Clinical

Sexual transmission blamed for high HBV infection rate

Last Updated: 2009-11-10 17:45:10 -0400 (Reuters Health)

By Sue Mulley

HONG KONG (Reuters Health) - Horizontal transmission, probably by sexual contact, appears to be to blame for perpetuating the high prevalence of hepatitis B virus (HBV) infection in pregnant women here, according to local researchers presenting at the 5th Asia Pacific Congress in Maternal Fetal Medicine.

"The prevalence of HBV infection in pregnant women is around 10% and hasn't changed during the past 20 years," said Dr. Terence T. Lao of the Chinese University in Hong Kong, quoting a prospective cohort study of 58,736 pregnant women he and his colleagues conducted recently.

"We wanted to figure out factors associated with the prevalence of HBV carriage to try to minimize hepatitis B infection in the future," he said in an interview with Reuters Health.

Dr. Lao and his colleagues recruited 1,580 pregnant women from the university's obstetric unit who were prepared to complete a two-hour, self-administered questionnaire on their sociodemographic, obstetrical and medical history.

The prevalence of HBV carrier mothers (hepatitis B surface antigen positive) was 9.1%, including 4.8% of women with a history of vaccination.

While mainland Chinese maternity tourists were most likely to be HBV carriers (OR, 7.62), mainland Chinese immigrants also were more likely to be carriers (OR, 3.65) compared to their Hong Kong Chinese counterparts.

HBV carriers were also more likely to report a positive family history due to an infected mother (OR, 3.72) or other family member (OR, 5.36).

Women who had not been vaccinated previously were also more likely to be carriers (OR, 4.3), as were women who had been tested previously for HBSAg (OR, 2.26).

"Women who had previously been tested for HBSAg probably suspected they had been exposed to the hepatitis B virus," Dr. Lao noted, recommending that hepatitis B status be reconfirmed in women previously vaccinated.

"In the long run, our universal (HBV) vaccination strategy in infancy should take effect but in the meantime, we need to consider catch-up vaccinations," Dr. Lao told Reuters Health.

"Our findings suggest that horizontal transmission within the family setting, probably due to the spouse, played a more significant role than vertical transmission," the researcher added.