Molecular epidemiology of a large community-based outbreak of hepatitis B in Bristol, U.K.

BACKGROUND

A large outbreak of hepatitis B virus (HBV) infection in the U.K. occurred between 2001 and 2005 in Bristol, U.K.

OBJECTIVES

To identify HBV strains circulating amongst risk groups in the HBV outbreak cohort.

STUDY

DESIGN

Cross-sectional study of acute HBV outbreak cases in Bristol.

RESULTS

HBV sequences from sera of 95 of the 237 cases (40%) were characterised. The majority of cases (77%) were found to carry an HBV variant belonging to genotype D, designated HBV(BV). Eighty-eight percent (36/41) of sequences from injection drug users were HBV(BV) as were 70% (19/27) from those with heterosexual intercourse as the primary identified risk factor. Of 15 sequences characterised from cases of pre-outbreak acute or chronic hepatitis B residing in Bristol, 40% also carried HBV(BV); the earliest was from a case identified in 1994.

CONCLUSION

The findings from this study link the spread of HBV(BV) from injecting drug users to the general population through heterosexual intercourse during the outbreak. The molecular sequencing of specimens from this outbreak reports the emergence of HBV(BV), a HBV strain circulating in Bristol and South West England, as the cause of one of the largest outbreaks of acute hepatitis B in the U.K.