Low rate of occult hepatitis B virus infection among anti-HBc positive blood donors living in a low prevalence region in Brazil.
OBJECTIVE
The aim of this study was to determine the rate of occult hepatitis B virus (HBV) infection among blood donors living in a geographic region of low (5.6%) anti-HBc prevalence.


METHODS
Sera from 150 candidate blood donors whose blood was rejected due to total anti-HBc reactivity (despite absence of HBsAg) were tested for anti-HBs and IgM anti-HBc antibodies, as well as for HBeAg/anti-HBe. Serum HBV DNA was sought by using a PCR assay able to amplify part of the surface gene. Viral load was measured in the PCR positive samples.


RESULTS
The pattern 'anti-HBc alone' (without HBsAg and anti-HBs antibodies) was found in 64 (42.7%) subjects. IgM anti-HBc and anti-HBe antibodies were detected in 2 (1.3%) and 80 (53.3%) samples, respectively. No sample was HBeAg-reactive. HBV DNA was repeatedly found in five (3.3%) samples, three of which were anti-HBs positive and two anti-HBs negative. All five HBV DNA positive samples showed a low viral load (<1000copies/ml).


CONCLUSIONS
The data indicated a low rate of occult infection among anti-HBc positive, HBsAg negative blood donors living in a region of low prevalence of infection. Viral load was very low in all HBV infected subjects.
Silva
C M D
CM
Center of Scientific and Tecnological Development, State Foundation for Productivity and Research for Public Health, Porto Alegre, Rio Grande do Sul, Brazil. claudiadornelles@hotmail.com
Costi
C
C
Costa
C
C
Michelon
C
C
Oravec
R
R
Ramos
A B
AB
Niel
C
C
Rossetti
M L
ML
D000328:Adult; D001782:Blood Donors; D001938:Brazil / Q000453:epidemiology; D004279:DNA, Viral / Q000097:blood; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology*; D006510:Hepatitis B Antibodies / Q000097:blood*; D006512:Hepatitis B Core Antigens / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D019562:Viral Load
D004279:DNA, Viral; D006510:Hepatitis B Antibodies; D006512:Hepatitis B Core Antigens