Postexposure prophylaxis for common infectious diseases.

Postexposure prophylaxis (PEP) is effective in preventing illness after potential or documented exposure to a variety of microbial pathogens and in reducing the risk of secondary spread of infection. Guidelines have been published by the Centers for Disease Control and Prevention and the Advisory Committee on Immunization Practices for proper use of PEP for bloodborne pathogens, for microorganisms transmitted by either airborne or droplet spread or through direct contact, and for infections acquired after traumatic injuries. Depending on the type of exposure, different forms of PEP are available, including vaccines, immune globulins, antibiotics, and antiviral medications. Physicians should assess a patient's potential need for PEP based on several factors, including the type of exposure, the timing and severity of illness in the source patient, the exposed person's susceptibility to infectious diseases of concern, and the relative risks and benefits of the PEP regimen in an individual situation. Immunity to certain infectious diseases can be ensured with prior infection or vaccination, and by serologic testing in patients with a negative or uncertain history. PEP should be given to persons exposed to index cases of pertussis and invasive meningococcal infection regardless of immunization history, and should be given following rabies and tetanus exposure regardless of the length of delay. In general, PEP should be given as soon as possible following a high-risk exposure. Persons exposed to bloodborne pathogens should have baseline testing for human immunodeficiency virus, hepatitis B virus, and hepatitis C virus antibodies, and follow-up testing at six weeks, three months, and six months postexposure.