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Comparative study of parasitological techniques for demonstration of amastigotes and primary isolation of promastigotes in American Cutaneous leishmaniasis

BACKGROUND: PCR is a highly sensitive procedure for the diagnosis of LTA, but it is expensive and not readily available. Culture and smearing are practical, but they lack sensitivity. OBJECTIVE: The objective of this work is to compare the latter two methods in order to achieve a higher sensitivity at a lower cost. METHOD: Three culture media were compared in the process of isolating leishmaniasis: blood Agar Difco + Schneider + 20% fetal calf serum; Difco + Schneider + human sterile urine (2%); Schneider with sterile human urine (2%). Moreover, two techniques were compared for the demonstration of amastigotes: biopsy performed with smears, or matchstick scrapping RESULTS: The positivity and contamination indices (29-to-33% and 8-to-11%, respectively, p>0.05) were similar when comparing the cultures. The smears carried out by biopsy or the matchstick scrapping procedure had no significant differences (14 and 19%, respectively, p>0.05). Leishmania (Viannia) braziliensis predominated. CONCLUSION: In Brazil, urine may substitute fetal calf serum. The cost-to-benefit ratio is advantageous. Urine has no cost, while the market value of 500 ml of fetal calf serum is $US 185.

Diagnosis; Leishmania braziliensis; Leishmaniasis; cutaneous


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