Course of experimental infection of canine leishmaniosis: follow-up and utility of noninvasive diagnostic techniques

Vet Parasitol. 2015 Jan 15;207(1-2):149-55. doi: 10.1016/j.vetpar.2014.10.035.

Abstract

This study compares the utility of a molecular diagnosis of experimental CanL on non-invasive samples (urine, conjunctival (CS), oral (OS) and vulvar (VS) swabs) with that of traditional invasive techniques during the course of infection. Eight dogs were experimen-tally infected with Leishmania infantum and followed monthly for 12 months to assess clinical, clinicopathological, immunological and parasitological variables. Active infection was produced in 100% of the dogs. The animals showed positive bone marrow (BM) cytologies and cultures, clinical signs, clinicopathological abnormalities and a high specific humoral immune response. The infection was detected at 90 days post-infection (p.i.) by real-time quantitative PCR (rtQ-PCR) on BM in all dogs and in blood in 2 dogs, while anti-L. infantum antibody seroconversion occurred between Days 120 and 180 days p.i. The tissue with the highest L. infantum kDNA load, as detected by rtQ-PCR, was BM (range 381.5–70,000 parasites/ml at the study end), this sample type showing greater sensitivity than peripheral blood (PB). The vulvar swabs used here for the first time to quantify para-site loads in dogs revealed a greater load than oral and conjunctival swabs at one year p.i. Urine samples showed the lowest concentrations of L. infantum DNA (maximum: 8.57 par-asites/ml). Our results suggest that for the early detection of infection, adding to serology a test such as rtQ-PCR on OS or VS improves sensitivity and specificity.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Bone Marrow / parasitology
  • DNA, Protozoan / genetics
  • DNA, Protozoan / urine
  • Dog Diseases / diagnosis*
  • Dog Diseases / parasitology
  • Dogs
  • Female
  • Follow-Up Studies
  • Leishmania infantum / genetics*
  • Leishmania infantum / immunology
  • Leishmania infantum / isolation & purification
  • Leishmaniasis, Visceral / diagnosis
  • Leishmaniasis, Visceral / parasitology
  • Leishmaniasis, Visceral / veterinary*
  • Real-Time Polymerase Chain Reaction / veterinary
  • Sensitivity and Specificity

Substances

  • DNA, Protozoan