Our study found that 16.7% of Hmong in the San Joaquin Valley might be chronically infected with HBV. We did not evaluate the mode of transmission of HBV among the study participants. However, the literature suggests that the majority of Asians contract the virus during birth or in their early childhood [1
]. Our study showed that nearly 92% (n
= 79) of HBsAg positive patients were born outside the United States. It is most likely that this Hmong population was already infected at the time of immigration to the United States. Our study found that nearly 75% (n
= 63) of those who tested positive for HBV infection were married or previously married. Engaging in high risk behavior, such as having multiple sex partners, tattooing, and injecting drugs are not common practices in this community. A similar observation was made among Hmong in Thailand in an earlier study [23
]. The majority of the participants were unaware of any known liver disease. These findings are compatible with previously published data in Asian populations [24
Rein et al. [13
] published a recent study reporting the prevalence of HBsAg among refugees entering the United States during 2006–2008. They report a prevalence of 6.5% in Eastern Asians and 10.5% in Southeast Asians. The prevalence in those from Vietnam and Laos were 3.2 and 2.3%, respectively. However, this study was limited due to lack of information about the age and sex of the refugees. In comparison to CDC data from 1991 [29
], the prevalence in Hmong refugees decreased from 15.5 to 2.3% in 2008. This 1991 prevalence for Laos was reported for the Hmong and for other Laotians without a single population-wide estimate. The decline in prevalence may be attributed to many factors, such as increased vaccination. The prevalence of 15.5% reported in 1991 is more consistent with the prevalence reported in our study because the majority (53.1%) of the Hmong we screened had lived in the United States for 20–29 years.
There are several limitations to our study. First, the free HBV screening sites were all located in Fresno County. Therefore, our findings may not be generalized to the Hmong population in other parts of the United States, or even to the entire Hmong population in the Central Valley due to our sampling frame. Second, the reluctance of this population to participate in screening may have affected the true prevalence. Many Hmong were afraid of getting their blood drawn and were apprehensive of the results. They were also worried about their family members knowing their health status. In the Hmong and other Asian American communities, hepatitis B may be stigmatized with having sexual partners, which can lead to ostracism. These observations are consistent with findings from other Asian American screening studies [24
]. Therefore, the prevalence reported in this study may be an underestimate of the true prevalence. Nearly 62.4% of the 534 screened Hmong indicated that they were not vaccinated or were unsure of their vaccination status. The majority of these patients had no primary care physician to provide further treatment, screening for liver cancer, or offer vaccination and preventive measures to curtail the transmission of HBV to their families.
The viral hepatitis surveillance system in the United States has been highly fragmented and poorly developed. There is a paucity of knowledge and awareness about chronic viral hepatitis on the part of health care and social service providers, at risk populations, members of the public, and policy makers. There is insufficient understanding about the extent and seriousness of this public health problem and inadequate public resources have been allocated to prevention, control, and surveillance programs. Due to inaccurate estimates of the burden of disease in the United States, policy-makers and the state governments could not allocate sufficient resources to viral hepatitis prevention and control programs. Between 2007 and 2008, the California Department of Health provided vaccination against hepatitis B to nearly 30,000 individuals. However, Asians Americans comprised only 7% of the vaccinated population. STD clinics made up 63% of the setting in which vaccination occurred, with community medical centers only accounting for 7% [30
The Centers for Disease Control and Prevention has been recently recommended by the Institute of Medicine to conduct a comprehensive evaluation of the national viral hepatitis public health surveillance system. As per these recommendations [31
] there is a need to develop specific cooperative viral hepatitis agreements with all state and county health departments to support core surveillance for viral hepatitis. This cooperative effort would support and conduct targeted active surveillance, including serologic testing, to monitor incidence and prevalence of viral hepatitis in populations not fully captured by core surveillance. The collaboration would allow key stakeholders to develop innovative and effective educational outreach programs to at risk individuals while increasing awareness in the general population.
Hepatitis B infection and its complications such as cirrhosis and HCC are largely preventable. We hope that adherence to the Institute of Medicine’s recommendations will provide an opportunity to decrease the impact of this disease in Asian Americans as well as the entire global community.