Hepatitis B follow-up among Indochinese refugees.

During 1979 and 1980 the Department of National Health and Welfare carried out a survey and later routine testing to determine the prevalence of serologic markers of hepatitis B in Indochinese refugees entering Canada. Between March and July 1981 the hepatitis-B-marker status of 220 selected refugees in the Ottawa-Hull area was reassessed. Overall, 173 (79%) of the participants had the same serologic markers when retested, but in 47 (21%) the markers had changed. The most significant changes were the loss of antigenemia in 22% of those who had been HBsAg-positive and the appearance of evidence of infection in 18% of those who had been seronegative. Most of these changes occurred among persons under 30 years of age, especially females aged 10 to 19 years.