Impact of annual community-directed treatment with ivermectin on the incidence of epilepsy in Mvolo, a two-year prospective study.

OBJECTIVES: The potential impact of cumulative community-directed treatment with ivermectin (CDTI) on epilepsy epidemiology in Mvolo County, South Sudan, an onchocerciasis-endemic area with high epilepsy prevalence, was investigated. Annual CDTI was introduced in 2002 in Mvolo, with interruptions in 2016 and 2020. METHODS: Comprehensive house-to-house surveys in Mvolo (June 2020 and 2022) identified cases of epilepsy, including probable nodding syndrome (pNS). Community workers screened households in selected sites for suspected epilepsy, and medical doctors confirmed the diagnosis and determined the year of seizure onset. The incidence of epilepsy, including pNS, was analysed using 95% confidence intervals (CIs). Data on ivermectin intake and onchocerciasis-associated manifestations (itching and blindness) were collected. RESULTS: The surveys covered 15,755 (2020) and 15,092 (2022) individuals, identifying 809 (5.2%, 95% CI: 4.8-5.5%) and 672 (4.5%, 95% CI: 4.1-4.8%) epilepsy cases, respectively. Each survey reported that a third of the surveyed population experienced skin itching, and 3% were blind. Epilepsy incidence per 100,000 person-years gradually declined, from 326.5 (95% CI: 266.8-399.1) in 2013-2015 to 96.6 (95% CI: 65.5-141.7) in 2019-2021. Similarly, pNS incidence per 100,000 person-years decreased from 151.7 (95% CI: 112.7-203.4) to 27.0 (95% CI: 12.5-55.5). Coverage of CDTI was suboptimal, reaching only 64.0% of participants in 2019 and falling to 24.1% in 2021 following an interruption in 2020 due to COVID-19 restrictions. Additionally, while 99.4% of cases had active epilepsy in 2022, less than a quarter of these had access to antiseizure medication. CONCLUSIONS: The observed decrease in epilepsy incidence despite suboptimal CDTI coverage highlights the potential impact of onchocerciasis control efforts and underscores the need to strengthen these efforts in Mvolo County and across South Sudan. As a proactive measure, Mvolo and neighbouring counties are transitioning to biannual CDTI. Furthermore, the substantial epilepsy treatment gap in Mvolo should be addressed.

Effect of onchocerciasis elimination measures on the incidence of epilepsy in Maridi, South Sudan: a 3-year longitudinal, prospective, population-based study.

BACKGROUND: High onchocerciasis transmission predisposes endemic communities to a high epilepsy burden. The 4·4% epilepsy prevalence documented in 2018 in Maridi, South Sudan, prompted the strengthening of onchocerciasis elimination measures. Community-directed treatment with ivermectin was implemented annually in 2017, 2018, and 2019, interrupted in 2020, and re-implemented biannually in 2021. We aimed to assess the effect of these interventions, along with slash and clear vector control on the incidence of epilepsy, including nodding syndrome. METHODS: In this longitudinal, prospective, population-based study, we did a two-stage house-to-house epilepsy survey before (May 10-30, 2018) and after (March 9-19, 2022) the strengthening of onchocerciasis elimination interventions in South Sudan. Strengthening also included the implementation of a community-based slash and clear vector control method that we initiated in 2019 at the Maridi dam (the main blackfly breeding site). Eight sites were surveyed near the Maridi dam and inclusion required residence in one of these sites. All household residents were first screened by community workers, followed by confirmation of the epilepsy diagnosis by trained clinicians. The primary outcome was epilepsy incidence, including nodding syndrome, which was assessed via self-reported new-onset epilepsy in the previous 4 years of each survey, confirmed by clinician assessment. FINDINGS: The preintervention survey included 17 652 people of whom 736 had epilepsy (315 female and 421 male), and the post-intervention survey included 14 402 people of whom 586 had epilepsy (275 female and 311 male). When biannual community-directed treatment with ivermectin was initiated in 2021, the intervention's coverage rose by 15·7% (95% CI 14·6-16·8); although only 56·6% of the population took ivermectin in 2021. Between 2018 and 2022, epilepsy incidence decreased from 348·8 (307·2-395·8) to 41·7 (22·6-75·0) per 100 000 person-years. Similarly, the incidence of nodding syndrome decreased from 154·7 (127·6-187·3) to 10·4 (2·7-33·2) per 100 000 person-years. The identified risk factors for epilepsy were: living closer to the Maridi dam, being aged between 6 and 40 years, not taking ivermectin, and being male. INTERPRETATION: In onchocerciasis-endemic areas with high epilepsy prevalence, strengthening onchocerciasis elimination interventions can decrease the incidence of epilepsy, including nodding syndrome. Additional efforts are needed to increase community-directed treatment with ivermectin coverage and sustain blackfly control in Maridi. FUNDING: Research for Health in Humanitarian Crisis, European Research Council, Research Foundation-Flanders, Research Foundation-Flanders, the Italian Agency for Development Cooperation, and La Caixa Foundation.

Ivermectin treatment response in two rural villages with a high prevalence of onchocerciasis and epilepsy, Mahenge Tanzania.

Background: Despite 20 years of ivermectin mass distribution in the Mahenge area, Tanzania, the prevalence of onchocerciasis and epilepsy has remained high in rural villages. Objectives: We investigated the efficacy of ivermectin in reducing Onchocerca volvulus microfilariae and predictors for parasitic load following ivermectin treatment in persons with (PWE) and without epilepsy (PWOE). Methods: Between April and September 2019, 50 PWE and 160 randomly selected PWOE from Msogezi and Mdindo villages participated in a follow-up study. Skin snips were obtained pre (baseline) and three months post-ivermectin treatment. Results: The overall prevalence of O. volvulus positive skin snips at baseline was 49% (103/210), with no significant difference between PWE (58.0%) and PWOE (46.3%); p=0.197. The overall mean microfilarial density was significantly higher at baseline 1.45(95%CI:0.98-2.04)) than three-month post-ivermectin treatment (0.23(95%CI:0.11-0.37), p<0.001. Three months after ivermectin, the microfilarial density had decreased by ≥80% in 54 (81.8%, 95%CI: 72.3-91.4) of the 66 individuals with positive skin snips at baseline. High microfilarial density at baseline was the only significant predictor associated with higher microfilarial density in the post-ivermectin skin snips. Conclusion: Our study reports a decrease in microfilarial density following ivermectin treatment in most individuals. Optimizing ivermectin coverage will address the ongoing onchocerciasis transmission in Mahenge.

Level and Determinants of Adherence to COVID-19 Preventive Measures in the First Stage of the Outbreak in Uganda.

We conducted an online survey in the first two months of the Coronavirus Disease 2019 (COVID-19) epidemic in Uganda to assess the level and determinants of adherence to and satisfaction with the COVID-19 preventive measures recommended by the government. We generated Likert scales for adherence and satisfaction outcome variables and measured them with four preventive measures, including handwashing, wearing face masks, physical distancing, and coughing/sneezing hygiene. Of 1726 respondents (mean age: 36 years; range: 12-72), 59% were males, 495 (29%) were adherent to, and 545 (32%) were extremely satisfied with all four preventive measures. Adherence to all four measures was associated with living in Kampala City Centre (AOR: 1.7, 95% CI: 1.1-2.6) and receiving COVID-19 information from health workers (AOR: 1.2, 95% CI: 1.01-1.5) or village leaders (AOR: 1.4, 95% CI: 1.02-1.9). Persons who lived with younger siblings had reduced odds of adherence to all four measures (AOR: 0.75, 95% CI: 0.61-0.93). Extreme satisfaction with all four measures was associated with being female (AOR: 1.3, 95% CI: 1.1-1.6) and health worker (AOR: 1.2, 95% CI: 1.0-1.5). Experiencing violence at home (AOR: 0.25, 95% CI: 0.09-0.67) was associated with lower satisfaction. Following reported poor adherence and satisfaction with preventive measures, behavior change programs using health workers should be expanded throughout, with emphasis on men.

Focus of Ongoing Onchocerciasis Transmission Close to Bangui, Central African Republic.

Recently, there were anecdotal reports of a high number of persons with epilepsy, including children with nodding seizures in the Landja Mboko area located about 9 km from the capital city Bangui, Central African Republic. We suspected the area to be endemic for onchocerciasis, and that the alleged increase in the number of epilepsy cases was due to ongoing Onchocerca volvulus transmission. However, ivermectin mass drug distribution (MDA) had never been implemented in the area. Therefore we performed an Ov16 antibody prevalence study among children, aged 6-9 years, using the biplex rapid diagnostic test (SD Bioline Oncho/LF biplex IgG4 RDT). The overall Ov16 seroprevalence was 8.9%, and that of lymphatic filariasis (LF) was 1.9%. Ov16 seropositivity was highest in Kodjo (20.0%), a village close to rapids on the river. Our study shows that there is ongoing O. volvulus transmission in the Landja Mboko area. We recommend that the extent of this onchocerciasis focus should be mapped, and the introduction of ivermectin MDA should be considered in these communities.