title: Canine leishmaniasis: the key points for qPCR result interpretation.
abstract: BACKGROUND
  Diagnosis and follow up of CanL is difficult since the range of clinical signs is varied and seroprevalence is high in endemic areas. The aims of this study were: i) demonstrate the advantages of Leishmania qPCR to diagnose and control CanL and highlight its prognostic value and ii) propose guidelines for tissue selection and infection monitoring.
  
  
  RESULTS
  This study included 710 dogs living in an endemic area of leishmaniasis. Forty percent (285/710) exhibited clinical signs consistent with CanL. Infection was detected in 36.3% (258/710) of the dogs of which 4.5% (32/710) were detected by qPCR, 16.2% (115/710) detected by ELISA and 15.6% (111/710) tested positive for both tests. Only 17.9% (127/710) of the dogs were classified sick (affected) with CanL. All symptomatic dogs with medium or high ELISA titers were qPCR-positive in blood samples. All dogs with inconclusive or low ELISA results with high or medium qPCR parasitemia values developed the disease. Seventy one percent of asymptomatic ELISA-positive dogs confirmed by qPCR (medium to high parasitemia) developed the disease. Bone marrow or lymph node aspirate should be selected to ensure the absence of the parasite in asymptomatic dogs: 100-1,000 parasites/ml in bone marrow are detectable in blood, whereas lower parasite loads are usually negative. Almost 10% of negative samples in blood were positive in conjunctival swabs.
  
  
  CONCLUSIONS
  Because qPCR allows parasite quantification, it is an effective tool to confirm a diagnosis of CanL in (i) cases of inconclusive ELISA results, (ii) when the dog has not yet seroconverted, or (iii) for treatment monitoring.
authors.affiliation: Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain. veronicalucia.martinez@uab.cat
authors.forename: Verónica
authors.initials: V
authors.lastname: Martínez
authors.forename: Javier
authors.initials: J
authors.lastname: Quilez
authors.forename: Armand
authors.initials: A
authors.lastname: Sanchez
authors.forename: Xavier
authors.initials: X
authors.lastname: Roura
authors.forename: Olga
authors.initials: O
authors.lastname: Francino
authors.forename: Laura
authors.initials: L
authors.lastname: Altet
mesh_terms: D000818:Animals; D001769:Blood / Q000469:parasitology; D001853:Bone Marrow / Q000469:parasitology; D003228:Conjunctiva / Q000469:parasitology; D004283:Dog Diseases / Q000175:diagnosis* / Q000469:parasitology*; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D007891:Leishmania / Q000235:genetics / Q000302:isolation & purification*; D007896:Leishmaniasis / Q000175:diagnosis / Q000469:parasitology / Q000662:veterinary*; D008198:Lymph Nodes / Q000469:parasitology; D010274:Parasitology / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*