Aydemir, SelahattinYilmaz, HasanBarlik, Fethi2026-04-022026-04-0220251687-79422090-264610.21608/PUJ.2025.435080.1322https://hdl.handle.net/123456789/30074https://doi.org/10.21608/PUJ.2025.435080.1322Background: Cryptosporidiosis is an important zoonotic protozoan infection at the human-animal interface, particularly in areas with intensive livestock farming. Data on the molecular epidemiology, and transmission dynamic of cryptosporidiosis at eastern Türkiye are limited. Objective: To determine the prevalent species causing cryptosporidiosis in calves, and humans with diarrhea in Ağrı, Türkiye. Subjects and Methods: The study included 100 stool samples collected from volunteer patients with diarrhea, and 193 calves between February and December 2022. Stool samples were examined using modified acid-fast staining, immunochromatographic (ICT) cassette test, and molecular methods that included sequencing the genes encoding Cryptosporidium oocystwall protein (COWP) for genotyping, and the 60-kDa glycoprotein (gp60) for subtyping the human isolates. Results: Modified acid-fast staining revealed Cryptosporidium oocysts in 52/193 (26.9%) calves' stool samples, and in 5/100 (5%) human stool samples. The ICT card test identified 59/193 (30.6%) positive calves' samples and confirmed all human cases. Nested PCR revealed that all ICT-positive calves and human samples were also positive by COWP sequencing, and were identified as C. parvum. Utilizing gp60 subtyping demonstrated two IId subtypes, IIdA18G1 and IIdA20G1. Abdominal pain and vomiting were the most frequent clinical manifestations among infected patients. Conclusion: Patients with diarrhea and infected with IId subtypes may have acquired cryptosporidiosis directly, or indirectly from infected small ruminants or calves. This issue raises public health concerns in terms of cryptosporidiosis in Türkiye eastern region, where animal husbandry is intensively practiced.eninfo:eu-repo/semantics/openAccessGp60GenotypingTürkiyeCOWPC. ParvumHumanCalvesArticle