Facts on File Encyclopedia of Health and Medicine

cannot distinguish between normal flora and path-
ogenic bacteria. So ANTIBIOTIC MEDICATIONS, particu-
larly 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 DIARRHEAor 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 contami-
  nated 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 peo-

ple acquire nosocomial infections in the United

States each year. Prevention efforts include

improved infection control procedures and educa-

tion 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 IMMUNOCOMPROMISEDas a result of

exposure to an otherwise benign MICROBE or a

PATHOGENa healthy IMMUNE SYSTEMcould contain or

eradicate. Opportunistic infections commonly

occur in people who have HIV/AIDS, are receiving

IMMUNOSUPPRESSIVE THERAPYafter ORGAN TRANSPLAN-

TATION, or are undergoing certain kinds of treat-

ment for cancer. The weakened state of the

IMMUNE SYSTEMallows infections to take hold as

well as makes fighting the INFECTIONmore difficult.

COMMON OPPORTUNISTIC INFECTIONS

CANDIDIASIS CYTOMEGALOVIRUS(CMV)INFECTION

HERPES SIMPLEXinfection COCCIDIOIDOMYCOSIS

CRYPTOCOCCOSIS Pneumocystis cariniiPNEUMONIA

TOXOPLASMOSIS TUBERCULOSIS

See also NOSOCOMIAL INFECTION.

opportunistic infection 347