Overview of Hepatitis B in Healthcare Settings
Hepatitis B is caused by a virus that attacks the liver. The virus, which is called hepatitis B virus (HBV), can cause lifelong infection, cirrhosis (scarring) of the liver, liver cancer, liver failure, and death. In 2003, an estimated 73,000 people were infected with HBV. People of all ages get hepatitis B and about 5,000 die per year of sickness caused by HBV. HBV is spread when blood from an infected person enters the body of a person who is not infected. Healthcare personnel who have received hepatitis B vaccine and developed immunity to the virus are at virtually no risk for infection. For a susceptible person, the risk from a single needlestick or cut exposure to HBV-infected blood
Aerosols and HIV
Aerosols should not be confused with droplets and splashes. CDC recommends barrier precautions (face shields, masks, gowns, etc.) to prevent contact with droplets and splashes. Aerosols are not droplets; they are invisible particles less than 10 microns in diameter which float on air currents. Aerosols require considerable energy to generate and are not likely to be present in most clinical settings. There are no known instances of transmission of a bloodborne pathogen by aerosol in a clinical setting. In studies conducted in dental operatories and hemodialysis centers, hepatitis B surface antigen could not be detected in the air during the treatment of hepatitis B carriers, including during procedures known to generate aerosols. This suggests that detection of HIV in aerosols would also be uncommon, since the concentration of HIV in blood is generally lower than that of HBV. Finally, detection of HIV in an aerosol would not necessarily mean that HIV is readily transmissible by this route. In the health-care setting, the major risks for HIV infection are blood contact due to percutaneous injuries and, to a lesser extent, mucous membrane and skin contact. Although CDC is sponsoring additional research on aerosol issues, the possibility that HIV may be transmitted via aerosolized blood must be considered theoretical at this time. For additional information on this topic, refer to an article entitled "An Assessment of the Airborne Route in Hepatitis B Transmission," by NJ Petersen, published in 1980 in the Annals of the New York Academy of Sciences, Volume 353 , pages 157-166.