CRF35-AD as the Main Circulating Genotype of Human Immunodeficiency Virus Type 1 Infection in Iran: A Phylogenetic and Demographic-Based Study.

Finding the predominant circulating subtype of human immunodeficiency virus type 1 (HIV-1) and surveying co-infection with other infectious viruses are crucial to making preventive decisions. To this end, 50 Iranian HIV-positive patients made up of 37 men and 13 women were selected. Most of the HIV-positive patients (70%) were intravenous drug users (IDUs), and 48 and 32% of patients were co-infected with HCV and HBV, respectively. The rate of simultaneous infection with HIV, HCV, and HBV was found to be 6%. The p17 region of the gag and the c2-v5 region of the env genes were sequenced and then clustered by phylogenetic analyses. CRF35-AD was specified as the predominant circulating subtype among different high-risk groups. In our survey, most of the patients in the IDU group had co-infections with HCV and HBV. Some possible reasons for the increased transmission risk of HIV in IDUs could be low levels of education, poor hygiene and housing conditions, and limited access to health services.