Evaluation of the accuracy of parasitological techniques for the diagnosis of intestinal parasites in cats

Abstract

The accuracy of the parasitological techniques of Willis, Hoffman-Pons-Janer or Lutz (HPLJ), Sheather and Faust was evaluated in fecal samples from stray cats caught by the Zoonosis Control Center in Goiânia, Goiás, Brazil. These four techniques were applied separately to analyze 154 fecal samples, and their accuracy was analyzed based on an evaluation of their sensitivity, specificity, positive and negative predictive values, and Kappa index, resulting in the selection of the Willis technique as the nominal gold standard. Of the 154 samples, 115 (74.68%) tested positive for intestinal parasites. The analysis of the frequency of positivity indicated that the HPLJ technique detected 86.1% of the positive samples and was the closest to the gold standard. The analysis of the accuracy of the techniques was evaluated using the most prevalent parasites. The Sheather technique showed the highest accuracy in the detection of Ancylostomatidae, while the Sheather and HPLJ techniques showed similar accuracies in the detection of Cystoisospora spp. when compared to the gold standard. Lastly, the Faust technique showed the highest accuracy in the detection of Toxoplasma gondii when compared to the gold standard. This study underscores the importance of combining parasitological techniques in the diagnosis of intestinal parasites in cats.Keywords: Accuracy, intestinal parasites, parasitological techniques, stray cats. ResumoA avaliação da acurácia das técnicas parasitológicas de Willis, Hoffman-Pons-Janer ou Lutz (HPJL), Sheather e Faust foram realizadas em amostras fecais de gatos capturados pelo Centro de Controle de Zoonoses em Goiânia, Goiás. Essas quatro técnicas foram utilizadas separadamente para análise de 154 amostras fecais. A análise de acurácia foi empregada, avaliando-se a sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo e índice kappa, sendo a técnica de Willis eleita como padrão-ouro. Das amostras analisadas 74,68% (115/154) foram positivas para enteroparasitos. A análise de frequência de positividade demonstrou que a técnica HPJL detectou 86,1% dos positivos, aproximando-se do padrão-ouro. A avaliação da acurácia foi realizada pela análise dos parasitos mais prevalentes, sendo que, para Ancilostomídeos, a técnica de Sheather apresentou melhor acurácia; para Cystoisospora spp., as técnicas de Sheather e HPJL foram semelhantes e para Toxoplasma gondii, a técnica de Faust apresentou melhor acurácia comparada ao padrão ouro. Este estudo demonstra a importância da associação de técnicas parasitológicas para o diagnóstico de enteroparasitos em gatos.Palavras-chave: Acurácia, enteroparasitos, técnicas parasitológicas, gatos errantes.

Analysis of the accuracy of different laboratory methods for the diagnosis of intestinal parasites from stray and domiciled cats (Felis catus domesticus) in Goiânia, Goiás, Brazil

“…This finding diverges from that reported by Rezende et al (2015) and Ribeiro et al (2015), who recommend associating the Willis technique with the HPJL technique in veterinary clinical and laboratory diagnosis.…”

“…However, their finding is discrepant with the present study, in which the Faust technique was achieved better performance. The inconsistency between the results of the present study and those reported by Rezende et al (2015) can be explained by the fact that the study population was different, since Rezende et al (2015) evaluated only stray cats and the present study analyzed two cat populations: stray and domiciled.…”

“…This is in line with the studies of Táparo et al (2006), who reported the good performance of the Willis technique applied to eggs, cysts and oocysts (REZENDE et al, 2015). The Faust technique obtained a frequency of positivity (74%), while the Sheather technique presented the lowest frequency of positivity (44%).…”

“…Rezende et al's study (REZENDE et al, 2015) demonstrated that the HPJL technique detected more positives, while the Faust technique presented the lowest frequency of positivity. However, their finding is discrepant with the present study, in which the Faust technique was achieved better performance.…”

“…The evaluation of the accuracy of different parasitological techniques allows the determination of concordance and reproducibility for application in veterinary laboratories. Thus the aim of this study was to analyze the accuracy of different laboratory methods for the diagnosis of intestinal parasite from stray and domestic cats and determine the prevalence of the detected parasites (REZENDE et al, 2015;STULL et al, 2015).…”