BackgroundLarge scale administration of the anthelminthic drug praziquantel (PZQ) to at-risk populations is the cornerstone of schistosomiasis control, although persisting high prevalence of... Show moreBackgroundLarge scale administration of the anthelminthic drug praziquantel (PZQ) to at-risk populations is the cornerstone of schistosomiasis control, although persisting high prevalence of infections in some areas and growing concerns of PZQ resistance have revealed the limitations of this strategy. Most studies assessing PZQ efficacy have used relatively insensitive parasitological diagnostics, such as the Kato-Katz (KK) and urine-filtration methods, thereby overestimating cure rates (CRs). This study aims to determine the efficacy of repeated PZQ treatments against Schistosoma mansoni infection in school-aged children in Cote d'Ivoire using the traditional KK technique, as well as more sensitive antigen- and DNA-detection methods.MethodsAn open-label, randomised controlled trial will be conducted in school-aged children (5 to 18years) from the region of Taabo, Cote d'Ivoire, an area endemic for S. mansoni. This 8-week trial includes four two-weekly standard doses of PZQ in the intense treatment intervention group and one standard dose of PZQ in the standard treatment control group. The efficacy of PZQ will be evaluated in stool samples using the KK technique and real-time PCR as well as in urine using the point-of-care circulating cathodic antigen test and the up-converting phosphor, lateral flow, circulating anodic antigen assay. The primary outcome of the study will be the difference in CR of intense versus standard treatment with PZQ on individuals with a confirmed S. mansoni infection measured by KK. Secondary outcomes include the difference in CR and intensity reduction rate between the intense and standard treatment groups as measured by the other diagnostic tests, as well as the accuracy of the different diagnostic tests, and the safety of PZQ.DiscussionThis study will provide data on the efficacy of repeated PZQ treatment on the clearance of S. mansoni as measured by several diagnostic techniques. These findings will inform future mass drug administration policy and shed light on position of novel diagnostic tools to evaluate schistosomiasis control strategies.Trial registrationThe study is registered at EudraCT (2016-003017-10, date of registration: 22 July 2016) and (NCT02868385, date of registration: 16 August 2016). Show less
Hoekstra, P.T.; Partal, M.C.; Amoah, A.S.; Lieshout, L. van; Corstjens, P.L.A.M.; Tsonaka, S.; ... ; Dam, G.J. van 2018
Human schistosomiasis (bilharzia) is one of the major parasitic diseases in the world, affecting 200 million people predominantly in third world countries. In areas where the disease is highly... Show moreHuman schistosomiasis (bilharzia) is one of the major parasitic diseases in the world, affecting 200 million people predominantly in third world countries. In areas where the disease is highly prevalent it causes important health problems, and it also has socially-economic effects on the population. Schistosomiasis is caused by the presence of the blood-fluke Schistosoma in the blood-vessels of mammalian hosts. The current method for diagnosis of schistosomiasis in developing countries is the parasitological examination of urine and faeces for the presence of Schistosoma eggs. An alternative method which is now increasingly used is based on the detection of Schistosoma antigens in the circulatory system or the urine of the host. The gut of the parasite is an important source of these antigens since many gut-associated antigens are excreted into the circulation of the host following digestion of food (e.g. blood cells, proteins) by the parasite. Two major gut–associated antigens which have been thoroughly studied with regard to diagnostic detectability, are the circulating anodic antigen (CAA) and the circulating cathodic antigen (CCA). In this thesis, these two unique antigens are further analysed with respect to their biochemical carbohydrate structure, localization, in vitro and in vivo excretion and detection patterns, and their role in a number of host-parasite immune interactions (granulocytes, complement system). Show less
