Application of hepatitis B virus genotyping and phylogenetic analysis in intrafamilial transmission of hepatitis B virus.
BACKGROUND
Infection with hepatitis B virus (HBV) in early life frequently results in persistent infection, and clustering of the chronic infection within a family is common. However, the relative contribution of perinatal mother-to-infant transmission or early horizontal transmission to the intrafamilial clustering of HBV infection remains unclear. Therefore, we used HBV genotyping and phylogenetic analysis to elucidate the modes of intrafamilial HBV transmission in Taiwan.


METHODS
HBV genotypes and serological markers were determined for 103 individuals from 20 families with evidence of clustering HBV infection.


RESULTS
Three patterns of intrafamilial clustering of HBV infection were identified. Among the 20 families, 8 included a hepatitis B surface antigen (HBsAg)-positive mother (pattern I), 7 included an HBsAg-positive father (pattern II), and in the remaining 5, both parents were positive for HBsAg (pattern III). The rates of HBsAg positivity for children of the 3 representative groups of families were 85.7%, 65.4%, and 87.5%, respectively (P = .16). The identical genotyping results between index parent and carrier children indicated that pattern I clustering was caused by maternal transmission, whereas pattern II clustering was caused by paternal transmission. In pattern III clustering, a concordant HBV genotype between carrier children and mother or father was found in 3 and 2 families, respectively. The modes of transmission were confirmed by phylogenetic analysis in 1 family of each pattern.


CONCLUSIONS
In Taiwan, maternal and paternal transmissions are both important in the intrafamilial spread of HBV infection.
Lin
Chih-Lin
CL
Department of Gastroenterology, Taipei City Hospital, Taipei, Taiwan.
Kao
Jia-Horng
JH
Chen
Bing-Fang
BF
Chen
Pei-Jer
PJ
Lai
Ming-Yang
MY
Chen
Ding-Shinn
DS
D000328:Adult; D002353:Carrier State; D005190:Family; D005260:Female; D005838:Genotype; D006509:Hepatitis B / Q000635:transmission* / Q000821:virology*; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008297:Male; D010375:Pedigree; D010802:Phylogeny; D011498:Protein Precursors / Q000235:genetics; D013624:Taiwan / Q000453:epidemiology
D006514:Hepatitis B Surface Antigens; D011498:Protein Precursors