Infection Control Flashcards
What is the difference between exotoxins and endotoxins?
Exo= gram +, released from intact bacterial cells, attack a specific target tissue Endo= gram -, released from disrupted bacterial cells, generalized effects on host
What is generation time when referring to bacteria?
How long it takes for binary fission to take place, also known as the doubling time.
Name and describe the four phases of bacterial growth
Lag- cell adapts to new environment
Log- period of maximum growth
Stationary- bacteria stop growing and multiplying as supply of nutrients is exhausted
Death- cells die in their own waste or lack of nutrients
Which hepatitis are blood borne?
Hepatitis B (immunization), Hep C (no immunization)
What can HIV be spread by?
Any lymphocyte containing bodily fluid like blood, semen, vaginal secretions, breast milk.
What is a nosocomial infection?
An infection acquired in the hospital.
What are the types of nosocomial infections?
Hospital microorganisms, compromised patients, and transmission between patients
What is the bacteria causing common surgical wound infections?
S. aureus
What is the most common bacteria causing nosocomial UTIs?
E coli
What are the three elements of transmission?
A source of the pathogen, the mode of transmission, and access to a susceptible host.
What are the routes of transmission?
Contact, droplet, vehicles (ex. food), airborne, vector (ex. insect or parasite)
What is a fomite?
An object or material that has the potential to carry pathogens. ex. dirty door knob, fork, etc.
What is ventilator-associated pneumonia?
Pneumonia that occurs with endotracheal intubation.
What are some ways to avoid VAP?
Noninvasive ventilation, hand washing, elevation of the bed, change of circuits when grossly contaminated, use of heat moisture whenever possible (to keep secretions mobile, keep ventilator tubing gravity dependent, oral care, aspiration of subglottic secretions, kinetic beds
What are the portals of entry for a microorganism?
Skin, mucous membranes, placenta, parenterally (orally).
What are signs and symptoms of infection?
fever, redness, inflammation, swelling, pain, nausea, malaise, purulent exudate (pus), leukocytosis (increase in WBC count)
What are some sources of febrile heat generation?
Constriction of blood vessels, increased metabolic rate, shivering.
What compound initiates the inflammation cascade?
Histamine
What major things happen during inflammation?
Vasodilation to increase blood flow to the area and increased permeability of the vessels to allow fluid into the surrounding tissue.
What is the role of clotting factors in inflammation?
They move to the site of injury to surround and isolate the microbe.
What is the role of antibodies in inflammation?
They coat bacteria in preparation for phagocytosis or neutralize toxins.
What is the role of antigens in inflammation?
They are introduced to lymphocytes to activate antibody production.
What is the role of WBCs in inflammation?
They are attracted to the area to engulf and destroy bacteria.
What are some causes of antibiotic resistance?
Over-prescription of antibiotics, stopping taking antibiotics before completing whole course, use of antibiotics in livestock and feed
What do antiviral drugs typically target?
They target the mechanism of viral replication.
What is humoral immunity?
A type of learned immunity where specific antibodies are formed by transformed B-cells after an antigen is encountered.
What is cellular immunity?
A type of learned immunity where T-cells learn to recognize and destroy large invading microorganisms, intracellular pathogens like TB and viruses, as well as cancer cells.
Define immunization.
A process by which resistance to an infectious disease is induced or augmented.
What is an antigen?
A protein that induces a specific immune response.
What is an antibody?
A result of an immune response; proteins belonging to a group called gamma globulins, commonly referred to as immunoglobulins (Ig).
What is IgM?
An immunoglobulin (antibody) that is responsible for the first immune response and has a short life. It is present on B cells and controls B-cell activation.
What is IgG?
An immunoglobulin (antibody) that can bind to pathogens and protect against infections and toxins. It is long lasting, indicates a past exposure, and is the only antibody capable of crossing the placenta.
Describe the three steps antibody production.
Lymphocytes (T-cells and B-cells) make contact with antigen, B-cells proliferate into a clone, the clone divides into plasma cells (produce antibodies) and memory cells (do not currently produce antibodies but can be activated by a subsequent exposure.
What is the difference between active and passive immunity?
Active- exposed to antigen that triggers immune response, takes days to weeks to establish protection, long lasting immunity
Passive- acquires preformed antibodies, available immediately, immunity does not last long.
Define host.
An organism that harbors or provides nutrition to a dissimilar organism.
Define infectious disease.
Illness caused by pathogenic microorganisms
Define colonization.
The sustained presence of replicating infectious agents on or in the body without production of an immune response or disease
Define virulence.
A pathogen’s heightened ability to infect or harm a host and produce disease.
Define pathogen.
The bacteria, virus, or microorganism that can cause disease.
Define saprophyte.
Organisms that live on dead organic matter (fungi or bacteria).
Define seroconversion.
An individual who tests negative for an antibody before immunization and positive after immunization.
Define nosocomial.
A hospital-acquired infection.
Define endemic.
A disease that occurs continuously in a particular population but has low mortality (ex. measles).
Define epidemic.
A sudden or sever outbreak within a group.
Define pandemic.
When an epidemic becomes very widespread and affects the whole region, a continent, or the world
