epidemiology Flashcards
is the study of factors that
determine the
frequency, distribution,
and determinants of
diseases in human
populations
Epidemiology
If the infectious disease is transmissible from one human to another it is called a
communicable disease
is defined as a communicable disease that is easily transmitted from one person to another
contagious
disease
Infectious diseases that humans acquire from animal sources are called
zoonotic diseases or zoonoses
is defined as the
number of new cases of that disease in a defined population during a specific time period
incidence
expressed as the number of new cases of a particular disease that occurred during a specified time period per a specifically defined population
morbidity rate
the number of cases of the disease existing in a given population during a specific time period
period prevalence
is the number of cases of the disease existing in a given population at a particular moment in time
point prevalence
also known as the death rate is the ratio of the number of people who died of a particular disease during a specified time period
Mortality Rate
is a disease that occurs only occasionally
(sporadically) within the population of a particular geographic area
Sporadic Disease
are diseases that are always present within the population of a particular geographic area
Endemic Disease
a disease that is occurring in epidemic proportions in many countries simultaneously
Pandemic Diseases
The six components in
the chain of infection
(a) a pathogen,
(b) a reservoir of
infection
(c) a portal
of exit,
(d) a mode of
transmission,
(e) a portal of entry,
(f) a susceptible host.
The sources of microbes that cause infectious diseases are many and varied. They are known as
reservoirs
is a person who
is colonized with a particular pathogen, but the pathogen is not currently causing disease in that person
carrier
carry the pathogen without ever having had the disease.
Passive carriers
a person who is capable of transmitting a pathogen during the incubation period
incubatory carrier
harbor and can transmit a particular pathogen while recovering from an infectious disease
Convalescent carriers
carriers have completely recovered from the disease, but continue to harbor the pathogen indefinitely
Active carriers
are inanimate objects capable of transmitting pathogens. found within healthcare settings include patients’ gowns, bedding, towels, eating and drinking utensils, and hospital equipment
Fomites
The five principal
modes by which
transmission of
pathogens
direct
indirect contact,
droplet,
airborne,
vehicular vector
transmission
may be generated by coughing, sneezing, and even talking.
Droplet
involves the dispersal of droplet nuclei, which are the residue of evaporated droplets, and are smaller than 5m in diameter.
Airborne transmission
is predominantly a zoonosis and is usually
transmitted to humans by flea
Plague
All of the following are major steps in the treatment
of a community’s drinking water except:
a. boiling.
b. filtration.
c. flocculation.
d. sedimentation
a
Which of the following are considered reservoirs of
infection?
a. carriers
b. contaminated food and drinking water
c. rabid animals
d. all of the above
d
- Which of the following arthropods is the vector of
Lyme disease?
a. flea
b. mite
c. mosquito
d. tick
a
pathogens are transferred from one infected person to another person without a contaminated intermediate object or
person.
direct contact transmission
happens when pathogens
are transferred via a contaminated intermediate object
or person.
- Indirect contact transmission
respiratory droplets carrying pathogens transmit infection when they travel from the
respiratory tract of an infectious individual (e.g., by sneezing or coughing
Droplet Transmission
occurs with dissemination of either airborne droplet nuclei or small particles containing
pathogens
Airborne Transmission
pertains to the numerous measures that are taken to prevent
infections from occurring in healthcare settings
infection control
is a clean technique. Its
goal is to exclude
pathogens
Medical asepsis
kill bacterial spores with prolonged exposure times
(3–12 hours); these are referred to as
chemical sterilants.
kill all microbes (including viruses),e except large numbers of bacterial spores.
High-level disinfectants
might kill mycobacteria, vegetative bacteria, most viruses, and most fungi, but do not necessarily kill bacterial spores
Intermediate-level disinfectants
kill most vegetative bacteria, some fungi, and some viruses within 10 minutes of exposure
Low-level disinfectants
items confer a high risk for infection if they are contaminated with any microbes
include surgical instruments, cardiac and urinary catheters, implants, and ultrasound probes u
Critical Items.
items contact mucous
membranes or nonintact skin and require high-level disinfection.
therapy and anesthesia equipment, some endoscopes,
laryngoscope blades,
- Semicritical Items
items are those that
come in contact with intact skin, but not mucous
membranes.
Such items are divided into two subcategories: noncritical patient care items (e.g., bedpans,
blood pressure cuffs, crutches, computers)
Noncritical Items
includes practices
used to render and keep objects and areas sterile
Surgical Asepsis
The most important and
most basic technique in
preventing and
controlling infections
and preventing the
transmission
Hand Hygiene
is the most important and frequent mode of transmission of HAIs are used for patients known or suspected to be infected or colonized with epidemiologically
important pathogens that can be transmitted by direct or
indirect contact.
Contact Precautions
The preferred placement for patients who are infected with pathogens that are spread via airborne droplet nuclei and, therefore, require
Airborne Infection Isolation Rooms
- An HAI is one that:
a. develops during hospitalization or erupts within
14 days of hospital discharge.
b. develops while the patient is hospitalized.
c. is acquired in the community.
d. the patient has at the time of hospital admission.
a
- An example of a fomite would be:
a. a drinking glass used by a patient.
b. bandages from an infected wound.
c. soiled bed linens.
d. all of the above.
d
- A Protective Environment would be appropriate for
a patient:
a. infected with MRSA.
b. with leukopenia.
c. with pneumonic plague.
d. with tuberculosis.
b
- Which of the following is not part of Standard
Precautions?
a. handwashing between patient contacts
b. placing a patient in a private room having negative air pressure
c. properly disposing of needles, scalpels, and other
sharps
d. wearing gloves, masks, eye protection, and gowns
when appropriate
b
- A patient suspected of having tuberculosis has been
admitted to the hospital. Which one of the following is not appropriate?
a. Droplet Precautions
b. an AIIR
c. Standard Precautions
d. use of a type N95 respirator by healthcare professional who are caring for the patien
a
- Which of the following statements about medical
asepsis is false?
a. Disinfection is a medical aseptic technique.
b. Handwashing is a medical aseptic technique.
c. Medical asepsis is considered a clean technique.
d. The goal of medical asepsis is to exclude all
microorganisms from an area
d
- Which of the following statements about an AIIR is
false?
a. Air entering the room is passed through HEPA
filters.
b. The room is under negative air pressure.
c. An AIIR is appropriate for patients with meningococcal meningitis, whooping cough, or influenza.
d. Transmission-Based Precautions will be necessary
a
- Contact Precautions are required for patients with:
a. C. difficile-associated diseases.
b. infections caused by multidrug-resistant bacteria.
c. viral hemorrhagic fevers.
d. all of the above.
d
