What is the preferred method for diagnosing cryptosporidiosis in sheep - Modified Ziehl–Neelsen or auramine O staining?

Cryptosporidium is an intestinal apicomplexan protozoon that causes cryptosporidiosis, a diarrheal disease affecting gastrointestinal tract of a wide range of vertebrates, including humans, livestock, wild animals, and birds. In the present study, Cryptosporidium spp. infection was diagnosed in sheep using two staining methods: Modified Ziehl–Neelsen (MZN) and auramine O (AO) staining. A total of 260 fecal samples were collected from sheep. All the samples were subjected to the formalin-ether concentration technique. The fecal smears were stained using the MZN (acid-fast stain) and AO (fluorescent stain) staining methods and then observed under a light and a fluorescent microscope, respectively. Cohen's kappa was used to check the significant agreement between the two diagnostic methods. According to the results, there was substantial agreement between the two methods. However, since there are many fluorescent artifacts in sheep feces, the detection rapidity of Cryptosporidium spp. in sheep feces by MZN staining is higher than that of AO staining. Therefore, it is suggested to use MZN staining for diagnosing cryptosporidiosis in sheep flocks.