Techniques of aspiration cytology, biopsy and cell block of the bone marrow for the identification and determination of parasite intensity in Canine Visceral Leishmaniasis

ABSTRACT The aim of the present study was to compare the aspiration cytology, biopsy and cell block techniques for identification and parasitological quantification of Leishmania (Leishmania) infantum chagasi in dog bone marrow. Bone marrow tissue samples from 26 animals, in different clinical-laboratory stages of the disease, were studied according to the same criteria of investigation in the aspiration cytology, biopsy and cell block techniques. The lowest number of fields for the parasitological confirmation was found in the direct smear obtained by aspiration cytology. The clinical-laboratory stage did not influence the number of fields required for the first visualization of the agent in any of the techniques (p> 0.05) and less parasitic intensity was observed in the cell block slides. The aspiration cytology and biopsy techniques agreed on the estimation of infectivity coefficient in the tissue studied (p< 0.05). Although the cell block technique allows the concentration of cells and better reutilization of samples, it has not been shown to be an adequate method for rapid identification and parasitological quantification in canine visceral leishmaniasis. Considering its advantages, aspiration cytology was the best method for microscopic detection of the parasite and determination of the level of parasite intensity in the tissue studied.