Hepatitis B Virus (HBV) Transmission Rate among Children Born to Chinese-American Mothers

1. Hepatitis B Virus (HBV) Transmission Rate among Children Born to Chinese-American Mothers with Chronic Hepatitis B (CHB) in the New York Downtown Area Li-Jun Mi, MD, PhD1, Jeffrey Karsdon, MD2, William M. Huang, MD3, Betty Chiang, MD4, Marc G. Ghany, MD, MSci5, Giuseppe DelPriore, MD, MPH3, Peter Wong, MD3, Eric Poon, MD6,7, Michelle Leong, RN7, Robert S. Brown, MD, MPH8 1Out-Patient Division, Dept. of Medicine, 2Neonatology, Dept. of Pediatrics, 3 Dept. of Obstetrics & Gynecology, 6Dept. of Pediatrics, New York Downtown Hospital, New York; 4Hepatitis Medical Sciences, Gilead Sciences, Inc., Foster city, CA; 5Liver Disease Branch, National Institutes of Health, NIDDK, Bethesda, MD; 7Chinese Community Partnership for Health, New York; 8Division of Liver Disease and Transplantation, Columbia University Medical Center, New York INTRODUCTION RESULTS Table 2. Prenatal Characteristics of 599 Chinese-American Mothers with CHB in the New York Downtown Area Perinatal transmission is the most frequent source of HBV infection worldwide, with reported rates of 3-39%, despite newborns receiving standard passive-active immunoprophylaxis and vaccination. In the US, about 24,000 infants are born to mothers with CHB annually, with an estimated HBV transmission rate of 1%. However, complete and accurate data on the HBV transmission rate is not available in the US. Aims: 1) Determine the HBV perinatal transmission rate in Chinese-Americans whose CHB prevalence is 10-15%. 2) Evaluate risk factors associated with the HBV transmission; 3) Identify impediments to proper follow-up of infants born to mothers with CHB in this population. The follow-up approachability of the 599 mothers is shown in Table 1. More than sixty percent of the mothers were unable to be contacted. About 37% of those contacted mothers (n=175) had sent their children back to China at age of 3-24 months to be taken care of by extended family members. As of October 1, 2009, 76 mothers-81 infants pairs were evaluated. HBeAg, perinatal HBV DNA levels and other maternal characteristics are shown in Table 2. Seven out of 76 mother (9.2%) delivered 8 babies (9.8%) whose HBsAg were positive by the age of 24 months. Among the seven mothers, 5 were HBeAg positive, 1 unknown, and 1 negative. The one with HBeAg- had a preterm prelabor rupture of membrane. Her baby became HBsAg- at age of 3 years, and anti-HBs developed after 6 doses of HBV vaccine. Perinatal HBV DNA were only available in 3 of these mothers (all HBeAg +) with 2 at 108 and 1 at 109 copies/ml (Table2). None of these 7 mothers had breastfed, nor had they received anti-HBV treatment during or within 12 months of pregnancy. Of those 8 babies who were infected with HBV, 4 were born to mothers who had mild peripartum complications (premature prelabor rupture of membrane, late preterm birth, oligohydramnios, and amniotic infection, respectively). Of the remaining 73 babies, 61 (83.6%) developed anti-HBs by the age of 36 months, 9 unknown, and 3 were negative for both HBsAg and anti-HBs despite standard immunoprophylaxis and vaccination. Among the mothers with know HBeAg status (n=58), HBeAg+ showed a higher risk of HBV transmission with an OR 11.25 (p=0.02, 95%CI 1.56 – 77.34). METHODS In this retrospective study, newborns at risk for HBV infection were identified by merging two databases at New York Downtown Hospital (NYDH): pregnant women with CHB, and newborns receiving hepatitis B immune globulin (HBIG). 641 babies were born to 601 mothers with CHB (mean age 28.9 years) at NYDH from September 1, 2005 to December 31, 2007. All 599 mothers of Chinese descent were invited by letter, followed by phone calls to participate. Maternal HBeAg, anti-HBe, HBV DNA, ALT levels, history of anti-HBV treatment prior to delivery, perinatal complications, breastfeeding and presence of any infected family member(s) were recorded. Infants’ HBsAg and anti-HBs results at 6-36 months were obtained from pediatricians’ records. The study was approved by the NYDH IRB and all mothers provided written informed consent. CONCLUSION AND DISCUSSION Table 1. Follow-up Approachability of 599 Chinese-American Mothers with CHB in the New York Downtown Area The overall HBV transmission rate of 9.2% in this Chinese-American population despite standard HBV immunoprophylaxis at birth and adequate vaccination, is much higher than previously reported in the US. Mothers with positive HBeAg are at higher risk of HBV transmission to the newborns (OR=11.25). Therefore, it should be highly recommended that HBeAg status be tested in all pregnant women with CHB, and if possible, the HBV DNA level. Due to incomplete follow-up, possible bias may affect the actual rate. Multiple socioeconomic factors represent major barriers to adequate follow-up in this population. Acknowledgement: This study is partially sponsored by Gilead Science, Inc. We are thankful to Ms. Wan Leung for her assistance in contacting to the subjects. We also appreciate the File Room staff and nursing staff in Neonatology unit for access to the medical records.