In another study reporting molecular characterization of Cryptosporidium isolated from humans and animals in Iran, Meamar et al. identified Cryptosporidium in 8 out of 15 isolates from AIDS patients, seven of which they identified as C.parvum and one as C.hominis (18). Berenji et al. conducted a study in pediatric patients with lymphatic and hematological malignancies in Mashhad (center of Khorasan Razavi province, north-west Iran)
hospitals and detected 22%Cryptosporidium infections overall, with a prevalence of 19% in patients with ALL, 2% with AML and 1% with NHL (16). In a case-control study, Sharif et al. identified 5%Cryptosporidium buy Erlotinib infections overall, including in 3% of patients with ALL, 1%
of those who had received bone marrow transplants and 1% with find more NHL (17). Using 18s rRNA gene amplification and sequencing, Meamar et al. evaluated the prevalence of Cryptosporidium genotypes in HIV-positive and -negative patients and identified that 88.9% of HIV infected individuals were infected with C. parvum and 11.9% with C. hominis, whereas in HIV negative patients 62.5% were infected with C. parvum and 37.5% with C. hominis (18). Thus, the reported prevalence of Cryptosporidium infection in Iranian immunocompromised patients ranges between 1.5% and 22% with a mean of 7%. It is well documented that, in the Middle East, C. parvum is the dominant species both in immunocompetent and immunocompromised individuals (15, 19, 20). In the present study, we found no sex difference in the frequency
of cryptosporidiosis. However, patients older than 30 years had a higher risk of this infection. Similar age related increases in Cryptosporidium infection have previously been reported (21), but this may be because Ribonucleotide reductase there are few immunocompromised patients younger than 30 years. In relation to the clinical features of Cryptosporidium infection, we found that diarrhea, weight loss, abdominal pain, dehydration, vomiting and nausea were significantly associated with Cryptosporidium infection. Manabe et al. and a review by Hunter et al. have also reported a high prevalence of these clinical symptoms (4, 22). In some studies, C. hominis was associated with diarrhea, nausea, vomiting and general malaise, whereas C. parvum and other species were associated with diarrhea only (7). However, in the present study we found no differences between Cryptosporidium genotypes in severity of clinical manifestations, which is possibly because all study patients were immunosuppressed. Other microbial infections occurred more frequently in Cryptosporidium infected patients, particularly in those with HIV. Immune-suppression, especially when advanced, is a major risk factor for existence of co-pathogens in these individuals (4, 22).