الفهرس 
TitleOnly 14 pages are availabe for public view
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Abstract
HBV remains a major public health problem worldwide. chronic sequelae of
hepatitis B infection include liver cirrhosis, hepatic failure and hepatocellular carcinoma
(HCC).
The global prevalence of HBsAg varies greatly and countries can be defined as
having a high, intermediate and low prevalence of HBV infection based on a prevalence of
HBsAg carriers. The prevalence of HBsAg in Egypt is of intermediate endemicity (2–8%).
Nearly 2-3 million Egyptians are chronic carriers of HBV.
Routine screening of blood donors for hepatitis B surface antigen (HBsAg) has
greatly enhanced transfusion safety However, it was demonstrated that HBV transmission
by blood components negative for HBsAg can still occur and HBV transmission remains
the most frequent transfusion-transmitted viral infection.
Occult hepatitis B infection (OBI) is defined by the presence of HBV-DNA in the
liver tissue and/or in the serum of HBsAg negative individuals
The aim of this study was to determine the frequency of occult HBV infection among
100 HBs-Ag negative blood donors.
This study was carried out in the Department of Microbiology at the Medical
Research Institute, Alexandria University, during the period between 2013- 2014. It
included 100 HBsAg negative blood donors who attended the Medical Research Institute
blood bank.
Donors were subjected to the blood bank questionnaire including personal data as
(age, sex, etc) as well as health data (history of previous infection with TB,Viral hepatitis
or HIV, previous surgical interference, and dentistry). Exclusion criteria included HCV,
HIV exposure blood donor.
Blood samples were collected from all donors, left to clot. Serum was separated by
centrifugation at 1500 rpm then stored in small aliquot at -20°C for further investigation.
Sera were tested for the following investigations:
5. Determination of the liver enzyme Alanine aminotransferase (ALT ) by full automated
(Biosystem)®.
6. Detection of HBsAg by ELISA (Abott Murex Diagnostic Division, kent, PUK)®
7. Detection of the following serological markers for HBV by ELISA (DIA.PRO)®
d) Antibodies against hepatitis B core antigen (anti- HBc )
e) Antibodies against hepatitis Be antigen (anti- HBe )
f) Antibodies against hepatitis Bs antigen (anti- HBs )
8. Detection of occult HBV by:
a) Conventional nested PCR for Pol,Core and X genes.
Summary and Conclusions
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b) Syber green I Real Time PCR (AB: Applied Biosystem)® using specific primers for S
gene.
c) Quantitative determination of HBV viral load by Taqman probe technique (ARTUS)®
in blood donors testing positive for HBV genes.
The majority of the blood donors included in this study were males (94%), and 66%
of them were in the age range 25-40 ys.
Among the 100 HBsAg negative blood donors 12% were anti-HBc positive,11%anti-
HBs positive, and only 2% anti-HBe positive, while 84% were negative for all serological
markers. Anti-HBc was the sole marker in only 5% of cases.
Pol gene was detected in 19% of the 100 HBsAg negative blood donors. 16 (19.05%)
out of the 84 blood donors negative for all serological markers were positive for Pol gene,
while 2 (16.7%) out of the 12 Anti-HBc positive blood donors were positive for Pol gene.
Pol gene was detected in 1 (25%) out of the 4 positive anti-HBs alone, while Pol
gene alone or with Core and /or X genes were detected in 4 out of 5 positive anti-HBc and
anti-HBs blood donors.
Core gene was detected in 6% out of the 100 HBs Ag negative blood donors.
X gene was detected by nested PCR technique in 6% of the 100 HBs Ag negative
blood donors. HBx was significantly associated with Anti-HBc positivity since 4 (33.3%)
out of the 12 Anti-HBc positive cases were HBx positive. While the remaining 2 (2.4%)
out of the 84 Anti-HBc negative were HBx positive.
S gene was detected in only 5 out of the 100 HBsAg negative blood donors using the
SYBR Green technique 4 of them were negative for all serological markers.
HBV DNA could not be detected by TaqMan probe technique (Artus) in any of the 5
tested samples.
All the 100 HBsAg negative blood donors had normal ALT values irrespective of
their serological profiles and the presence or absence of HBV-DNA.
Our results confirmed that conventional nested PCR should be considered as the
most sensitive test for HBV-DNA detection.