Occult hepatitis B infections among blood donors in Lao PDR.
OBJECTIVE
In Lao People's Democratic Republic, hepatitis B virus is highly endemic. However, blood donations are only screened for HBsAg, leaving a risk of transmission by HBsAg-negative occult infected donors. Here, we characterized first-time blood donors to assess prevalence of hepatitis B virus infections and occult infected donors.


METHODS
Sera were screened for HBsAg, HBeAg and anti-HBs, anti-HBc and anti-HBe antibodies. Occult HBV infections (OBIs) were assessed in HBsAg-negative sera by PCR, and sera of HBsAg positive and occult infected donors were phylogenetically characterized.


RESULTS
9·6% of the donors were HBsAg positive, and 45.5% were positive for at least one of the hepatitis B virus serum markers. More than 40% HBsAg carriers were HBeAg positive, with HBeAg seroconversion occurring around 30 years of age. Furthermore, 10·9% of HBsAg-negative, anti-HBc and/or anti-HBs-positive donors were occult infected with hepatitis B virus. Thus, at least 3·9% of blood donations would potentially be unsafe, but hepatitis B virus DNA copy numbers greatly varied between donors.


CONCLUSIONS
In Lao People's Democratic Republic, a sizable proportion of HBsAg-negative and anti-HBc antibody-positive blood donations are potentially DNA positive and infective for hepatitis B.
Department of Pathology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
P
P
Jutavijittum
I E
IE
Andernach
A
A
Yousukh
B
B
Samountry
K
K
Samountry
T
T
Thammavong
J
J
Keokhamphue
K
K
Toriyama
C P
CP
Muller
D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001782:Blood Donors; D004279:DNA, Viral / Q000097:blood / Q000235:genetics / Q000276:immunology; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology* / Q000276:immunology / Q000635:transmission; D006510:Hepatitis B Antibodies / Q000097:blood / Q000235:genetics / Q000276:immunology; D006512:Hepatitis B Core Antigens / Q000097:blood / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000097:blood / Q000276:immunology; D006515:Hepatitis B virus / Q000235:genetics / Q000276:immunology; D006801:Humans; D007812:Laos / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D015995:Prevalence; D055815:Young Adult
D015415:Biomarkers; D004279:DNA, Viral; D006510:Hepatitis B Antibodies; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens
chronic hepatitis B infection; hepatitis B virus; occult hepatitis B infection; seroclearance; serological markers