Both of these hospitals are major central referral centers to which many patients from other areas of Iran are referred. In all, 183 immunocompromised patients were included in this study. Eligibility criteria NVP-BGJ398 were immunosuppression

due to HIV infection (with decreased white cell counts), hematological malignancies and use of immunosuppressive drugs after solid organ transplant or for treatment of chronic or intractable hematologic diseases. The ethics committee of Baqiyatallah University of Medical Sciences approved the study protocol. After informed written consent had been obtained, the study nurse administered a comprehensive questionnaire to each patient. This author-compiled checklist included items on patient variables including age, sex and weight; sociodemographic and intra-familial factors; location of dwelling; occupation; number of household members with diarrhea; zoonotic factors including exposure to pets and farm animals; and environmental factors including source of drinking water and exposure AZD8055 in vitro to lake, river or swimming pools. Clinical characteristics including diarrhea, weight loss, vomiting, abdominal pain and nausea, presence of concomitant microbial infections, antiretroviral use and laboratory characteristics including CD4 + T-cell counts were recorded. This checklist was filled out

by a physician who confirmed patient’s symptoms by physical examination and so on. Diarrhea was defined as three or more watery or loose stools in a 24-hour period. Diarrhea that persisted for more than two weeks was considered chronic; otherwise, it was classified as acute. Weight loss was considered significant when referred patients lost more than 10% of their baseline body weight during their hospitalization. Three fecal samples were collected at two days intervals from each patient and placed in a disposable plastic cup. The samples were taken immediately to the laboratory and stored at −20°C until analysis. The fecal specimens were concentrated using a sucrose solution with a specific gravity of 1.200 at a centrifuge speed of 800

×g for 10 mins. All samples were stained by the modified Ziehl-Neelsen method and examined under Metalloexopeptidase bright field microscopy. A sample was considered Cryptosporidium positive if typical oocysts 4–6 μm in diameter were visible. Fecal samples were subjected to six cycles of freeze–thaw in liquid nitrogen and a 95°C water bath to rupture the oocysts. DNA was isolated from aliquots of frozen stool using the QIAamp DNA stool minikit (Qiagen, Gaithersburg, MD, USA) according to the manufacturer’s instructions. A two-step nested PCR protocol was used to amplify the 18S rRNA gene (830 bp). The fragment of the 18S rRNA gene was amplified by PCR using the following primers: 5′-TTCTAGAGCTAATACATGCG-3′ and 5′-CCCATTTCCTTCGAAACAGGA-3′ for primary PCR and 5′-GGAAGGGTTGTATTTATTAGATAAAG-3′ and 5′-AAGGAGTAAGGAACAACCTCCA-3′ for secondary PCR.