title: A Novel Molecular Test to Diagnose Canine Visceral Leishmaniasis at the Point of Care.
abstract: Dogs are the principal reservoir hosts of zoonotic visceral leishmaniasis (VL) but current serological methods are not sensitive enough to detect all subclinically infected animals, which is crucial to VL control programs. Polymerase chain reaction (PCR) methods have greater sensitivity but require expensive equipment and trained personnel, impairing its implementation in endemic areas. We developed a diagnostic test that uses isothermal recombinase polymerase amplification (RPA) to detect Leishmania infantum. This method was coupled with lateral flow (LF) reading with the naked eye to be adapted as a point-of-care test. The L. infantum RPA-LF had an analytical sensitivity similar to real time-PCR, detecting DNA of 0.1 parasites spiked in dog blood, which was equivalent to 40 parasites/mL. There was no cross amplification with dog or human DNA or with Leishmania braziliensis, Leishmania amazonensis, or Trypanosoma cruzi. The test also amplified Leishmania donovani strains (N = 7). In a group of clinically normal dogs (N = 30), RPA-LF detected more subclinical infections than rK39 strip test, a standard serological method (50% versus 13.3% positivity, respectively; P = 0.005). Also, RPA-LF detected L. infantum in noninvasive mucosal samples of dogs with a sensitivity comparable to blood samples. This novel molecular test may have a positive impact in leishmaniasis control programs.
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Castellanos-Gonzalez
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas.
authors.forename: Omar A
authors.initials: OA
authors.lastname: Saldarriaga
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas.
authors.forename: Lilian
authors.initials: L
authors.lastname: Tartaglino
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas.
authors.forename: Rosana
authors.initials: R
authors.lastname: Gacek
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas.
authors.forename: Elissa
authors.initials: E
authors.lastname: Temple
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas.
authors.forename: Hayley
authors.initials: H
authors.lastname: Sparks
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Melby
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas brltravi@utmb.edu.
authors.forename: Bruno L
authors.initials: BL
authors.lastname: Travi
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000302:isolation & purification; D001118:Argentina / Q000453:epidemiology; D018105:DNA, Kinetoplast / Q000235:genetics / Q000302:isolation & purification*; D004283:Dog Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000469:parasitology*; D004285:Dogs; D007891:Leishmania / Q000235:genetics / Q000302:isolation & purification*; D007898:Leishmaniasis, Visceral / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods / Q000662:veterinary*; D019095:Point-of-Care Systems; D015800:Protozoan Proteins / Q000302:isolation & purification; D012680:Sensitivity and Specificity
chemical_list: D000953:Antigens, Protozoan; D018105:DNA, Kinetoplast; D015800:Protozoan Proteins; C079253:K39 antigen, Leishmania