High prevalence of hepatitis B among U.S. immigrants

Hepatitis B virus (HBV) screening rates and vaccine-induced immunity are lacking in areas of the world where HBV remains endemic, according to a new analysis of cohort data.

In a study presented this month at the American Association for the Study of Liver Diseases (AASLD) 2023 Liver Meeting in Boston, a team of U.S. researchers reported that HVB prevalence remains ≥5.0% in the populations of eight countries. Of these countries, only 1 has screened most eligible individuals for HBsAg, and 2 have immunized more than 70% of the eligible population.

Led by Matt Sumethasorn, MD, a second-year resident in the USC/Los Angeles General Medical Center Internal Medicine Residency Program, the researchers sought to identify a large group of people in the United States enriched for foreign-born individuals. They note that the U.S. Centers for Disease Control and Prevention (CDC) currently recommends that all adults over 18 years of age should be screened for HBV more than once, regardless of risk disclosure.

“Chronic hepatitis B remains a global health problem due to insufficient understanding of the infection, with high morbidity and mortality despite readily available and effective treatments,” they wrote. “Foreign-born Hepatitis B virus seroprevalence was significantly higher among the U.S. general population.”

Sumethasorn and colleagues conducted a retrospective analysis of adults 18 years and older who received ≥2 outpatient primary care visits from 2017 to 2021 in a large, highly foreign individual-represented health care system in Los Angeles. The team estimated country- and region-specific HBV screening rates as the proportion of all eligible individuals tested for HBsAg.

The researchers estimated age-adjusted HBV prevalence as the proportion of people who were screened who were HBsAg-positive, while also examining those who tested negative for HBsAb. HBV immunity rate was defined as HBsAb titer ≥12 U/L among those who tested negative.

To determine country-specific prevalence, the team used six World Health Organization (WHO) regions and identified countries that screened ≥100 people for national analysis.

The final analysis included more than 200,000 individuals who met inclusion criteria, representing 174 different countries of birth; the majority (86.2%) were from the Americas region. The median age was 55 years; 41.2% were male and 38% were born in the United States.

The researchers observed an age-adjusted HBV prevalence of 0.4% (95% CI, 0.3 – 0.5) among U.S.-born individuals and 1.2% (95% CI, 0.3 to 0.5) among foreign-born individuals. CI, 1.1 – 1.3). HBV screening rates were below 45% in all six regions, and immunization rates were below 30% in both the Americas and Europe regions.

Only Afghanistan and Cambodia were observed countries providing screening rates >50%. Immunization rates varied widely, from 9.1% (95% CI, 0.2 to 42.3) in Chile to 77.8% (95% CI, 57.7 to 91.4) in Myanmar. The immunization rate among U.S.-born people was 36.0% (95% CI, 35.3 – 36.7), while the immunization rate among foreign-born people was 26.7% (95% CI, 26.2 – 27.2).

Nearly all countries with an estimated HBV prevalence of ≥5% are in Asia, including Vietnam (12.8%); China/Taiwan/Hong Kong (10.5%); Cambodia (10.2%); North Korea (8.2%); Thailand (7.2 %); Myanmar (7.2%); Nigeria (5.5%); and Ethiopia (5.1%).

Sumethasorn and colleagues concluded that high prevalence of hepatitis B virus is consistently observed among immigrants to the United States from endemic countries.

“Hepatitis B virus screening rates and immunity are low regardless of country of birth, suggesting that previous risk-based screening strategies based on national prevalence have failed to adequately identify people with or at risk of HBV infection,” they wrote. of people.” “Interventions combining universal HBV screening and vaccination are needed to reduce HBV-related morbidity and achieve elimination.”

refer to

^{Sumethasorn M, Wong C, Terault N, Zhou K. Country-specific screening, prevalence, and immunization rates for hepatitis B infection in the United States. Paper presented at: Liver Conference. Boston, MA November 10-14, 2023.}