Prevalence and trends of transfusion transmitted infections in a regional blood transfusion centre.

Sir,

Transfusion Transmitted Infections (TTIs) are a major problem associated with blood transfusion. Accurate estimates of risk of TTIs are essential for monitoring the safety of blood supply and evaluating the efficacy of the currently employed screening procedures. The present study was carried out to assess the percentage of voluntary donors and find out the prevalence and trends of various TTIs in recent years.

This retrospective study was carried out in healthy blood donors in the age group of 18-60 years presenting to our hospital from January 2003 to December 2008 (6 years). Care was taken to exclude professional donors. The serum samples were screened for Hepatitis B Surface Antigen (HBsAg); antibodies against HIV I and II, Hepatitis C Virus (HCV) by Enzyme-linked immunosorbent assay (ELISA) method. Screening for Syphilis was carried out by Tissue Plasminogen Hemagglutination (TPHA) method.

A total of 157,466 units of blood was collected and screened from January 2003 to December 2008. Of these, a total of 62,542 (39.71%) donors were voluntary, 94,812 (60.22%) were replacements, and 112 (0.07%) were autologous donors [Table 1]. A marked increase in the number of voluntary donors was observed from 15% in 2003 to 70% in 2008.

Table 1

Donor distribution: Voluntary, replacement and autologous

The mean prevalence of the four major transfusion transmitted infections was as follows: HIV- 0.35%, HBV- 1.66%, HCV- 0.65%, and Syphilis- 2.8%, in six years [Table 2].

Table 2

Prevalence of transfusion transmitted infections in donors

At our center, the mean prevalence of HIV was 0.35%. A decrease in the prevalence was seen from 1997 (0.8%)[1] to 2007 (0.3%). Pahuja et al. also reported a decreasing trend in the HIV prevalence in blood donors between 2002 and 2005.[2] The seropositivity for HBsAg in the 6 years has remained relatively constant, with a variation in the range of 1.6-1.8%. This is similar to the seroprevalence found between 1997 and 2002 (1.8%).[3] It is estimated that the global prevalence of HCV infection is approximately 2%.[4] The mean prevalence of HCV infection among blood donors at our center was 0.65%. The seroprevalence has shown an increase from 0.5% in 1997-2002 to 0.65% in 2003-2008. Several authors have found a positive correlation between seroprevalence of Syphilis and HIV; moreover, serologic screening for Syphilis serves as a surrogate marker for HIV.[5] The mean seroprevalence of Syphilis between 2003 and 2007 at our center was 2.8%. This prevalence is high in our blood donors as compared to national figure as reported by other authors.[56]