More Than Half of Young Children’s Household Hepatitis B Exposure Involves Contacts Other Than Mothers, Study Finds

WASHINGTON — A retrospective cohort study found that young children’s exposure to hepatitis B virus (HBV) in the household was more often linked to contacts other than their mothers.

Among more than 158,000 children younger than 5 years, 1.3% lived with someone who had an active HBV infection. Of these exposed children, 58.2% had contact with a nonmaternal household member, compared with 41.8% whose exposure was linked to their mothers, according to Karen Jacobson, MD, MPH, of the Kaiser Permanente Vaccine Study Center in Pleasanton, California, who presented the findings at the IDWeek annual meeting.

“Our findings show that even if every maternal infection could be identified accurately, it would not account for all potential exposure to an infected father, grandparent, or other household member — or anyone else the children might come into close contact with outside the home,” Jacobson said during a press briefing before the meeting.

“Transmission of hepatitis B to children from nonmaternal sources is currently quite rare in the United States because vaccination rates are high,” she noted. “But if vaccination rates decline, more infants could be at risk.”

A universal dose of the HBV vaccine at birth protects babies from household exposure.

In December, the CDC’s Advisory Committee on Immunization Practices (ACIP) voted to reverse more than three decades of U.S. vaccine policy by ending its recommendation for a universal HBV birth dose for infants whose mothers test negative for hepatitis B surface antigen (HBsAg).

ACIP continues to recommend that infants born to mothers who test positive for HBsAg or whose mothers have not been screened receive a birth dose within 12 hours of delivery. When a mother tests negative, however, ACIP recommends shared decision-making about the birth dose.

Critics have warned that dropping the universal birth dose could lead to preventable acute and chronic HBV infections, liver cancers, deaths, and millions of dollars in additional health-care costs. A recent modeling study estimated that the shared decision-making approach would increase chronic HBV infections by 83%.

For infants who do not receive a birth dose, ACIP recommends delaying the first dose of the three-dose series until at least age 2 months. Jacobson’s study found, however, that 4.2% of children exposed to HBV through a nonmaternal household contact remained unvaccinated at 30 days of age — within that two-month window.

“The latest ACIP recommendations focus primarily on maternal exposure, but it is important not to overlook other potential sources of exposure,” Jacobson said.

Although 95% of infants exposed at birth were tested for HBV, only 3.6% of children with household exposure were tested. All infants exposed at birth were vaccinated within seven days.

Children with household exposure were more likely to be vaccinated than those without such exposure, 93.5% versus 86.7%. Jacobson said the difference suggests that some families or health-care providers recognized the potential risks associated with household exposure.

Jacobson and colleagues analyzed laboratory and vaccination data through March for children younger than 5 who were members of Kaiser Permanente Northern California (KPNC). Using addresses, the researchers linked the children to their birth mothers and to households containing at least one other KPNC member.

The 158,169 children lived in 131,800 households, and 1,689 of those households included a person with active HBV. Nonmaternal household contacts were older than maternal contacts, with median ages of 44 and 38 years, respectively; 76.5% were male.

Because children are not routinely screened for HBV, the researchers could not determine whether any of the household-exposed children developed an HBV infection.

Although the study’s 1.3% household-exposure rate may appear low, Jacobson said it is likely an underestimate. Infection during infancy is highly likely to become chronic and result in lifelong consequences, she added.

Limitations included inaccurate address information and possible underestimation of exposure when household contacts with HBV were not KPNC members.

Source link