[Evaluation of usefulness of different methods for detection of Cryptosporidium in human and animal stool samples]

There are many methods for detection of Cryptosporidium oocysts. Most of them (more than 20) enable the microscopic detection of Cryptosporidium oocysts in faecal smears. Such a great variability of diagnostic methods may lead to confusion as far as the choice of an appropriate technique by a given laboratory is concerned. This study evaluated the diagnostic usefulness of Cryptosporidium oocysts and coproantigen detection methods in the diagnosis of cryptosporidiosis in human (266 stool specimen) and animals (205 from cattle, 160 from sheep, 30 from horses, 80 from cats, 227 from dogs and 11 from wild animals). The total number of human and animal stool specimens processed was 266 and 713, respectively. In this study the usefulness of several diagnostic methods was compared. The following techniques were taken into account: wet mounts, hematoxylin staining, four different specific methods (modified Zeihl-Neelsen, Kinyoun's, safranin-methylene blue, as well as carbol-methyl violet and tartrazyne) and commercially available kit based on enzyme-linked immunoassay (ProspecT(r) Cryptosporidium Microplate Assay). The final number of positive specimens was 123. Out of them 77 were positive in all specific methods. The oocysts found in stool specimens were measured. Humans were infected with C. parvum and animals with C. parvum, C. andersoni or C. felis. The statistical analysis has shown that EIA test was a better than microscopy method for identification of Cryptosporidium in faecal samples in human and wild animal. Sensitivity and specificity are important factors for the choice of a proper diagnostic method for Cryptosporidium detection, however other factors such as cost, simplicity and ease of interpretation of results are also important considerations.