Prevalence, species distribution, and parasitic burden of Cryptosporidium infection in cancer patients: A case-control study in Egypt

Cryptosporidiosis causes a significant impact on immunocompromised patients, but its epidemiology among Egyptian cancer patients is poorly studied. This study was conducted to evaluate the prevalence, species distribution, and Cryptosporidium DNA copy number among Egyptian cancer patients versus immunocompetent controls. This case-control study included 600 cancer patients and 400 immunocompetent controls. In addition to modified acid-fast staining, molecular analysis was performed using eight new, in silico and in vitro validated species-specific primer sets targeting Cryptosporidium parvum, Cryptosporidium hominis, Cryptosporidium meleagridis, Cryptosporidium muris, Cryptosporidium canis, Cryptosporidium felis, Cryptosporidium ubiquitum, and Cryptosporidium chipmunk, using a qPCR-based standard curve. Cryptosporidium infection was found in 37.0% of cancer patients compared to 11.8% of controls (p< 0.0001). C. parvum was more prevalent among the cancer patients (62.5%) than among controls (46.8%, p= 0.009), whereas C. muris was more prevalent among controls (10.6% vs. 1.5%, p= 0.008). qPCR analysis indicated significant differences in Cryptosporidium DNA copy number (copies/µL) of C. parvum and C. hominis (p< 0.05). Species distribution varied significantly with cancer type (p< 0.001); C. parvum was present only in acute lymphocytic leukemia (ALL), gastric adenocarcinoma, colorectal, and liver cancers, whereas C. hominis was found in acute myeloid leukemia (AML). C. meleagridis and C. muris were identified in patients with acute lymphocytic leukemia and colon cancer. Our results showed a significantly higher prevalence of the parasite in cancer patients, with a notable difference in the distribution of species depending on the type of malignancy and clinical relevance for targeted screening.