The Hepatitis B Virus (HBV) is a member of the Hepadnavirus family and consists of an outer lipid envelope with a nucleocapsid protein core. It is a DNA virus with a DNA polymerase that has reverse transcriptase activity similar to retroviruses. Statistics from 2016 reveal a total of 3,218 cases of acute hepatitis B in 48 states. This number is likely lower than the actual number due to under-reporting. Actual total cases of 20,900 cases in 2016 have been estimated.
There has been a decline in HBV infections from the years 1990 through 2014. In 2000, the number of reported HBV infections was 8,036. The observed decline has been greatest among children and is due to the now routine use of HBV vaccination for children, a vaccination strategy that started in 1991.
Since 2014, into the present day there have been incremental increases in HBV infections. This is likely due to higher rates of injection drug use in recent years.