ABSTRACT
In this study, we aimed to introduce a new technique called TF-Test Modified/Dog for the diagnosis of gastrointestinal parasites in dogs. Fecal samples from 106 dogs were processed by the technique TF-Test Modified/Dog and the techniques of centrifugation-flotation in zinc sulfate, simple-flotation by saturated solution of sodium chloride, direct microscopy exam and TF-Test Conventional. Sensitivity was higher in the TF-Test Modified/Dog (98.41%), followed by flotation in saturated zinc sulfate (77.78%), TF-Test Conventional (73.02%), flotation by saturated sodium chloride (55.55%), and direct microscopy exam (30.16%). The diagnostic efficiency varied from 58.49% to 99.06%, with the highest value also obtained by the new proposed technique. Efficiency level of 99.06% with kappa index 0.979 (almost perfect) was obtained with the TF-Test Modified/Dog. These results represent significant statistical gains (P < 0.05) of 20.63% in sensitivity and 12.27% in efficiency over the best among the other techniques flotation by saturated zinc sulfate, whose kappa index was 0.738, much lower than that of the TF-Test Modified/Dog. All techniques presented 100% specificity. In this sense, the high sensitivity of the TF-Test Modified/Dog makes it suitable for epidemiological surveys of gastrointestinal parasitosis in dogs, zoonoses control and preventive surveillance programs.
O objetivo deste estudo foi introduzir a nova técnica TF-Test Modified/Dog para diagnóstico de parasitos gastrointestinais em cães. Amostras fecais de 106 cães foram processadas pela técnica de TF-Test Modified/Dog e também por técnicas de centrifugação-flutuação em sulfato de zinco, flutuação simples em solução saturada de cloreto de sódio, exame microscópico direto e TF-Test Convencional. A sensibilidade foi maior no TF-Test Modified/Dog (98,41%), seguido por centrífugo-flutuação em solução de sulfato de zinco (77,78%), TF-Test Convencional (73,02%), flutuação em solução saturada de cloreto de sódio (55,55%), e exame microscópico direto (30,16%). A eficiência diagnóstica variou de 58,49% a 99,06%, com maior valor obtido pela nova técnica. Foi obtido com o TF-Test Modified/Dog eficiência de 99,06%, com índice kappa de 0,979 (Quase perfeito). Estes resultados representam ganhos estatisticamente significativos (P < 0,05) de 20,63% de sensibilidade e 12,27% de eficiência sobre a melhor entre as outras técnicas empregadas, centrífugo-flutuação em solução de sulfato de zinco, cujo índice kappa foi 0,738, bem menor do que o TF-Test Modified/Dog. Todas as técnicas apresentaram especificidade de 100%. Nesse sentido, a sua alta sensibilidade o torna adequado para levantamentos epidemiológicos das parasitoses gastrointestinais em cães, bem como para programas de controle de zoonoses e de vigilância preventiva.
Subject(s)
Animals , Dogs , Clinical Laboratory Techniques , Dog Diseases/diagnosis , Dog Diseases/parasitology , Intestinal Diseases, Parasitic/veterinary , Feces/parasitology , Intestinal Diseases, Parasitic/diagnosisABSTRACT
This study compares the diagnostic accuracy of the TF-Test® (TFT) for human parasitosis with results obtained using the traditional Kato-Katz (KK), Hoffman-Pons-Janer (HPJ), Willis and Baermann-Moraes (BM) techniques. Overall, four stool samples were taken from each individual; three alternate-day TFT stool samples and another sample that was collected in a universal container. Stool samples were taken from 331 inhabitants of the community of Quilombola Santa Cruz. The gold standard (GS) for protozoa detection was defined as the combined results for TFT, HPJ and Willis coproscopic techniques; for helminth detection, GS was defined as the combined results for all five coproscopic techniques (TFT, KK, HPJ, Willis and BM). The positivity rate of each method was compared using the McNemar test. While the TFT exhibited similar positivity rates to the GS for Entamoeba histolytica/dispar (82.4 percent) and Giardia duodenalis (90 percent), HPJ and Willis techniques exhibited significantly lower positivity rates for these protozoa. All tests exhibited significantly lower positivity rates compared with GS for the diagnosis of helminths. The KK technique had the highest positivity rate for diagnosing Schistosoma mansoni (74.6 percent), while the TFT had the highest positivity rates for Ascaris lumbricoides (58.1 percent) and hookworm (75 percent); HPJ technique had the highest positivity rate for Strongyloides stercoralis (50 percent). Although a combination of tests is the most accurate method for the diagnosis of enteral parasites, the TFT reliably estimates the prevalence of protozoa and selected helminths, such as A. lumbricoides and hookworm. Further studies are needed to evaluate the detection accuracy of the TFT in samples with varying numbers of parasites.