title: A novel duplex ddPCR assay for the diagnosis of schistosomiasis japonica: proof of concept in an experimental mouse model.
abstract: The current World Health Organization strategic plan targets the elimination of schistosomiasis as a public health problem by 2025 and accurate diagnostics will play a pivotal role in achieving this goal. DNA-based detection methods provide a viable alternative to some of the commonly used tests, notably microscopy and serology, for the diagnosis of schistosomiasis. The detection of parasite cell-free DNA in different clinical samples is a recent valuable advance, which provides significant benefits for accurate disease diagnosis. Here we validated a novel duplex droplet digital PCR assay for the diagnosis of Chinese (SjC) and Philippine (SjP) strains of Schistosoma japonicum infection in a mouse model. The assay proved applicable for both SjC and SjP infections and capable of detecting infection at a very early intra-mammalian stage in conveniently obtainable samples (urine and saliva) as well as in serum and feces. The target DNA copy numbers obtained in the assay showed a positive correlation with the infection burden assessed by direct traditional parasitology. The potential to detect parasite DNA in urine and saliva has important practical implications for large-scale epidemiological screening programmes in the future, particularly in terms of logistical convenience, and the assay has the potential to be a valuable additional tool for the diagnosis of schistosomiasis japonica.
authors.affiliation: Molecular Parasitology Laboratory,QIMR Berghofer Medical Research Institute,Brisbane,Australia.
authors.forename: Kosala G
authors.initials: KG
authors.lastname: Weerakoon
authors.affiliation: Molecular Parasitology Laboratory,QIMR Berghofer Medical Research Institute,Brisbane,Australia.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Gordon
authors.affiliation: Molecular Parasitology Laboratory,QIMR Berghofer Medical Research Institute,Brisbane,Australia.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Cai
authors.affiliation: Molecular Parasitology Laboratory,QIMR Berghofer Medical Research Institute,Brisbane,Australia.
authors.forename: Geoffrey N
authors.initials: GN
authors.lastname: Gobert
authors.affiliation: Molecular Parasitology Laboratory,QIMR Berghofer Medical Research Institute,Brisbane,Australia.
authors.forename: Mary
authors.initials: M
authors.lastname: Duke
authors.affiliation: School of Public Health,University of Queensland,Brisbane,Australia.
authors.forename: Gail M
authors.initials: GM
authors.lastname: Williams
authors.affiliation: Molecular Parasitology Laboratory,QIMR Berghofer Medical Research Institute,Brisbane,Australia.
authors.forename: Donald P
authors.initials: DP
authors.lastname: McManus
mesh_terms: D000818:Animals; D001769:Blood / Q000469:parasitology; D002681:China; D056915:DNA Copy Number Variations; D018509:DNA, Helminth / Q000032:analysis*; D004195:Disease Models, Animal; D005243:Feces / Q000469:parasitology; D005260:Female; D006801:Humans; D051379:Mice; D010679:Philippines; D016133:Polymerase Chain Reaction / Q000379:methods*; D012463:Saliva / Q000469:parasitology; D012549:Schistosoma japonicum / Q000302:isolation & purification*; D012554:Schistosomiasis japonica / Q000175:diagnosis* / Q000469:parasitology; D012680:Sensitivity and Specificity; D014556:Urine / Q000469:parasitology
chemical_list: D018509:DNA, Helminth
keywords: 
                 Schistosoma japonicum
              ; Schistosomiasis; diagnosis; droplet digital PCR; mouse model