— Christine M. Kukka, Project Manager, HBV Advocate
While new HBV infections have declined dramatically since the early 1990s due to effective immunizations, public health officials continue to examine where new infections are coming from and who is getting infected.
Acting as molecular detectives, CDC officials mapped the genetic make-up and strains (genotypes) of HBV from 1,206 new hepatitis B cases reported between 1998 and 2006. They found that most of the HBV causing infections belonged to genotypes A2 (75%) and genotype D3 (18%). Genotype A originates in Central Asia and the Middle East, while genotype D originates in Africa and the Middle East. However, starting 30 years ago, these genotypes began expanding rapidly in the U.S.
The increase in HBV infections with genotype A2 has occurred primarily among male homosexuals, according to the report published in the September issue of theJournal of Virology.
"The tendency of selectively-expanding HBV strains to be transmitted among male homosexuals highlights the need to improve hepatitis B vaccination coverage among at-risk adults," researchers wrote.
Labels: epidemiology, global distribution of types, origins of HBV
