Changes in frequency of HBV, HCV, HIV and syphilis infections among blood donors in Tehran province 2005 - 2011.

BACKGROUND: Evaluating trends in blood donors' infectious diseases is essential for monitoring the safe supply of blood, donor screening effectiveness, and the occurrence of infections in the blood donor population which consequently gives an idea of the epidemiology of these diseases in the community. The aim of the present study was to assess the prevalence of hepatitis B, hepatitis C, HIV and syphilis by carrying out confirmatory tests in Tehran's blood transfusion center between 2005 and 2011.

METHODS: This was a retrospective study conducted at Tehran's Blood Transfusion Center (TBTC) from 2005 to 2011. All donor serum samples were screened for HBV, HCV, HIV and syphilis using third generation ELISA kits and RPR test. Initial reactive samples were tested in duplicate. Confirmatory tests were performed on all repeatedly reactive donations. For statistical analysis, T- test, ANOVA and Chi-square test were carried out on SPSS software and 95% confidential intervals (95% CI) were used.

RESULTS: Over a period of six years (March 2005 to March 2011), a total of 2,026,628 donations were collected. Out of the total blood donors, 10,476 were positive for HBV, HCV, HIV and syphilis. The overall frequency of HBS Ag, anti-HCV, HIV Ag/Ab and syphilis antibodies were 388,112, 5.4 and 10.5 per 100,000 donations, respectively. The prevalence of HBV among blood donors showed a downward trend over the period of six years. The trend of HCV fluctuated during the period under study, peaking in 2007. The trend of HIV infection frequency had increasing patterns in 2011. The trend of syphilis infection frequency was increasing in 2008 and decreasing after that.

CONCLUSION: Declining trend in prevalence of blood-borne infections indicates the effectiveness of screening methods and selection of appropriate donors. Higher prevalence of blood-borne infections in males, low educated, married, first-time donors and donors who referred to the mobile centers requires a different planning in these groups.