Chapter 11

Summarize the most common healthcare-associated infections

Pneumonia, gastrointestinal illness, urinary tract infections, bloodstream infections, and surgical site infections

Define communicable, contagious, and noncommunicable

Communicable. Contagious: communicable; transmissble by direct contact w/ infected people and their fresh secretions or excretions. Noncommunicable: an infectious disease that does not arrive through transmission of an infectious agent from host to host

Define fomite, vehicle, and aerosol

Fomite: inanimate objects contaminated with the infectious organism.

Identify the portal of entry for some common disease

example: inoculation of the nasal mucosa w/the influenza virus will result in the flu, but if the virus contacts the skin, no infection occurs

Recall the pathogens have a preferred portal of entry and exit

"the majority of pathogens have adapted to a specific portal of entry, one that provides a favorable habitat for further growth and spread"

Summarize the unique factors that make some healthcare-associated infections unavoidable in hospitals

Aquire infections directly/indirectly from fomites, medical equipment, other patients, medical personnel, visitors, air, and water.

Summarize the understand Koch's postulates

1. Find evidence of a particular microbe. 2. Isolate that microbe from an infected subject and cultivate it in pure culture in the lab. 3. Inoculate a susceptible healthy subject with the lab isolate and observe the same resultant disease. 4. Re-isolate the organism identified should be exact to the one originally acquired from the host

Define virulence factor

A microbe's structures or capabilities that allow it to establish itself in a host and cause damage.

Recall the definition of adhesion, what are the limits and mechanisms

Adhesion is the process by which microbes gain a more stable foothold at the portal of entry; often involves a specific interaction between the molecules on the microbial surface and the receptors on the host cell. Limits and mechanisms

Distinguish between signs and symptoms

An objective assessment of disease is called a(n) _______, as opposed to the subjective assessment perceived by the patient referred to as a(n____) .

Know when Koch's postulates is unusable

Difficult for viral diseases because viruses usually have a very narrow host range. Some infectious agents are not readily isolated or grown in the lab. Not possible to determine causation in polmicrobial disease

Define infection, disease, infectious disease

Infection: the entry and multiplication of pathogenic organisms within a host. Disease: any deviation from health, as when the effects of microbial infection damage/disrupt tissues and organs. Infectious disease: the state of damage or toxicity in the body caused by an infectious agent.

Recall the definition of pathogen, pathogenicity, opportunistic pathogens

Pathogens: a microbe whose relationship with its host is parasitic and results in infection and disease. Pathogenicity: the capacity of microbes to cause disease. Opportunistic pathogens: in infection, ordinarily nonpathogenic or weakly pathogenic microbes that cause disease primarily in an immunologically compromised host.

Recall the definition of phagocyte

Phagocyte are a natural body defense that can engulf and destroy foreign cells through phagocytosis, thus preventing infection

Recall the definition of microbial antagonism

Relationship in which microorganisms compete for survival in a common environment by taking actions that inhibit or destroy another organism

Define reservoir, transmitter, and carrier

Reservoir: in disease communication, the natural host or habitat of a pathogen. Transmitter: Carrier: a person who harbors infections and inconspicuously spreads them to others

Recall the definition of virulence and what determines it

Virulence: in infection, the relative capacity of a pathogen to invade and harm host cells. The virulence of a microbe is determined by its ability to 1) establish itself in the host and 2) cause damage.

Recall the definition of nosocomial infection

any infection acquired as a direct result of a patient's presence in a hospital or health care setting (also known as HAI healthcare-associated infection)

Summarize the factors that weaken host defenses

old age and extreme youth, genetic defects in immunity, acquired defects in immunity (AIDS), surgery and organ transplants, underlying disease- cancer+diabetes, chemotherapy, physical+mental stress, pregnancy, other infections