Alhusain J. Alzahrani

OBJECTIVE: To assess the prevalence of HIV-1 genetic subtypes in Saudi Arabia in samples that are serologically positive for HIV-1, and compare the HIV-1 genetic subtypes prevalent in Saudi Arabia with the subtypes prevalent in other countries. METHODS: Thirty-nine HIV-1 positive samples were analyzed for HIV-1 subtypes using molecular techniques. The study is a retrospective study that was conducted in Dammam, Kingdom of Saudi Arabia, and in Abbott laboratories (United States of America) from 2004 to 2007. RESULTS: All samples were seropositive for HIV-1 group M. Of the 39 seropositive samples, only 12 were polymerase chain reaction positive. Subtype C is the most common virus strain as it occurred in 58% of these samples; subtype B occurred in 17%; and subtypes A, D and G were found in 8% each. The phylogenetic tree was also identified for the isolates. CONCLUSION: Detection of HIV subtypes is important for epidemiological purposes and may help in tracing the source of HIV infections in the Kingdom of Saudi Arabia.

Drug users and particularly, injecting drug users, are at increased risk for infection with hepatitis C virus (HCV). The aims of the study were to simultaneously detect HCV core antigen and specific antibodies in sera from Saudi drug users using the new HCV combination assay and to compare this data with HCV core antigen, anti‐HCV antibodies and HCV RNA data from the same patients. A total of 297 patients who are followed up or admitted to a drug rehabilitation hospital over a period of 3 years were included in this study. Samples were analyzed using the new HCV Ag/Ab combination assay (Meurex), HCV core Ag assay, HCV antibodies and with the HCV RNA assay. Out of the 297 samples from Saudi drug users, 111 samples (37.4%) have detectable HCV core Ag, 112 samples (37.7%) have detectable HCV antibodies, 118 have detectable HCV RNA, and 116 samples were positive by the HCV Ag/Ab combination assay (39.1%). Out of the 116 samples, HCV core Ag was detected in 110 samples (94.8%), HCV antibodies were detected in 111 (95.7%) samples and HCV RNA was detected in 114 samples (98.3%). In the control group (n = 305), only 2 (0.66%) blood donor were positive by HCV antibodies assay, HCV RNA assay as well as HCV Ag/Ab combination assay. The new HCV Ag/Ab combination assay may well improve the overall quality of diagnosis of HCV infection especially in high risk population such as drug users that necessitates rigorous testing. J. Med. Virol. 80:603–606, 2008.