RESUMO
Introduction: Various stool concentration techniques have been used to increase the microscopic detection of parasites. We assessed the enclosed, single-vial, Mini Parasep® technique in comparison to the currently used coprodiagnosis procedures. Materials and Methods: A total of 150 stool samples were collected. Samples concentrated by formol–ether method (FEM) and Mini Parasep® SF foecal concentrator and unconcentrated samples were subjected to wet mount, iodine mount microscopy and smear examination by modified acid-fast staining. Results: Direct wet mount detected 72 positive samples (48.6%), whereas 77 (51.3%) and 80 (53.3%) samples were detected by FEM and Mini Parasep® SF methods, respectively. The sensitivity of detection of parasites was 98.7%, 95% and 90.1% with Mini Parasep®, FEM and direct microscopy, respectively. A clearer background with less foecal debris and a better yield of Hymenolepis nana, Trichuris trichiura, Entamoeba coli and Giardia lamblia were noted with Mini Parasep®. Conclusion: Mini Parasep® SF technique is simple, rapid and less cumbersome than conventional diagnostics, making it suitable for routine use. In addition, it offers higher sensitivity and better background clearance than both direct stool examination and FEM.
RESUMO
Cryptosporidium es un parásito causante de cryptosporidiosis. Su estadío infectivo, el ooquiste, se elimina con las heces del hospedador, representando los terneros la principal fuente de infección humana. El objetivo de este trabajo fue comparar tres métodos de concentración de heces para recuperar ooquistes de Cryptosporidium. Fueron estudiados un total de 166 terneros. Una única muestra de materia fecal fresca fue analizada por los métodos de Telemann modificado, agua éter, y Tris Tween 80. La identificación de ooquistes fue realizada mediante coloración de Kinyoun modificada. El número de ooquistes concentrados por cada técnica fue cuantificado en 20 campos a 1000X. Del total de muestras analizadas, 22/166 fueron positivas para Cryptosporidium. El número medio de ooquistes recuperados por cada técnica fue: Telemann modificada (124,2±159,5), agua éter (153,0±156,3), tris Tween 80 (92,2±98,3). ANOVA mostró que no existen diferencias significativas entre métodos. De acuerdo con los resultados obtenidos, las tres técnicas pueden ser empleadas para concentrar ooquistes de Cryptosporidium. Si bien los tres métodos presentaron igual sensibilidad y espcificidad, la técnica de agua éter demostró ser sencilla, de bajo costo, y efectiva para recuperar ooquistes, particularmente si se requiere conservar la viabilidad de los mismos.
Cryptosporidium is a parasite which causes cryptosporidiosis. Its infectious stage, the oocyst, is eliminated with the host feces, calves being the main source of human infection. The aim of the present work was to compare three methods of feces concentration to recover Cryptosporidium oocysts. A total of 166 calves were studied. An only sample of fresh feces was analyzed using the following methods: modified Telemann, water ether, and Tris Tween 80. The identification of oocysts was carried out by modified staining Kinyoun technique. The number of concentrated oocysts per technique was quantified in 20 fields at 1000X. From a total of 166 analyzed samples, 22 were Cryptosporidium positive. The average number of recovered oocysts per technique was: modified Telemann (124.2±159.5), water ether (153.0±156.3), Tris Tween 80 (92.2 ± 98.3). ANOVA demonstrated that there are no significant differences between these methods. According to the results obtained, the three techniques may be used to concentrate Cryptosporidium oocysts. Even if there are no differences in sensibility and specificity between these methods, the water ether technique proved to be simple, low-cost, and effective to recover oocysts, particularly if the oocysts condition is to be kept.