Infectivity of Hepatitis B Virus in Mothers and Children

William R. Jarvis, MD


October 12, 2012


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I would like to talk about a recent article by Komatsu and colleagues[1] in Japan which looked at infectivity of hepatitis B virus (HBV) in children or mothers who are HBV carriers. Acute hepatitis B infection causes both acute and chronic liver disease. It is a vaccine-preventable disease, and about 177 countries have implemented HBV vaccine as part of their routine immunization schedule. However, a number of countries, including Japan and those in northern Europe, have targeted high-risk groups instead. Body fluids of HBV carriers, including saliva, semen, urine, sweat, and tears, have been documented through polymerase chain reaction testing to be positive for HBV. However, infectivity has only been documented in saliva, serum, and semen.

In this study, Komatsu and colleagues identified children or mothers who are HBV carriers and determined HBV DNA levels in urine, saliva, tears, and serum. They were quantified by polymerase chain reaction. All of these patients were asymptomatic and all were hepatitis B e-antigen positive. HBV DNA levels were ≥ 6 log copies/mL in 39 samples. When you look at the mean levels of HPV DNA, it was 4.3 ± 1.1 log copies/mL for urine, and that was significantly less than what was found for saliva, tears, or sweat. If we look at saliva, it was 5.9 ± 1.2 log copies/mL, and for tears it was 6.2 ± 0.7 log copies/mL. No significant difference was found in the levels for saliva, tears, or sweat. There was a correlation between serum levels and saliva and tears.

They then took tears from the children and inoculated them into chimeric mice. They found that tears were infectious. Now we have data to show that not only are serum, saliva, and semen infectious but tears are infectious as well. And it shows that we should be using strict precautions with all body fluids of patients who are HBV positive, particularly those who have high titers of immunoglobulin M activity.

Until next time, this is Dr. William Jarvis, President of Jason and Jarvis Associates. Thank you.