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Table 3 Advantages and disadvantages of common diagnostic methods for the detection of L. infantum infection in dogs.

From: LeishVet guidelines for the practical management of canine leishmaniosis

DIAGNOSTIC TECHNIQUES ADVANTAGES DISADVANTAGES
SEROLOGY • Determination of antibody level which is essential for the diagnosis and establishing a prognosis • Does not detect the actual presence of the Leishmania parasite
• Serocrossreactions with trypanosomes
QUALITATIVE • Rapid in-clinic test • Provides only positive or negative result
• Variable sensitivities and performance with risk of false negatives
• A positive result needs to be further evaluated by a quantitative serology
QUANTITATIVE
(IFAT, ELISA)
Determines the antibody level
• High antibodies levels in the presence of compatible clinical signs and/or clinicopathological abnormalities are conclusive of clinical leishmaniosis
• Performance and accuracy of cut-off will depend on the laboratory
• Differences between laboratories and poor standardization of techniques
• Low antibody levels will require further work-up
CYTOLOGY/HISTOPATHOLOGY Permits direct detection of the parasite itself and the type of pathological findings:
- Pathological findings suspicious of infection
- Allows exclusion of other differential diagnoses
- Rapid and non invasive (cytology)
• Low sensitivity for the detection of Leishmania amastigotes in tissues or body fluids
• Requires the performance of other diagnostic tests such as immunohistochemistry and/or PCR when parasites are not visualized
• Does not reveal the immunological status of the dog
• Needs expertise
PCR • Allows the detection of leishmanial DNA
• High sensitivity (kDNA) and specificity
• Parasitic load quantification (if Real time-PCR)
• False positive results possible due to DNA contamination
• Different standardization and techniques used by different diagnostic laboratories
• Does not reveal immunological status
• It cannot be performed as the sole diagnostic technique for the confirmation of the disease because a positive result confirms Leishmania infection but not disease
PARASITE CULTURE • Permits the isolation of Leishmania parasites
• Facilitates the isoenzymatic identification of the parasite
• Time-consuming and laborious diagnostic technique
• It can require one month to provide a result
• Performed only in research laboratories