Prevalence and interaction of hepatitis B and latent tuberculosis in Vietnamese immigrants to the United States

OBJECTIVES: Southeast Asian immigrants, with a high prevalence of both hepatitis B and latent tuberculosis, constitute a large proportion of immigrants to the United States. Isoniazid hepatotoxicity may be associated with hepatitis B. This study was conducted to document the prevalence and interaction of hepatitis B, latent tuberculosis, and isoniazid toxicity. METHODS: Hepatitis B surface antigen (HBsAg) and tuberculin skin testing, was done on 743 Vietnamese immigrants to the Midwest between January, 1991 and December, 1999. HBsAg positive cases were tested for hepatitis B e antigen (HBeAg) All tuberculin skin test-positive patients were treated with isoniazid, unless contraindicated. Complications of isoniazid treatment and compliance with hepatitis B virus immunization recommendations were evaluated. RESULTS: One hundred three subjects (13.86%) had HBsAg, and 43 (5.7%) HBeAg. Prevalences of latent tuberculosis were similar in HBsAg positive (53%) and HBsAg negative (45170 subjects. Sixty-two percent of HBeAg positive versus 19% of HBeAg negative subjects had hepatotoxic side effects requiring discontinuation of treatment (relative risk [RR] = 11.38, Cl = 5.49 < RR < 23.59, p < 0.001). Three cases of severe isoniazid hepatitis occurred in 21 HBeAg positive subjects, versus no cases in 12 1 HBeAg negative cases treated with isoniazid (RR = 7.72, Cl = 5.02 < RR < 11.88, P < 0.001). Only 58% of subjects at risk of developing hepatitis B virus infection were appropriately immunized. CONCLUSIONS: Vietnamese immigrants have a high prevalence of hepatitis B and latent tuberculosis. HBeAg positive cases have a 7.7-fold increased risk of serious isoniazid toxicity and an 11.3-fold increased risk of isoniazid side effects requiring discontinuation of treatment. HBeAg represents an important risk factor for severe isoniazid hepatitis.