We found high levels of hepatitis B awareness among surveyed Vietnamese Americans. More than four in five respondents (81%) reported ever having heard of the disease. This proportion was meaningfully higher than the 56% of Vietnamese surveyed during 1998 in Houston, Dallas, and Washington, DC who reported having heard of hepatitis B.32
More than two-thirds (66% of Vietnamese men and 68% of Vietnamese women) reported previous HBV serologic testing; this was a greater percentage than the 38% of Cambodian women who reported testing in a 1999 Seattle survey. We also found that knowledge about specific HBV transmission routes were generally higher than those found in previous studies of Asian American populations.33–35
For example, 48% of Cambodian women in the 1999 study answered correctly that HBV could be transmitted through sexual intercourse (compared to 68% of Vietnamese women in this study), and 11% of Cambodian women were aware that coughing is not a potential route of HBV transmission (compared to 25% of Vietnamese women).35
Our a priori
hypothesis was that levels of HBV awareness, knowledge, and reported previous testing would be higher among Vietnamese women than men. In our previous work we found that Vietnamese women are more likely to have a regular provider than Vietnamese men, and women who receive obstetric care in the US are routinely tested for HBV.30,31
Additionally, hepatitis B vaccination is required for kindergarten and elementary school entry in Washington State, and we further assumed mothers may be more likely than fathers to take responsibility for ensuring children receive immunizations. Contrary to our initial hypothesis, however, there were no differences between men and women with respect to testing levels and overall composite knowledge scores. We did find that Vietnamese women were modestly more likely to report having heard of HBV than Vietnamese men.
Although overall composite knowledge scores did not differ between Vietnamese men and women in our survey, we did find differences in knowledge about specific HBV transmission routes. Women were more likely than men to correctly identify close household contact through eating pre-chewed food, sharing toothbrushes, and sharing razors as routes for hepatitis B transmission. However, women were also less likely to know that eating food prepared by an infected person and coughing are not potential HBV transmission routes. It is possible that these discrepant results are a result of a desirability response bias (i.e., women may be more likely than men to provide the responses they think interviewers want to hear).
Our study has several important strengths, including the use of population-based sampling methods, face-to-face administration of the survey, and high response rates. However, we also acknowledge several limitations. First, we recruited households in an area of Seattle with a high proportion of Vietnamese residents. Our findings may not be applicable to Vietnamese who live outside of cities or in communities with small Asian American populations. Second, only households with listed telephone numbers associated with complete address information were eligible for the survey; it is unclear to what extent such households are representative of Seattle’s Vietnamese community. Third, survey respondents may have had different knowledge levels and preventive behavior patterns than those who were unreachable or refused participation. Last, hepatitis B testing self-reports may be faulty due to inaccurate recall, desirability bias, or confusion about the purpose of blood tests for liver dysfunction. Therefore, we believe our study likely over-estimates HBV testing rates among Vietnamese American men and women.
We speculate that the higher than expected levels of awareness and knowledge of HBV infection among our Vietnamese American respondents may be a result of recent local and national educational campaigns (conducted by such groups as the National Task Force on Hepatitis B for Asians and Pacific Islanders and Stanford University’s Jade Ribbon Campaign).36,37
Nonetheless, one-third of survey participants (33%) did not report previous serologic testing for HBV, and only 62% of those less than 35 years of age (likely the group at highest risk for infection through sexual intercourse) reported having been tested for HBV. Less than three-quarters knew that HBV can be transmitted by eating pre-chewed food (71%), during sexual intercourse (69%), and by sharing toothbrushes (72%) and razors (63%). Few of those surveyed knew that HBV is not spread by eating food prepared by an infected person (36%) nor through coughing (31%).
These data suggest that some Vietnamese Americans may be confusing hepatitis B transmission with other communicable diseases such as hepatitis A and tuberculosis; educational campaigns in Vietnamese immigrant communities should clarify these different diseases and address knowledge deficits found in our survey. We found several differences in knowledge between men and women about specific routes of HBV transmission, suggesting additional benefit in further tailoring educational messages to male and female Vietnamese American audiences. Our findings confirm the need for continued efforts to develop and implement specifically-targeted educational campaigns focused upon reducing the disparately high burden of chronic hepatitis B infection and liver cancer disease in Vietnamese immigrant communities.