Abstract
ABSTRACT. Muniz Neta E. de S., Sampaio D.C., Galvão G. da S. & Munhoz A.D. [Comparison between the modified Ziehl-Neelsen technique and the phase contrast for detection of oocysts of the genus Cryptosporidium Tyzzer, 1907 (Apicomplexa: Cryptosporidiidae) in assintomatic cattle.] Comparação das técnicas de Ziehl-Neelsen modificada e contraste de fase na detecção de oocistos do gênero Cryptosporidium Tyzzer, 1907 (Apicomplexa: Cryptosporidiidae) em bovinos assintomá- ticos. Revista Brasileira de Medicina Veterinária, 32(4):201-204,2010. Laboratório de Análises Clínicas Veterinárias, Departamento de Ciências Agrárias e Ambientais, Universidade Estadual de Santa Cruz, Rodovia Ilhéus-Itabuna, Km 16, Salobrinho, Ilhéus, BA 45650-000, Brasil. E-mail: munhoz@uesc.br The aim of this study was to compare the modified Ziehl-Neelsen Technique (ZNM) and the centrifugal-flotation with phase contrast (CF) for detection of oocysts of Cryptosporidium in asymptomatic cattle. One hundred fifty-six fecal samples of asymptomatic cattle (64 calves and 92 adults) were collected and selected using not random method. For the ZNM technique was prepared three slides of each sample. To the statistical analysis was used the Cohen’s Kappa statistics for comparison of the techniques and the chi-square test with Yates correction to evaluate the use of more than one slide in the ZNM technique. It was observed a poor agreement (k: 0.08) between the CF, with either one or three slides in the ZNM, in which results showed that the first comparison of the simultaneous need of techniques to increase the detection of positive animals and second comparison that the sensitivity of the three slides was superior to the CF. This can be verified when just one slide was examined, showing that 41(26.3%) of all animals would not be diagnosed with Cryptosporidium, accounting for 46.06% of positive (p<0.001), underestimating the occurrence of this coccidian. Thus the reading of three blades became more sensitive diagnosis of Cryptosporidium and should be recommended mainly in asymptomatic animal studies of which could minimize the number of false negatives.