BACKGROUND: Approximately 240,000,000 persons are infected with hepatitis B virus (HBV) worldwide; prevalence ranges from <1% to >8% by country. Infected women have a high risk of transmitting HBV to their children at birth, and 90% of infected infants will develop chronic HBV infection. Perinatal transmission is preventable with hepatitis B vaccine, which was first licensed in the United States (US) in 1981. Understanding the epidemiology of HBV infection in pregnancy in New York City (NYC) is required to inform prevention activities.
METHODS: We assessed maternal demographics (race, country of birth, and age) and trends in incidence of births to HBV-infected mothers in NYC over a 15-year period (1998-2012). Data on mothers was obtained from the NYC Perinatal Hepatitis B Surveillance database. Mothers were included in the analysis if they 1) gave birth to a live infant; 2) resided within NYC at delivery; and 3) delivered in NYC. Citywide birth data was obtained from NYC Vital Statistics. The incidence of births to HBV-infected mothers per 100,000 live births was calculated by year and stratified by mother’s country of birth. Trend analyses were conducted using JoinPoint software to assess annual percentage change (APC) in incidence.
RESULTS: Overall, 25,175 mothers met the inclusion criteria. The median number of births to HBV-infected mothers/year was 1,719 (range: 1,324, 1,928); median incidence was 1,507 per 100,000 live births (range: 1,156 in 1998, 1,633 in 2007). Ninety-four percent of mothers were born outside the US, of which, 58% were born in China. Sixty-seven percent of mothers were Asian, 22% were Black, 1% were White, and 11% were Other or unknown race. Trend analysis indicated increasing incidence of births to HBV-infected mothers from 1,156 to 1,507 per 100,000 live births between 1998 and 2003 (APC=4.7%, p<0.01). Incidence of births among US-born mothers declined from 330 to 152 per 100,000 live births between 1998 and 2012 (APC=-8.2%, p<0.01). Incidence of births among foreign-born mothers increased from 1,877 to 2,866 per 100,000 live births between 1998 and 2007 (APC=3.7%, p<0.01).
CONCLUSIONS: Incidence of births to HBV-infected mothers increased citywide between 1998 and 2003 and remained stable thereafter. A consistent decline in incidence was observed among US-born mothers, likely due to the success of US hepatitis B vaccination efforts. Incidence of births among foreign-born mothers increased until 2007 and remained stable thereafter, highlighting the need for successful hepatitis B vaccination programs worldwide in order to eliminate perinatal HBV in the US.