High infection rates for onchocerciasis and soil-transmitted helminthiasis in children under fve not receiving preventive chemotherapy:a bottleneck to elimination

Background:The current mainstay for control/elimination of onchocerciasis and soil-transmitted helminthiasis(STH)relies on ivermectin-and mebendazole/albendazole-based preventive chemotherapies.However,children under fve years of age have been excluded in both research activities and control programs,because they were believed to have insignifcant infection rates.There is therefore a need for up-to-date knowledge on the prevalence and inten‑sity of STH and onchocerciasis infections in this age group.This study aimed at assessing the rates and intensities of onchocerciasis and STH infections in children under fve years of age who are excluded from ivermectin-or mebenda‑zole/albendazole-based preventive chemotherapies.Methods:A series of cross-sectional surveys was conducted in four Health Districts in the Centre and Littoral Regions of Cameroon between 2018 and 2019.All subjects aged 2 to 4 years,were screened for prevalence(or infection rate)and intensity[number of eggs per gram of stool(epg)or number of microflariae per skin snip(mf/ss)]of STH and onchocerciasis infections respectively using the Kato-Katz and skin snip methodologies.Chi-square and the nonparametric tests(Mann Whitney and Kruskal Wallis)were used to compare infection rates and intensities of infections between Health Districts and genders,respectively.Results:A total of 421 children were enrolled in this study.The overall prevalence of onchocerciasis was 6.6%[95% confdence interval(CI):4.3‒9.9],ranging from 3.6%(in the Ntui Health District)to 12.2%(in the Bafa Health District).The intensity of infection ranged from 0.5 to 46 microflariae per skin snip[median:5;interquartile range(IQR):2.25‒8.5].The overall prevalence of STH was 9.6%(95%CI:6.5‒13.9),with a high infection rate(29.6%)in the Akonolinga Health District.Two STH species(Ascaris lumbricoides and Trichuris trichiura)were found among infected individuals.The median intensities of STH infections were 1,992 epg(IQR:210‒28,704)and 96 epg(IQR:48‒168)for A.lumbricoides and T.trichiura,respectively.Conclusions:This study reveals that children<5 years of age are highly infected with STH and onchocerciasis,and could contribute to the spread of these diseases,perpetuating a vicious circle of transmission and hampering elimi‑nation eforts.These fndings reveal the urgent need to provide(or scale)treatments(likely pediatric formulations)to these preschool-aged children,especially in areas of high transmission,to accelerate eforts to reach WHO 2030 target.

Report of the first international workshop on onchocerciasis-associated epilepsy

Background:Recently,several epidemiological studies performed in Onchocerca volvulus-endemic regions have suggested that onchocerciasis-associated epilepsy(OAE)may constitute an important but neglected public health problem in many countries where onchocerciasis is still endemic.Main text:On October 12-14th 2017,the first international workshop on onchocerciasis-associated epilepsy(OAE)was held in Antwerp,Belgium.The workshop was attended by 79 participants from 20 different countries.Recent research findings strongly suggest that O.volvulus is an important contributor to epilepsy,particularly in meso-and hyperendemic areas for onchocerciasis.Infection with O.volvulus is associated with a spectrum of epileptic seizures,mainly generalised tonic-clonic seizures but also atonic neck seizures(nodding),and stunted growth.OAE is characterised by an onset of seizures between the ages of 3-18 years.Multidisciplinary working groups discussed topics such as how to 1)strengthen the evidence for an association between onchocerciasis and epilepsy,2)determine the burden of disease caused by OAE,3)prevent OAE,4)improve the treatment/care for persons with OAE and affected families,5)identify the pathophysiological mechanism of OAE,and 6)deal with misconceptions,stigma,discrimination and gender violence associated with OAE.An OAE Alliance was created to increase awareness about OAE and its public health importance,stimulate research and disseminate research findings,and create partnerships between OAE researchers,communities,advocacy groups,ministries of health,non-governmental organisations,the pharmaceutical industry and funding organizations.Conclusions:Although the exact pathophysiological mechanism underlying OAE remains unknown,there is increasing evidence that by controlling and eliminating onchocerciasis,OAE will also disappear.Therefore,OAE constitutes an additional argument for strengthening onchocerciasis elimination efforts.Given the high numbers of people with epilepsy in O.volvulus-endemic regions,more advocacy is urgently needed to provide anti-epileptic treatment to improve the quality of life of these individuals and their families.