The revelation that an estimated one in six Hmong immigrants in Fresno County is infected with the hepatitis B virus (HBV) has health officials stunned.

"There was an audible gasp in the room among all the Hmong attendees," said the Rev. Sharon Stanley in describing the reaction when the data were reported at a recent meeting of the Central Valley Hmong Health Collaborative.

About 62 percent of Hmong screened in Fresno County said they had not been vaccinated or were unsure if they had, according to a study by Dr. Muhammad Y. Sheikh, an associate professor of clinical medicine at the University of California-Fresno Medical Education Program.

HBV can damage the liver, leading to cirrhosis and liver cancer. In California, liver cancer is the leading cause of cancer deaths among Laotian men and the second leading cause among Vietnamese men, according to the California Adult Viral Hepatitis Prevention Strategic Plan 2010-2014.

The study did not evaluate the mode of transmission among those surveyed, but Sheikh said he did not think the virus was spread through sexual contact, sharing of needles or sharing of household items such as razors.

High-risk behaviors such as having multiple sex partners, tattooing, and injecting drugs are not common in the Hmong community, Sheikh wrote in his report.

Nearly 92 percent of the Hmong who tested positive were born outside the United States, and Sheikh said he believes the virus was transmitted at birth.

Eighty-five to 95 percent of mother-to-baby HBV infections can be prevented if appropriate steps are taken at the time of birth, CDC says.

The full report, "Prevalence of Hepatitis B Virus (HBV) Infection Among Hmong Immigrants in the San Joaquin Valley," was published in the Journal of Community Health (2010; doi: 10.1007/s10900-010-9283-0).