U. Dumpis et al., Transmission of hepatitis B virus infection in Gambian families revealed by phylogenetic analysis, J HEPATOL, 35(1), 2001, pp. 99-104
Background/Aims: Transmission of hepatitis B virus (HBV) in Africa occurs h
orizontally, with most people becoming infected between the ages of 1 and 5
years. The index cases in such events have been assumed to come from withi
n the family unit or from sources outside the immediate family, such as oth
er families or inhabitants of the same compound or village. Here, we define
these routes of transmission by phylogenetic tree analysis of sequences fr
om the entire pre-core/core region of the virus, in Gambian chronic carrier
s.
Methods: Amplification by polymerase chain reaction of serum extracted HBV-
DNA was followed by direct sequencing of the target region. Following editi
ng and alignment of these sequences, phylogenetic tree analysis was perform
ed using the neighbour-joining and maximum-likelihood methods.
Results: Despite the overall conserved nature of the sequences of the pre-c
ore/core region from 142 chronic carriers, distinct clusters were easily de
fined at the family and village level, but not on a wider geographical sepa
ration.
Conclusions: Phylogenetic tree analysis of sequences obtained from family m
embers provided strong evidence of intrafamilial transmission of HBV in at
least two-thirds of the families studied from Gambia, (C) 2001 European Ass
ociation for the Study of the Liver. Published by Elsevier Science B.V. All
rights reserved.