[Occult HBV infection in HBsAG negative and anti HBC positive blood donors]

ABSTRACT

In recent years with introduction of better screening tests, the risk of infection with transfusion- transmitted viruses has been reduced remarkably, although obtaining a zero-risk blood supply still remains international blood transfusion services goal. The routine test for detection of HBV infected blood samples is examination of HBsAg with ELISA method but in occult I-mV infection, HBsAg is not detectable by ELISA. Therefore, a more sensitive or complementary test is needed. Some international blood transfusion services have introduced anti-HBc screening as a surrogate test for the presence of HBV infection. The aim of this study was to evaluate the prevalence of occult I-IBV infection in Isfahanian blood donors and the potential value of anti- HBc testing of donors as a screening test to detect occult HBV infection. In this descriptive cross-sectional study, 545 blood units were collected [from Isfahan blood center] and tested by HBsAg ELISA kit from April to June 2004 and then all HBsAg negative samples were tested by anti-HBc ELISA kit. To detect occult HBV infection, all HBsAg negative and anti-Mile positive samples were tested by PCR method. All samples were negative for HBsAg while 43 blood units were anti-HBc positive [8%]. These HBsAg negative and anti-HBc positive blood units were tested for HBV DNA of which five units [% 11.6] were HBV DNA positive. Occult I-IBV infection is a clinical form of HBV infection that cannot be detected by usual method [ELISA] for HBsAg and therefore more sensitive techniques are needed for detection of FIBV infection. PCR is a sensitive technique that detects IIBV DNA even in a trace mounts. Our results identified that more sensitive and complementary tests such as, PC.R and anti-HBc, are essential and helpful to ensure safety of blood units