Prevalence and Trends of Common Transfusion Transmitted Infections Using Serological and Nucleic Acid Markers in Saudi Blood Donors

Abstract

Background: Epidemiologic studies on the prevalence of transfusion-transmitted infections (TTIs) in Saudi Arabia (SA) regions are limited. This study investigated prevalence of HBV, HCV, and HIV using both serological and nucleic acid testing (NAT) methods to determine temporal and geographic trends among blood donors in Makkah. Our secondary objective was to realize the most suitable NAT format, without compromising sensitivity of NAT results by using individualized or mini-pool testing. Methods: Serologic and NAT screening records of 22,963 blood donors from January 2011 to December 2014 were evaluated for HBsAg, Anti-HBc, Anti-HCV, Anti-HIV, HBV-DNA, HCV-RNA, and HIV-RNA. Prevalence rates were calculated for TTIs per hundred donations and additional analysis was conducted to examine donor profiles associated with positive serologic and NAT results. Known viral loads (<20 IU/ml for each HBV and HCV and <50 copies/ml HIV) diluted in negative plasma were evaluated by NAT screening. Results: Overall serological prevalence of HBs-Ag, anti-HBc, anti-HCV, and anti-HIV were 0.7, 6.7, 0.44, and 0.07%, while molecular HBV-DNA, HCV-RNA, and HIV-RNA were 0.72, 0.05, and 0.03% respectively. There was a gradual decline in percentage of infected donor blood based on combined serological and/or NAT screening from 8.3% in 2011 to 6.8% in 2014 with an overall 7.4% (n=1,689) TTI-infected. Prevalence of HBV, HCV and HIV was unevenly distributed among different regions in SA. Analysis of donor serologic and molecular profiles revealed solitary anti-HBc- positive was the highest (6%) donor profile followed by anti-HBc-positive/HbsAg-positive/HBVDNA positive donor profile at 0.6%, and solitary anti-HCV at 0.4%. Simulation of mini-pool NAT format by dilution of known viral loads at 1:6, resulted in 70% reduction in HBV detection, 50% for HCV, and 40% for HIV. Conclusions: This is the first study to provide current data collectively comparing prevalence and trends of HBV, HCV, and HIV serologic and nucleic acid markers amongst Saudi blood donors. Makkah boasts one of the lowest TTIs prevalence in SA and to surrounding countries. The majority of seropositive and NAT-reactive blood donors are in a state of acute, chronic or resolved HBV infection. Individual donor NAT is the ideal methodology that should be applied in SA where diluted samples could compromise clinical sensitivity and blood safety.