title: Recombinase polymerase amplification-based assay to diagnose Giardia in stool samples.
abstract: Giardia duodenalis is one of the most commonly identified parasites in stool samples. Although relatively easy to treat, giardiasis can be difficult to detect as it presents similar to other diarrheal diseases. Here, we present a recombinase polymerase amplification-based Giardia (RPAG) assay to detect the presence of Giardia in stool samples. The RPAG assay was characterized on the bench top using stool samples spiked with Giardia cysts where it showed a limit-of-detection nearly as low as the gold standard polymerase chain reaction assay. The RPAG assay was then tested in the highlands of Peru on 104 stool samples collected from the surrounding communities where it showed 73% sensitivity and 95% specificity against a polymerase chain reaction and microscopy composite gold standard. Further improvements in clinical sensitivity will be needed for the RPAG assay to have clinical relevance.
authors.affiliation: Rice University, Bioengineering, Houston, Texas; Universidad Peruana Cayetano Heredia, Department of Internal Medicine, Cusco, Peru; University of Texas Medical Branch, Department of Internal Medicine, Galveston, Texas zcrannell@gmail.com.
authors.forename: Zachary Austin
authors.initials: ZA
authors.lastname: Crannell
authors.affiliation: Rice University, Bioengineering, Houston, Texas; Universidad Peruana Cayetano Heredia, Department of Internal Medicine, Cusco, Peru; University of Texas Medical Branch, Department of Internal Medicine, Galveston, Texas.
authors.forename: Miguel Mauricio
authors.initials: MM
authors.lastname: Cabada
authors.affiliation: Rice University, Bioengineering, Houston, Texas; Universidad Peruana Cayetano Heredia, Department of Internal Medicine, Cusco, Peru; University of Texas Medical Branch, Department of Internal Medicine, Galveston, Texas.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Castellanos-Gonzalez
authors.affiliation: Rice University, Bioengineering, Houston, Texas; Universidad Peruana Cayetano Heredia, Department of Internal Medicine, Cusco, Peru; University of Texas Medical Branch, Department of Internal Medicine, Galveston, Texas.
authors.forename: Ayesha
authors.initials: A
authors.lastname: Irani
authors.affiliation: Rice University, Bioengineering, Houston, Texas; Universidad Peruana Cayetano Heredia, Department of Internal Medicine, Cusco, Peru; University of Texas Medical Branch, Department of Internal Medicine, Galveston, Texas.
authors.forename: Arthur Clinton
authors.initials: AC
authors.lastname: White
authors.affiliation: Rice University, Bioengineering, Houston, Texas; Universidad Peruana Cayetano Heredia, Department of Internal Medicine, Cusco, Peru; University of Texas Medical Branch, Department of Internal Medicine, Galveston, Texas.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Richards-Kortum
mesh_terms: D005243:Feces / Q000469:parasitology*; D016829:Giardia lamblia / Q000302:isolation & purification*; D005873:Giardiasis / Q000175:diagnosis* / Q000453:epidemiology; D006801:Humans; D010568:Peru / Q000453:epidemiology; D016133:Polymerase Chain Reaction / Q000379:methods*; D045522:Recombinases / Q000737:chemistry / Q000378:metabolism*; D012680:Sensitivity and Specificity
chemical_list: D045522:Recombinases