28). 53 (8.7%) were HBsAg-positive and 339 (61.5%) were anti-HBc-IgG-positive. Ten (18.9%) of the HBsAg-positive mothers were HBeAg-positive. Median HBVDNA levels of HBV-infected mothers was 5.7log (IQR 4.6-7.0) IU/mL with 9 (17.6%) having levels≥105IU/mL. Eighty (13.3%) mothers were HIV-infected of whom 9 (11.5%) were co-infected with HBV. No baby tested HBsAg or HBVDNA positive. CONCLUSION: Vertical transmission does not seem to contribute substantially to the high HBV endemicity in northern Uganda. The current practice of administering the first HBV vaccine to babies in Uganda at six weeks of age may be adequate in control of HBV transmission.

Improved Adherence to Antiretroviral Therapy Observed Among HIV-Infected Children Whose Caregivers had Positive Beliefs in Medicine in Sub-Saharan Africa.

A high level of adherence to antiretroviral treatment is essential for optimal clinical outcomes in HIV infection, but measuring adherence is difficult. We investigated whether responses to a questionnaire eliciting caregiver beliefs in medicines were associated with adherence of their child (median age 2.8 years), and whether this in turn was associated with viral suppression. We used the validated beliefs in medicine questionnaire (BMQ) to measure caregiver beliefs, and medication event monitoring system caps to measure adherence. We found significant associations between BMQ scores and adherence, and between adherence and viral suppression. Among children initiating Antiretroviral therapy (ART), we also found significant associations between BMQ 'necessity' scores, and BMQ 'necessity-concerns' scores, and later viral suppression. This suggests that the BMQ may be a valuable tool when used alongside other adherence measures, and that it remains important to keep caregivers well informed about the long-term necessity of their child's ART.

Nodding Syndrome in Onchocerciasis Endemic Areas.

High prevalence of nodding syndrome (NS) and other types of epileptic seizures have been reported in many onchocerciasis endemic regions in Africa for decades. To improve quality of life of affected patients and families, there is an urgent need to unravel the relationship between these epileptic disorders and onchocerciasis, and to design treatment and prevention strategies.

Systematic screening for drug-resistant tuberculosis with Xpert(®) MTB/RIF in a referral hospital in Cambodia.

SETTING: Limited access to drug susceptibility testing (DST) in referral hospitals contributes to delayed detection of multidrug-resistant tuberculosis (MDR-TB). OBJECTIVE: To document the impact of identifying rifampicin (RMP) resistance using Xpert(®) MTB/RIF on time to diagnosis and time to treatment, and evaluate its performance under programmatic conditions. METHODS: Using a prospective observational study, we screened presumptive MDR-TB cases with Xpert and solid culture/conventional DST. RMP resistance was confirmed using a line-probe assay (LPA). We recorded diagnostic and treatment delays. We performed rpoB gene sequencing post hoc to resolve discordant RMP susceptibilities. RESULTS: We screened 299 of 345 presumptive MDR-TB individuals, and identified 44 Xpert RMP-resistant cases: 16/165 (10%) were new and 28/136 (20%) retreated. The median time to diagnosis was 2 days (Xpert) vs. an additional 6 with LPA; the median time to treatment was 14 days. Confirmatory LPA on 39/44 revealed 27 concordant, 6 discordant and 6 invalid results. Xpert RMP resistance was confirmed in respectively 24/30 (80%) and 21/23 (91%) by phenotypic DST and rpoB sequencing. CONCLUSION: Screening presumptive MDR-TB patients with Xpert enabled rapid diagnosis and treatment of MDR-TB. Xpert performed well, provided appropriate risk assessment was done. Rapid confirmatory testing added little to clinical decision making. Our findings support the latest World Health Organization guidelines to abandon confirmatory LPA in favour of repeat Xpert when in clinical doubt, pending phenotypic DST.

Population level usage of health services, and HIV testing and care, prior to decentralization of antiretroviral therapy in Agago District in rural Northern Uganda.

BACKGROUND: Decentralization of ART services scaled up significantly with the country wide roll out of option B plus in Uganda. Little work has been undertaken to examine population level access to HIV care particularly in hard to reach areas in rural Africa. Most work on ART scale up has been done at health facility level which omits people not accessing healthcare in the community. This study describes health service usage, particularly HIV testing and care in 2/6 parishes of Lapono sub-county of northern Uganda, prior to introduction of ART services in Lira Kato Health Centre (a local lower-level health centre III), as part of ART decentralization. METHODS: Household and individual questionnaires were administered to household members (aged 15-59 years). Logit random effects models were used to test for differences in proportions (allowing for clustering within villages). RESULTS: 2124 adults from 1351 households were interviewed (755 [36%] males, 1369 [64 %] females). 2051 (97%) participants reported seeking care locally for fever, most on foot and over half at Lira Kato Health Centre. 574 (76%) men and 1156 (84%) women reported ever-testing for HIV (P < 0.001 for difference); 34/574 (6%) men and 102/1156 (9%) women reported testing positive (P = 0.04). 818/850 (96%) women who had given birth in the last 5 years had attended antenatal care in their last pregnancy: 7 women were already diagnosed with HIV (3 on ART) and 790 (97%) reported being tested for HIV (34 tested newly positive). 124/136 (91%) HIV-positive adults were in HIV-care, 123/136 (90 %) were taking cotrimoxazole and 74/136 (54%) were on ART. Of adults in HIV-care, most were seen at Kalongo hospital (n = 87), Patongo Health Centre (n = 7) or Lira Kato Health Centre (n = 23; no ART services). 58/87, 5/7 and 20/23 individuals walked to Kalongo hospital (56 km round-trip, District Health Office information), Patongo Health Centre (76 km round-trip, District Health Office information) and Lira Kato Health Centre (local) respectively. 8 HIV-infected children were reported; only 2 were diagnosed aged <24 months: 7/8 were in HIV-care including 3 on ART. CONCLUSIONS: Higher proportions of women compared to men reported ever-testing for HIV and testing HIV-positive, similar to other surveys. HIV-infected men and women travelled considerable distances for ART services. Children appeared to be under-accessing testing and referral for treatment. Decentralization of ART services to a local health facility would decrease travel time and transport costs, making care and treatment more easily accessible.

Nodding syndrome since 2012: recent progress, challenges and recommendations for future research.

We aim to review the current epidemiology of nodding syndrome (NS) and discuss relevant gaps in research. NS and convulsive epilepsy of unknown aetiology are clustered within the same villages and families in onchocerciasis-endemic areas. They are therefore potentially different clinical expressions of the same disease. It has been difficult to perform full autopsies on NS patients who die in remote villages. Adequate fixation of tissue immediately after death is critical for the examination of brain tissue. Therefore, post-mortem transsphenoidal brain biopsies, performed immediately after death by trained nurses, will provide the best option for obtaining tissue for analysis. We suspect that certain blackflies in onchocerciasis-endemic areas may transmit a novel pathogen that could cause NS and epilepsy. This is supported by a recent drop in the number of new NS cases coinciding with vector control activities aimed at reducing blackfly populations in northern Uganda. We propose that metagenomic studies of human samples, blackflies and microfilariae are conducted to screen for pathogens, and that a clinical trial is planned to evaluate the impact of larviciding against NS and epilepsy epidemics.