Transfusion. 2014 Jan 3. doi: 10.1111/trf.12521. More at:
Recently, strategic planning was initiated by the National Blood
Transfusion Services Pakistan to improve its blood bank facilities. Emphasis
has been placed on appropriate screening of blood products. Located in the
southern region, Aga Khan University Hospital is a 700-bed tertiary care
academic institute with comprehensive blood banking. Screening of blood donors
has been based on verbal screening and serologic testing to date. Additionally,
the need of implementing nucleic acid testing (NAT) was considered in 2011
because of an upsurge in hepatitis epidemiology. The aim of this study was to
analyze the efficacy of this additional donor screening program and to evaluate
the impact of NAT on the yield and residual risk of transfusion-transmissible
viral infections.
A total of 42,830 blood donations collected between 2011 and 2012
were screened for routine serologic assays. Only serologically negative donors
(n = 41,304) were tested for NAT. The frequency of viral infections was evaluated
through serologic techniques and NAT yield for viral agents was estimated for
computing window period donors. Residual risk per million donors was computed
for viral infections in seronegative blood donors.
Serologic work-up showed 1571 abnormal screening results in 1526
blood donors with the following results: hepatitis C virus antibodies
(anti-HCV; n = 708), hepatitis B surface antigen (n = 555), human
immunodeficiency virus antibodies (anti-HIV; n = 29), malaria (n = 30), VDRL
(n = 249), and coinfection (n = 45). Thirty-five NAT-reactive samples were
identified: HIV-1, one; HCV, 27; and hepatitis B virus (HBV), seven. Incident
rates per 105 donors
were highest for HCV (453.3) followed by HBV (171.5) and HIV (72.2). Calculated
residual risk per million donors was highest at 1 in 10,900 for HBV,
intermediate at 1 in 13,900 for HCV, and least at 1 in 62,600 for HIV.
Incidence rates and estimated residual risk indicate that the
current risk of transfusion-transmitted viral infections attributable to blood
donation is relatively high in this country. The study recommends the parallel
use of both serology and NAT screening of donated blood in countries that have
high seroprevalence of these viral infections.
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