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.
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
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Silva
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Costi
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Costa
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Michelon
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Oravec
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Ramos
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Niel
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Rossetti
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