title: Automated parasite faecal egg counting using fluorescence labelling, smartphone image capture and computational image analysis.
abstract: Intestinal parasites are a concern in veterinary medicine worldwide and for human health in the developing world. Infections are identified by microscopic visualisation of parasite eggs in faeces, which is time-consuming, requires technical expertise and is impractical for use on-site. For these reasons, recommendations for parasite surveillance are not widely adopted and parasite control is based on administration of rote prophylactic treatments with anthelmintic drugs. This approach is known to promote anthelmintic resistance, so there is a pronounced need for a convenient egg counting assay to promote good clinical practice. Using a fluorescent chitin-binding protein, we show that this structural carbohydrate is present and accessible in shells of ova of strongyle, ascarid, trichurid and coccidian parasites. Furthermore, we show that a cellular smartphone can be used as an inexpensive device to image fluorescent eggs and, by harnessing the computational power of the phone, to perform image analysis to count the eggs. Strongyle egg counts generated by the smartphone system had a significant linear correlation with manual McMaster counts (R(2)=0.98), but with a significantly lower coefficient of variation (P=0.0177). Furthermore, the system was capable of differentiating equine strongyle and ascarid eggs similar to the McMaster method, but with significantly lower coefficients of variation (P<0.0001). This demonstrates the feasibility of a simple, automated on-site test to detect and/or enumerate parasite eggs in mammalian faeces without the need for a laboratory microscope, and highlights the potential of smartphones as relatively sophisticated, inexpensive and portable medical diagnostic devices.
authors.affiliation: MEP Equine Solutions, 3905 English Oak Circle, Lexington, KY 40514, USA; M.H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA. Electronic address: pslusarewicz@mepequinesolutions.com.
authors.forename: Paul
authors.initials: P
authors.lastname: Slusarewicz
authors.affiliation: MEP Equine Solutions, 3905 English Oak Circle, Lexington, KY 40514, USA; M.H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Pagano
authors.affiliation: MEP Equine Solutions, 3905 English Oak Circle, Lexington, KY 40514, USA; M.H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Mills
authors.affiliation: Department of Molecular & Cellular Biochemistry, University of Kentucky, Lexington, KY, USA.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Popa
authors.affiliation: Department of Molecular & Cellular Biochemistry, University of Kentucky, Lexington, KY, USA.
authors.forename: K Martin
authors.initials: KM
authors.lastname: Chow
authors.affiliation: Department of Molecular & Cellular Biochemistry, University of Kentucky, Lexington, KY, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Mendenhall
authors.affiliation: Department of Molecular & Cellular Biochemistry, University of Kentucky, Lexington, KY, USA.
authors.forename: David W
authors.initials: DW
authors.lastname: Rodgers
authors.affiliation: M.H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.
authors.forename: Martin K
authors.initials: MK
authors.lastname: Nielsen
mesh_terms: D000818:Animals; D017162:Ascaridida / Q000302:isolation & purification; D002415:Cats; D002417:Cattle; D002686:Chitin / Q000378:metabolism; D004285:Dogs; D005243:Feces / Q000469:parasitology*; D005374:Filtration / Q000295:instrumentation; D005456:Fluorescent Dyes; D006041:Goats; D006736:Horses; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D010270:Parasite Egg Count / Q000295:instrumentation / Q000379:methods*; D012756:Sheep; D000068997:Smartphone; D013320:Strongyloidea / Q000302:isolation & purification
chemical_list: D005456:Fluorescent Dyes; D002686:Chitin
keywords: Ascarid; Chitin; Egg count; Equine; Fluorescence; Image analysis; Smartphone; Strongyle