Prophylaxis strategy prevents perinatal HBV transmission

(HealthDay)—Prenatal screening followed by immunoprophylaxis for infants of mothers with chronic hepatitis B virus (HBV) infection decreases perinatal transmission, according to research published online May 27 in the Annals of Internal Medicine.

Ai Kubo, Ph.D., of Kaiser Permanente in Oakland, Calif., and colleagues conducted an observational study of 4,446 infants born to 3,253 HBV-positive mothers. The authors sought to assess the efficacy of an immunoprophylaxis program.

The researchers found that the infant HBV infection rates per 100 births were 3.37 (95 percent confidence interval [CI], 2.08 to 5.14) for e antigen-positive mothers and 0.04 (95 percent CI, 0.001 to 0.24) for e antigen-negative mothers. Among mothers who received testing, the lowest viral load level associated with transmission of HBV was 6.32 × 10⁷ IU/mL. Infection rates per 100 births were 3.61 (95 percent CI, 0.75 to 10.56) among mothers with viral loads of 5 × 10⁷ IU/mL or greater (83 births) and 0 among mothers with viral loads less than 5 × 10⁷ IU/mL (831 births), regardless of e antigen status.

"A negative e antigen status or a viral load less than 5 × 10⁷ IU/mL (90.9 percent of women tested) identifies women at extremely low risk for transmission after immunoprophylaxis who are unlikely to benefit from further interventions," the authors write.