Investigação da sensibilidade analítica dos testes de detecção de sangue oculto fecal baseados nos reagentes guaiac e benzidina em cães

• Autor(a) principal: Silva, Geovana Alves Justino
• Data de Publicação: 2020
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UFU
• Texto Completo: https://repositorio.ufu.br/handle/123456789/30923
• topic: amostra fecal, canino, sangramento gastrointestinal oculto, testes rápidos; CNPQ::CIENCIAS AGRARIAS

Fecal occult blood tests available for use in animals, whose methodologies are based on Benzidine and Guaiac reagents, are tests that detect in a nonspecific and subjective manner the presence of hemoglobin in fecal samples, whose sensitivity varies significantly between studies previously conducted. Thus, the present study aimed to investigate the analytical sensitivity of fecal occult blood detection tests based on Guaiac (gTSOF) and Benzidine (bTSOF) reagents in canine fecal samples. Six healthy dogs were selected, whose feces collected by spontaneous defecation were laboratoryally prepared to contain 1, 5, 10, 20 and 40 μg of hemoglobin/g of feces and tested for fecal occult blood by both tests. The reading of the tests was photographed and analyzed by double-blind metodology by 3 clinical pathologists. The results were analyzed based on two classifications, by positivity, meaning, "absence vs. presence" of occult blood in the feces (scores 0 and 1, respectively) and by intensity, in which we used "absence vs. intensity of weak, moderately and positive fecal occult bleeding" (scores 0, 1, 2 and 3, respectively). It was concluded that the bTSOF and gTSOF tests were able to decode blood concentrations from 1 μg Hb/g feces and that, although the Benzidine reagent presented good analytical sensitivity for detection of occult blood in the feces of domestic dogs, gTSOF presented better individual performance in all analyzed questions, including sensitivity and practicality in the performance of the test. The reagents tested were able to dece rate blood concentrations from 1 μg Hb/g of feces and 100% of the samples with no blood, with a significant predominance of moderate classification by the test using guaiac (76%) and strong (74%), by the test used benzidine (p<0.0001). When the different concentrations were evaluated, the moderate intensity classification (>50%) was observed, and that no sample containing 40 mgHb/g of feces obtained a negative or weakly positive classification (p<0.0001). The gTSOF presented superior performance to bTSOF in the issues sensitivity, positive and negative predictive values, positive and negative likelihood ratios and accuracy. Keywords: fecal sample, canine, occult gastrointestinal bleeding, quick tests.