HIV and Hepatitis Transmission Among Health Care Professionals

There are many common viruses which could potentially be transmitted to health care workers. Two such viruses of particular concern are hepatitis and HIV. Both organisms are considered to be highly virulent with tremendous health consequences. However, it has been documented that hepatitis is more of a concern to health care practitioners than HIV.

HIV is a lentivirus, a subgroup of retroviruses which has a high affinity for CD4 T lymphocytes and monocytes. The mechanism in which HIV infects cells is that it attacks CD4 cells and becomes internalized. The virus replicates itself by generating a DNA copy by reverse transcriptase. Viral DNA becomes incorporated into the host DNA, enabling further replication.

HIV is transmitted primarily through sexual contact, parenteral transmission through intravenous drug users; by contaminated blood products although rare in the United States, and through accidental needlestick with a contaminated object. Since the introduction of universal precaution practices, infection of health care workers through parenteral exposure remains rare. Children are infected primarily by perinatal transmission.

The risk of transmission to health care practitioners is low. The length of time that HIV can survive outside the body is dependant on the amount of HIV present in the fluid and the type of bodily fluid. HIV is a fragile virus and upon drying of the fluid, the viral load is reduced by 90 - 99%. A study of over 2,000 health care workers has been underway for several years to assess the risk of their exposure to people with HIV.

Over 1,000 of these workers had a needle stick accident with a needle that had been used on a person living with AIDS. Of all these people, only 21 show signs of being infected with HIV (as determined by the antibody test). This study shows that AIDS is a difficult disease to get, and even the intimate exposure of these health care workers was not enough to infect them, except in the most extreme cases (Manson 1987)

The term viral hepatitis often is caused by the known hepatotropic viruses, including hepatitis viruses A, B, C, D, and E. Hepatitis A virus (HAV); hepatitis B virus (HBV); hepatitis C virus (HCV); hepatitis D virus (HDV), which requires coexisting HBV infection; and hepatitis E virus (HEV) cause 95% of cases of acute viral hepatitis observed in the United States. Of specific concern to the health care worker is the transmission of hepatitis B.

Hepatitis B routes of transmission include perinatal, sexual and parenteral contact with infected fluids. Careful blood screening has drastically reduced the amount of infected cases seen in the United States however intravenous drug use and sexual activity with infected partners accounts for a majority of new cases each year.

The reason that hepatitis B is of great concern to the health care worker is due to the survival of the virus. According to the CDC, hepatitis is capable of survival outside the human body in blood for up to 7 days. In addition, HBV can survive storage at -20°C and heating at 60°C for 4 hours thus making it an extremely hardy virus unlike the HIV virus. It is because of the hardiness of HBV which makes it a great concern to all health care workers who could potentially come into contact with bodily fluids.