Blood-borne pathogens and nosocomial infections.

Guidelines to prevent the transmission of blood-borne infections have evolved rapidly since the recognition that "serum hepatitis" could be transmitted to health care personnel via percutaneous exposure to blood. The HIV epidemic focused renewed attention on the problem of protecting health care personnel, culminating in "standard precautions" for patient care, which emphasized the use of gloves for all contact with blood and body fluids. This focus on protection of the health care worker sometimes obscures the other important functions of gloves: protection of patients from microorganisms on the hands of providers and prevention of patient-to-patient transmission of nosocomial pathogens. The risk of infection after percutaneous exposure to the 3 major blood-borne viruses-hepatitis B virus (HBV), hepatitis C virus (HCV), and HIV-varies greatly. The risk for a nonimmune individual exposed to HBV may be >30% if the source is Hb(e)Ag-positive. The average infection rate for HCV is 1.8%. For HIV, the average risk is 0.3%, but is higher with deep injury, when there is visible blood on the device, when a needle has been in an artery or vein, or when the source patient is in the terminal phase of HIV. Prompt administration of anti-HIV therapy reduces risk by about 80%. Mucous membrane and cutaneous exposures carry less risk. Recent efforts to reduce needlestick injuries in hospitals have reduced the risk to health care providers. Surgeons and other health care professionals who are infected with HIV or HCV pose a very small risk to their patients, although a number of outbreaks have been traced to surgeons who are HBV carriers; most have been Hb(e)Ag-positive.