title: A novel procedure for precise quantification of Schistosoma japonicum eggs in bovine feces.
abstract: Schistosomiasis japonica is a zoonosis with a number of mammalian species acting as reservoir hosts, including water buffaloes which can contribute up to 75% to human transmission in the People's Republic of China. Determining prevalence and intensity of Schistosoma japonicum in mammalian hosts is important for calculating transmission rates and determining environmental contamination. A new procedure, the formalin-ethyl acetate sedimentation-digestion (FEA-SD) technique, for increased visualization of S. japonicum eggs in bovine feces, is described that is an effective technique for identifying and quantifying S. japonicum eggs in fecal samples from naturally infected Chinese water buffaloes and from carabao (water buffalo) in the Philippines. The procedure involves filtration, sedimentation, potassium hydroxide digestion and centrifugation steps prior to microscopy. Bulk debris, including the dense cellulosic material present in bovine feces, often obscures schistosome eggs with the result that prevalence and infection intensity based on direct visualization cannot be made accurately. This technique removes nearly 70% of debris from the fecal samples and renders the remaining debris translucent. It allows improved microscopic visualization of S. japonicum eggs and provides an accurate quantitative method for the estimation of infection in bovines and other ruminant reservoir hosts. We show that the FEA-SD technique could be of considerable value if applied as a surveillance tool for animal reservoirs of S. japonicum, particularly in areas with low to high infection intensity, or where, following control efforts, there is suspected elimination of schistosomiasis japonica.
authors.affiliation: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Gordon
authors.forename: Wei
authors.initials: W
authors.lastname: Hu
authors.forename: Donald P
authors.initials: DP
authors.lastname: McManus
authors.forename: Hong-Gen
authors.initials: HG
authors.lastname: Chen
authors.forename: Darren J
authors.initials: DJ
authors.lastname: Gray
authors.forename: Chuan
authors.initials: C
authors.lastname: Ju
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Zeng
authors.forename: Geoffrey N
authors.initials: GN
authors.lastname: Gobert
authors.forename: Jun
authors.initials: J
authors.lastname: Ge
authors.forename: Wei-Ming
authors.initials: WM
authors.lastname: Lan
authors.forename: Shu-Ying
authors.initials: SY
authors.lastname: Xie
authors.forename: Wei-Sheng
authors.initials: WS
authors.lastname: Jiang
authors.forename: Allen G
authors.initials: AG
authors.lastname: Ross
authors.forename: Luz P
authors.initials: LP
authors.lastname: Acosta
authors.forename: Remigio
authors.initials: R
authors.lastname: Olveda
authors.forename: Zheng
authors.initials: Z
authors.lastname: Feng
mesh_terms: D000818:Animals; D002020:Buffaloes; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology*; D002681:China; D005243:Feces / Q000469:parasitology*; D010270:Parasite Egg Count / Q000379:methods*; D010679:Philippines; D012549:Schistosoma japonicum / Q000302:isolation & purification*; D012554:Schistosomiasis japonica / Q000469:parasitology / Q000662:veterinary*