Father-to-child hepatitis B transmission reported

NEW YORK, July 26 (Reuters) Molecular evidence indicates that father-to-child transmission is an ''important route'' of hepatitis B virus (HBV) infection in Japan, Japanese researchers warn in the Journal of Medical Virology.

''At present, only high-risk infants born to chronic HBV-infected mothers are given HBV vaccine,'' note Dr Hitoshi Tajiri, of Osaka General Medical Center, and colleagues. The investigators say their report provides ''substantial evidence'' that fathers can and often do transmit HBV to their children.

Performing a number of genetic analyses, including analyses of two coding regions (S and X gene) of the HBV genetic structure, Tajiri's group showed that eight children from five families contracted HBV from their fathers.

The genetic similarity of the five sets of fathers and children was ''quite high,'' between 99.3 percent and 100 per cent, they report. Further examination revealed that ''all five sets of fathers and children were grouped into the same cluster.'' Based on their findings, Tajiri and colleagues ''strongly'' recommend that Japan's public health agencies ''re-examine the current policy of prevention of HBV transmission for children as soon as possible so that universal vaccination against HBV infection is immediately instituted in Japan for all children, as WHO has recommended.'' It's also ''intriguing,'' they note, that all of the mothers from the five families studied seemed to have contracted HBV infection, most likely via sexual relations with their husbands, and were cured.

All of them were negative for hepatitis B surface antigen and positive for anti-HBV antibodies, indicating they did not have HBV infection but were previously exposed to the virus.

This suggests that ''spouses of HBV-infected husbands should also be protected against HBV infection,'' the investigators write.

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