where did the hepatitis b virus come from
Hepatitis B The virus is transmitted by exposure to infectious blood or body fluids.[1] Infection around the time of birth or from contact with other people's blood during childhood is the most frequent method by which hepatitis B is acquired in areas where the disease is common.[1] In areas where the disease is rare, intravenous drug use and sexual intercourse are the most frequent routes of infection.[1] Other risk factors include working in healthcare, blood transfusions, dialysis, living with an infected person, travel in countries where the infection rate is high, and living in an institution.[1][4] Tattooing and acupuncture led to a significant number of cases in the 1980s; however, this has become less common with improved sterility.[7] The hepatitis B viruses cannot be spread by holding hands, sharing eating utensils, kissing, hugging, coughing, sneezing, or breastfeeding.[4] The infection can be diagnosed 30 to 60 days after exposure.[1] The diagnosis is usually confirmed by testing the blood for parts of the virus and for antibodies against the virus.[1] It is one of five known hepatitis viruses: A, B, C, D, and E.