Distribution of Plasmodium spp.infection in asymptomatic carriers in perennial and low seasonal malaria transmission settings in West Africa

countries in West Africa remain a hotspot for malaria with all age groups at risk.Asymptomatic carriers of Plasmodium spp.are important sources of infections for malaria vectors and thus contribute to the anchoring of the disease in favourable eco-epidemiological settings.The objective of this study was to assess the asymptomatic malaria case rates in Korhogo and Kaedi,two urban areas in northern Côte d’Ivoire and southern Mauritania,respectively.Methods:Cross-sectional surveys were carried out during the rainy season in 2014 and the dry season in 2015 in both settings.During each season,728 households were randomly selected and a household-based questionnaire was implemented to collect demographic and epidemiological data,including of malaria preventive methods used in communities.Finger-prick blood samples were obtained for biological examination using microscopy and rapid diagnostic tests(RDTs).Results:Overall,2672 households and 15858 consenting participants were surveyed.Plasmodium spp.infection was confirmed in 12.4%(n=832)and 0.3%(n=22)of the assessed individuals in Korhogo and Kaedi,respectively.In Korhogo,the prevalence of asymptomatic malaria was 10.5%(95%CI:9.7-11.2)as determined by microscopy and 9.3%(95%CI:8.6-10.0%)when assessed by RDT.In Kaedi,asymptomatic malaria prevalence was 0.2%(95%CI:0.1-0.4%)according to microscopy,while all RDTs performed were negative(n=8372).In Korhogo,asymptomatic malaria infection was significantly associated with age and season,with higher risk within the 5-14 years-old,and during the rainy season.In Kaedi,the risk of asymptomatic malaria infection was associated with season only(higher during the dry season;crude OR(cOR):6.37,95%CI:1.87-21.63).P.falciparum was the predominant species identified in both study sites representing 99.2%(n=825)in Korhogo and 59.1%(n=13)in Kaedi.Gametocytes were observed only in Korhogo and only during the rainy season at 1.3%(95%CI:0.7-2.4%).Conclusions:Our findings show a low prevalence of clinical malaria episodes with a significant proportion of asymptomatic carriers in both urban areas.National policies for malaria infections are focused on treatment of symptomatic cases.Malaria control strategies should be designed for monitoring and managing malaria infections in asymptomatic carriers.Additional measures,including indoor residual spraying,effective use of long-lasting insecticidal nets is strongly needed to reduce the number of Plasmodium spp.infections in Korhogo and Kaedi.

Community knowledge,attitudes and practices related to schistosomiasis and associated healthcare-seeking behaviours in northern Côte d’Ivoire and southern Mauritania

Background:Among parasitic infections,schistosomiasis ranks second after malaria in terms of worldwide morbidity.Despite efforts to contain transmission,more than 230 million people are infected,of which 85%live in Sub-Saharan Africa.While the epidemiologic characteristics of schistosomiasis have been extensively studied across endemic settings,social factors have been paid less attention.The current study assesses community knowledge of schistosomiasis causes,transmission,signs,symptoms and prevention,as well as healthcare-seeking behaviours in two West African settings,with the aim of strengthening schistosomiasis control interventions.Methods:From August 2014 to June 2015,we conducted two cross-sectional surveys in Korhogo,Cote d’Ivoire and Kaedi,Mauritania.We applied a questionnaire to collect quantitative data at the household level in Korhogo(n=1456)and Kaedi(n=1453).Focus group discussions(Korhogo:n=32,Kaedi:n=32)and participatory photography(photovoice)(Korhogo:n=16,Kaedi:n=16)were conducted within the communities to gather qualitative data.In addition,semi-structured interviews were used to discuss with key informants from control programmes,nongovernmental organizations and health districts(Korhogo:n=8,Kaedi:n=7).Results:The study demonstrated that schistosomiasis is not well known by the communities;64.1%claimed to know the causes of the disease,but the reality is different.This knowledge is more from cultural than biomedical source.It was observed that social construction of the disease is different from the biomedical definition.In Korhogo,schistosomiasis was often associated with several other diseases,notably stomach ulcer and gonorrhoea.The populations believe that schistosomiasis is caused by exposure to goat or dog urine in the environment.In Kaedi,schistosomiasis is considered as a disease transmitted by environmenal elements such as sunshine and dirty water.In both settings,the care-seeking pathways were found to be strongly influenced by local customs and self-medication acquired from the informal sector.Conclusions:This study revealed that knowledge about the aetiology,transmission,symptoms,prevention and treatment of schistosomiasis among the populations in Korhogo and Kaedi is based on their local culture.Deep-rooted habits could therefore pose a significant obstacle to the elimination of schistosomiasis.

Correction to:Community knowledge,attitudes and practices related to schistosomiasis and associated healthcareseeking behaviours in northern Côte d’Ivoire and southern Mauritania

Correction After publication of this article[1]it came to our attention that Tables 2,3,4,5,6,7 were presented incorrectly.The correct tables can be found below and the table citations in the article were corrected as well.The original article has been updated to reflect this change.

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.

新型冠状病毒引发全球卫生危机,需要科学解决方案和地方行动

根据《国际卫生条例(2005)》(IHR),世界卫生组织(WHO)宣布将新型冠状病毒肺炎(COVID-19)列为国际关注的突发公共卫生事件。系统性问题导致此次病毒暴发,该疫情全世界大流行对全球政治和社会系统产生了重大影响。虽然过去15年间科学界在提高了公众对于疾病大流行的警觉方面做了大量的工作,但此次疫情依然暴发并已威胁全球人们的健康,影响经济发展。为了更好地应对这一事件,降低风险,有哪些做法可以改进?对政府、学术组织和个人有哪些科学建议?本文探讨在如何保障人民健康安全的同时,降低经济和社会成本,并号召世界科学家参加"未来地球健康领域知识行动网络"计划。