Encyclopedia of Health and Medicine

opportunistic infection 347
cannot distinguish between normal flora and pathogenic
bacteria. So ANTIBIOTIC MEDICATIONS, particularly
broad-spectrum antibiotics, kill bacteria in the
gastrointestinal tract and the reproductive tract at
the same time they kill pathogenic bacteria. The
result may be DIARRHEA or yeast VAGINITIS.
See also FUNGUS; INFECTION.
nosocomial infections Illnesses that result from
INFECTION acquired in a hospital, skilled nursing
facility, or other health-care facility. The PATHOGEN
is typically bacterial, viral, or fungal. Many
pathogens that cause nosocomial infections are
resistant to common methods of treatment. The
most common causes of nosocomial infections are
• invasive procedures ranging from intravenous
(IV) lines and urinary catheters to surgery
• environmental factors such as air-conditioning
and heating systems that harbor and distribute
pathogens
• poor hygiene practices by staff (inadequate
HAND WASHING, improper disposal of contaminated
items)
• inappropriate separation of patients (such as
medical patients roomed with surgical patients)
The risk for acquiring a nosocomial infection
correlates directly to the length of time the person
remains in the hospital or care facility—the longer
the stay, the greater the risk. About 2 million people
acquire nosocomial infections in the United
States each year. Prevention efforts include
improved infection control procedures and education
for hospital and care facility staff.
See also ANTIBIOTIC RESISTANCE; BACTERIA; FUNGUS;
LEGIONNAIRES’ DISEASE; OPPORTUNISTIC INFECTION;
VIRUS.
opportunistic infection Illness that develops in a
person who is IMMUNOCOMPROMISED as a result of
exposure to an otherwise benign MICROBE or a
PATHOGEN a healthy IMMUNE SYSTEM could contain or
eradicate. Opportunistic infections commonly
occur in people who have HIV/AIDS, are receiving
IMMUNOSUPPRESSIVE THERAPY after ORGAN TRANSPLAN-
TATION, or are undergoing certain kinds of treatment
for cancer. The weakened state of the
IMMUNE SYSTEM allows infections to take hold as
well as makes fighting the INFECTION more difficult.
COMMON OPPORTUNISTIC INFECTIONS
CANDIDIASIS
HERPES SIMPLEX infection
CRYPTOCOCCOSIS
TOXOPLASMOSIS
See also NOSOCOMIAL INFECTION.
CYTOMEGALOVIRUS (CMV) INFECTION
COCCIDIOIDOMYCOSIS
Pneumocystis carinii PNEUMONIA
TUBERCULOSIS