More than half of children under five living in households with someone who has an active hepatitis B infection were at risk of exposure not from their biological mother, but from another family member. These are the findings of a study presented at IDWeek, the annual conference of the Infectious Diseases Society of America, held in Washington, D.C., from October 21 to 24, Medical Xpress reports.
Researchers led by Karen Jacobson of the Kaiser Permanente research division in California examined data on children under five who were enrolled in Kaiser Permanente Northern California as of June 16, 2023.
The study included 158,169 children living in 131,800 households, each with at least one other member enrolled in the same healthcare system. An individual with an active hepatitis B infection was identified in 1,689 households. A total of 2,024 children lived in these households, accounting for approximately 1.3% of all children included in the study.
Of these children, 41.8% were classified as being at risk of infection at birth, meaning the virus could have been transmitted by their mothers. The remaining 58.2% were at risk of exposure to the virus from other household members.
People with active hepatitis B infections who were not the children’s mothers were older on average than infected mothers: 44 years versus 38 years. In addition, 76.5% of these other infected household members were male.
The researchers also found differences in vaccination timing. All children at risk of infection at birth received a hepatitis B vaccine within their first seven days of life. Among children at risk of exposure to an infected household member, the figure was 93.5%, compared with 86.7% among children with no identified risk.
“A child can be exposed to the hepatitis B virus by anyone with an active infection, not just their mother,” Jacobson emphasized. She noted that it is impossible to know the infection status of every person a child comes into contact with, making vaccination immediately after birth an important way to protect against potential sources of infection, including those that are unknown.
Hepatitis B is a viral infection that can lead to chronic liver disease. Vaccinating infants during the first days of life helps reduce the risk of infection. However, the study assessed the presence of potential sources of infection within households rather than confirmed cases of transmission from specific family members to children.
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