EDTA as a potential obstacle to the detection of trypanosomes in anuran blood samples using Woo's technique

Anurans have long served as hosts for Trypanosoma species, playing a foundational role in the study of these hemoflagellates in parasitology. Woo's technique provides a practical and straightforward method for screening trypanosomatids. This study evaluates the suitability of ethylenediaminetetraacetic acid (EDTA) as an anticoagulant for performing Woo's technique in the detection of anuran trypanosomes and describes associated morphological changes. Sixteen blood samples from Leptodactylus luctator frogs were collected in EDTA-K2 microtubes and compared with eleven lithium heparinized samples. Woo's technique was applied, and morphological analyses were conducted on both fresh and anticoagulated blood smears. The results showed a higher detection rate of trypanosomes in heparinized samples compared to those treated with EDTA. Morphological alterations were observed in EDTA-anticoagulated smears, suggesting an effect on parasite viability that may impair their mobility during capillary tube examination. These findings indicate that lithium heparin may be more suitable than EDTA for applying Woo's technique to anuran blood samples.