Identification and Subtyping of Cryptosporidium parvum and Cryptosporidium hominis in Cancer Patients, Isfahan Province, Central Iran

Background: Cryptosporidium spp. are protozoan parasites that cause diarrhea in humans and animals. Subtyping data about Cryptosporidium spp. in Isfahan, Iran is limited; therefore, we aimed to study the prevalence rate of Cryptosporidium spp. in cancer patients, associated risk factors, and subtypes of Cryptosporidium spp. 
Methods: Fecal samples were collected from 187 cancer patients from the Oncology Department of Seyed-al-Shohada Hospital, Isfahan University of Medical Sciences during 2014–2020 and screened for Cryptosporidium spp. using microscopical techniques. Nested PCR amplifying 18S rRNA gene was used to detect Cryptosporidium spp. in samples, followed by subtyping using nested PCR amplifying gp60 sequences. 
Results: Overall, the rate of infection with Cryptosporidium spp. was 4.3% (n=8). Five samples out of eight samples were identified as Cryptosporidium spp. using a nested PCR for the 18S rRNA gene, two subtypes of C. parvum named IIaA18G3R1 (n = 2) and IIaA17G2R1 (n = 2), and one subtype of C. hominis named IbA6G3 were identified by sequencing of the gp60. The IbA6G3 subtype has rarely been detected in other investigations. 
Conclusion: This is the first survey on the subtyping of Cryptosporidium spp. in this region. The results of the present survey show both zoonotic and anthroponotic transmission routes in the region.