Burden and factors associated with schistosomiasis and soil-transmitted helminth infections among school-age children in Huambo,Uige and Zaire provinces,Angola

Background:Schistosomiasis and soil-transmitted helminths(STHs)contribute high disease burdens amongst the neglected tropical diseases(NTDs)and are public health problems in Angola.This study reports the prevalence,intensity and risk factors for schistosomiasis and STH infection in Huambo,Uige and Zaire provinces,Angola,to inform a school-based preventive chemotherapy program.Methods:A two-stage cluster design was used to select schools and schoolchildren to participate in parasitological and water,sanitation and hygiene(WASH)surveys across Huambo,Uige,and Zaire provinces.Point-of-care circulating cathodic antigen and urinalysis rapid diagnostic tests(RDTs)were used to determine the prevalence of Schistosoma mansoni and S.haematobium,respectively.Kato-Katz was used to identify and quantify STH species and quantify and compare with RDTs for S.mansoni.Urine filtration was used to quantify and compare with RDTs for S.haematobium.Descriptive statistics were used for prevalence and infection intensity of schistosomiasis and STH infection.Performance of RDTs was assessed through specificity and Cohen’s Kappa agreement with microscopy.A multivariate regression analysis was used to determine demographic and WASH factors associated with schistosomiasis and STH infection.Results:A total 575 schools and 17,093 schoolchildren participated in the schistosomiasis survey,of which 121 schools and 3649 schoolchildren participated in the STH survey.Overall prevalence of S.mansoni was 21.2%(municipality range 0.9–74.8%)and S.haematobium 13.6%(range 0–31.2%),with an overall prevalence of schistosomiasis of 31.4%(range 5.9–77.3%).Overall prevalence of Ascaris lumbricoides was 25.1%(range 0–89.7%),hookworm 5.2%(range 0–42.6%),and Trichuris trichiura 3.6%(range 0–24.2%),with an overall prevalence of STH infection of 29.5%(range 0.8–89.7%).Ecological zone and ethnicity were factors associated with schistosomiasis and STH infection,with older age and female sex additional risk factors for S.haematobium.Conclusions:Most municipalities met World Health Organization defined prevalence thresholds for a schistosomiasis preventive chemotherapy program.A STH preventive chemotherapy program is indicated for nearly all municipalities in Uige and select municipalities in Huambo and Zaire.The association between ecological zone and ethnicity with schistosomiasis and STH infection necessitates further evaluation of home and school environmental,sociodemographic and behavioural factors to inform targeted control strategies to complement preventive chemotherapy programs.

Neglected tropical diseases activities in Africa in the COVID-19 era:the need for a"hybrid" approach in COVID-endemic times

With the coronavirus disease 2019(COVID-19)pandemic showing no signs of abating,resuming neglected tropical disease(NTD)activities,particularly mass drug administration(MDA)Z is vital.Failure to resume activities will not only enhance the risk of NTD transmission,but will fail to leverage behaviour change messaging on the importance of hand and face washing and improved sanitation--a common strategy for several NTDs that also reduces the risk of COVID-19 spread.This so-called"hybrid approach"will dem on strate best practices for mitigating the spread of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)by incorporating physical distancing,use of masks,and frequent hand-washing in the delivery of medicines to endemic communities and support action against the transmission of the virus through water,sanitation and hygiene interventions promoted by NTD programmes.Unless MDA and morbidity management activities resume,achievement of NTD targets as projected in the WHO/NTD Roadmap(2021-2030)will be deferred,the aspirational goal of NTD programmes to enhance universal health coverage jeopardised and the call to leave no one behind'a hollow one.We outline what implementing this hybrid approach,which aims to strengthen health systems,and facilitate integration and cross-sector collaboration,can achieve based on work undertaken in several African countries.

Risk factors for schistosomiasis in an urban area in northern Cote d’Ivoire

Background:Schistosomiasis is a water-based disease transmitted by trematodes belonging to the genus Schistosoma.The aim of this study was to assess the relationship between the prevalence of schistosomiasis and access to water,sanitation and hygiene(WASH)and environmental and socioeconomic factors in the city of Korhogo,northern Côte d'Ivoire.Methods:A cross-sectional study including 728 randomly selected households was conducted in Korhogo in March 2015.The heads of the households were interviewed about access to WASH and environmental and socioeconomic factors.All children abed between 5 and 15 years living in the households were selected to provide stool and urine samples for parasitological diagnosis of Schistosoma mansoni and Schistosoma haematobium infection.The relationship between infection with S.mansoni and potential risk factors was analysed by a mixed logistic regression model with‘household’as a random factor.Likelihood ratio tests were used to identify factors that were significantly associated with a Schistosoma spp.infection.Results:The overall prevalence of schistosomiasis among school-aged children in Korhogo was 1.9%(45/2341)composed of 0.3%(3/1248)S.haematobium and 3.5%(42/1202)S.mansoni.Due to the low prevalence of S.haematobium infection,risk factor analysis was limited to S.mansoni.Boys were 7.8 times more likely to be infected with S.mansoni than girls.Children between 10 and 15 years of age were 3.8 times more likely to be infected than their younger counterparts aged 5-10 years.Moreover,living in a house further away from a water access point(odds ratio[OR]=0.29,95%confidence interval[CI]:0.13-0.70)and abstaining from swimming in open freshwater bodies(OR=0.16,95%CI:0.04-0.56)were significantly associated with decreased odds of S.mansoni infection.The socioeconomic status did not appear to influence the prevalence of S.mansoni.Conclusions:A strategy to reduce the incidence of schistosomiasis should focus on health education to change the behaviour of populations at risk and encourage communities to improve sanitation and infrastructure in order to reduce contact with surface water.

Soil-transmitted helminth infection in school age children in Sierra Leone after a decade of preventive chemotherapy interventions

Background:Baseline mapping of soil-transmitted helminth(STH)infections among school age children(SAC)in 2008-2009 found high or moderate prevalence in 13 of the 14 districts in Sierra Leone.Following these surveys,mass drug administration(MDA)of mebendazole/albendazole was conducted biannually at national level targeting pre-school children(PSC)aged 12-59 months and intermittently at sub-national level targeting SAC.In addition,MDA with ivermectin and albendazole for eliminating lymphatic filariasis(LF)has been conducted nationwide since 2010 targeting individuals over 5 years of age.Each MDA achieved high coverage,except in 2014 when all but one round of MDA for PSC was cancelled due to the Ebola emergency.The objective of the current study was to determine the prevalence and intensity of STH infections among SAC after a decade of these deworming campaigns.Methods:Seventy-three schools in 14 districts were purposefully selected,including 39 schools from the baseline surveys,with approximately two sites from each of low,moderate and high prevalence categories at baseline per district.Fresh stool samples were collected from 3632 children aged 9-14 years(male 51%,female 49%)and examined using the Kato Katz technique.Results:The prevalence of STH infections in Sierra Leone decreased in 2016 compared to 2008:Ascaris lumbricoides 4.4%(95%confidence interval[CI]:3.7-5.1%)versus 6.6%(95%CI:0-25%),Trichuris trichiura 0.7%(95%CI:0.5-1.1%)versus 1.8%(95%CI:0-30.2%),hookworm 14.9%(95%CI:13.8-16.1)versus 38.5%(95%CI:5.4-95.1%),and any STH 18.3%(95%CI:17.0-19.5%)versus 48.3%(CI:5.4-96.3%),respectively.In 2016,no district had high hookworm prevalence and four districts had moderate prevalence,compared with eight and four districts respectively in 2008.In 2016,the arithmetic mean hookworm egg count in all children examined was light:45.5 eggs per gram(EPG)of faeces,(95%CI:\35.96-55.07 EPG);three(0.08%)children had heavy infections and nine(0.25%)children had moderate infections.Conclusions:Sierra Leone has made considerable progress toward controlling STH as a public health problem among SAC.As LF MDA phases out(between 2017 and 2021),transition of deworming to other platforms and water and sanitation strategies need to be strengthened to maintain STH control and ultimately interrupt transmission.