Epidemiology, Infections and Communicable Disease Flashcards
What is the latency period?
replication before shedding
What is the interval between invasion by an infectious agent and the first appearance of S/S of disease?
incubation period
What is the interval during which an infectious agent may be transferred?
communicable period, usually starts before start of S/S
What is the incubation and communicable period for chicken pox?
- 2-3 wks
- 1-2 days before development of a rash, until lesions crust over (appx. 5 days)
Signs of a localized infection?
inflammation, redness, warmth, selling, pain/tenderness, loss of function, drainage, cellulitis
Signs of generalized infection?
weakness, HA, malaise, fever, increases pulse, hyhpotension
When are neutrophil counts increased?
in most bacterial infections
Increased eosinophils are indicative of what?
an allergic reaction
Lymphocytes are increased in which diseases?
chickenpox, mumps, measles, mono, viral hepatitis (viruses)
When will Monocytes be increased?
TB and in the convalescent phase of acute infections
What does the term “shift to the left” indicate?
active infection with an increased number of immature neutrophils
What is C-Reactive Protein an indicator of?
inflammation
Sedimentation rate is a marker of what?
inflammation and infection
What is it called when a disease or condition is regularly found in a particular area/population?
an endemic
What is a secular pattern of disease?
long-term patterns, greater than 10 yrs
What is a point epidemic?
time and space related event (ex. food poisoning at a picnic)
What is a cyclical pattern of disease?
seasonal fluctuations (flu/cold)
People having reactions to the same vaccine at different places and at different times is an example of what type of disease pattern?
Event-related cluster
What factors make up the epidemiologic triangle?
Host, Agent, environment
Definition of “agents” of disease?
causes of the disease (bacteria, poison, cholesterol)
What is a prevalence rate?
number of all cases of a specific disease at a given point in time
What is an incidence rate?
number of new cases in a population in a specified period of time
How to calculate the incidence rate?
(new cases at a specified period in time/total population at risk) x factor (1, 10, 100…)
How to calculate the prevalence rate?
(existing cases at a specified period in time/totoal population at risk) x a factor (10, 100….)
What is an attack rate?
proportion of persons exposed to an agent and who develop the disease
How to calculate the attack rate?
- (number of cases/ total population exposed) x 100
- is listed as a percentage
What is the term for the probability of an event occurring in the exposed group versus the control (non-exposed) group?
relative risk (RR)
How to calculate the relative risk?
RR = incidence of disease in exposed population/incidence of disease in non-exposed or control population
What are the stages of the natural history of disease?
1) pre-exposure (risk factors present for disease)
2) pre-pathogenesis or preclinical stage (exposure to causative agent)
3) pathogenesis (disease is present)
4) resolution (problem resolved)
Stages of HIV?
1) primary infection (< 1 month)
2) clinical latency (no symptoms)
3) symptomatic disease (AIDs)
What is the definition of sensitivity in a screening test?
quentifies ho accurately the test identifies those WITH the condition or trait (true positives)
What is the definition of specificity in a screening test?
indicates how accurately the test identifies those WITHOUT the condition or trait (true negatives)
How is the validity of a screening test measured?
by specificity and sensitivity
What is Latency in disease development?
replication before shedding
What is the interval between invasion by an infectious agent and the first appearance of signs and symptoms?
incubation period
What is the interval during which an infectious agent may be transferred?
communicable period - usually starts before s/s present
Which WBC is increased in most bacterial infections?
neutrophils
Which WBC is increased during an allergic reaction?
eosinophils
A patient presents with a viral infection, which WBC would you expect to increase in number?
lymphocytes
The term for an infectious agents ability to produce an immune response?
antigenicity
What is the difference between pathogenicity and virulence?
Pathogenicity Is the microbes ability to cause disease and virulence refers to the severity of the disease
TB stats:
1) infectivity
2) pathogenicity
3) virulence
1) low
2) low
3) high
Routes of horizontal transmission of disease?
1) direct/indirect
2) common vehicle (water, food)
3) airborne
4) vectorborne
What is a fomite?
an inanimate object that is able to carry infectious agents (clothes, toys)
Transmission-based Precautions - Airborne?
used with pathogens smaller than 5 microns & droplets or dust particles suspended in air; private room with monitored negative air pressure; door closed; mask for transport; wear N-95 HEPA filter or fit-test respirator mask
Transmission-based Precautions - dropplet?
used with pathogens transmitted by infectious droplets; droplets larger than 5 microns; private room, can leave door open; mask for transport
Airborn precautions used for which diseases?
measles (rubeola), TB, Varicella, shingles
Dropplet precautions used for which disease?
diphtheria, pneumonia, meningitis, rubella, mumps, pertussis
Transmission-based Precautions - Contact?
needed with physical skin-to-skin contact; private room; clean, non-sterile gloves and gown (remove before leaving pt. room), dedicated equipment
Transmission-based Precautions - Neutropenic?
to prevent infection among clients with immunosuppression
Contact precautions used for which diseases?
MRSA, herpes, clostridium difficile, RSV, pediculosis, scabies, excess wound drainage, fecal incontinence, rotavirus, Hep A
Passive vs Active immunity?
passive is given to the patient (mom to baby), active is produce by the patients own body
The bacterium Yersinia pestis is resonsible for causing what disease?
plague
Recommended routine childhood immunization schedule in U.S.
Hepatitis B, diphtheria, tetanus, pertussis, Haemophilus influenzae type B meningitis, Streptococcus pneumoniae-related illnesses, polio, measles, mumps, rubella, varicella, rotavirus, Hepatitis A, influenza, HPV and meningococcal disease
Overall contraindications to immunizations:
- Severe febrile illness
- Live viruses should not be given to anyone with altered immune system
- Previous allergic response to vaccine
- Recently acquired passive immunity i.e. blood transfusion, immunoglobulin
an acute, highly contagious disease with symptoms of high fever, sneezing and coughing, conjunctivitis, small white spots on the inside of the cheek (Koplik’s spots), red, blotchy rash
measles
- a virus that causes a mild febrile disease with enlarged lymph nodes and a fine, pink rash that is often difficult to distinguish from measles or scarlet fever
Rubella (german measles)
How is pertussis transmitted?
airborne droplets
a bacterial disease characterized by sudden onset (within 48 hours) of headache, abdominal pain, diarrhea, nausea, sometimes vomiting, and almost always fever; dehydration may be severe
salmonellosis
What is the most common waterborne viral agent?
Hep A
Waterborne bacterial diseases?
are cholera, typhoid fever, and bacillary dysentery
Clinical signs of Rocky Mountain Spotted fever?
sudden onset of moderate to high fever, severe headaches, chills, deep muscle pain, and malaise
What is the most common vectorborne disease in the U.S.
lyme disease
What is the characteristic sign of lyme disease?
bull’s eye skin lesion
Stages of Lyme disease?
1) responds to tetracycline or PCN
2) skin lesions,HA, neuro changes
3) arthritis or arthralgia
What is Zoonosis?
an infection transmitted under natural conditions from a vertebrate animal to a human
Examples of zoonotic diseases?
West Nile virus, monkey pox, hantavirus, mad cow, rabies
1st AIDs case was identified in what year?
1981
Common symptoms of TB?
Cough, fever, chills, fatigue, hemoptysis, chest pain, weight loss, night sweats, loss of appetite
TB is more common in which ethnic groups?
Asian and Hispanic/Latino groups
How many casualties are needed for a mass casualty and multiple casualty classifications?
- 100 or greater
- 2-99
Characteristics of Disasters?
- frequency, or how often
- predictability
- preventability
- Imminence or speed of onset
- Scope or geographic area affected and number of casualties
- Intensity or level of destruction
Components of the Disaster Management Cycle?
prevention, mitigation, preparedness, response and recovery
How often is the National Health Security Strategy (NHSS) revised?
q 4 yrs
What is the National Incident Management System (NIMS)?
the nations’ common platform form disaster response
What does the acronym “START” stand for in a triage situation?
Simple Triage And Rapid Treatment
What do the following colors mean in a disaster triage situation:
1) green
2) yellow
3) red
4) black
1) minor (ambulatory)
2) delayed
3) immediate
4) expectant
What are the criteria for an immediate (red) classification during triage?
- RPM-30-2-Can Do
Resp (30 > RR), Perfusion (cap refill > 2 secs), Mental Status (can’t follow commands)
Stages of Community Reactions?
1) heroic
2) honeymoon phase
3) disillusionment
4) reconstruction
When people notice help may not be coming and begin to despair characteristic of which community reaction stage?
disillusionment
What is the honeymoon phase following a disater?
people rejoice becasue they have survived
During a flood, Chuck sees a child struggling to hold on to a fallen tree and may drown. He jumps in and saves the child. Which community reaction is chuck displaying?
heroic
What ist hardest part of a disaster?
recovery
What is therole of public health nursing in disaster recover?
- ongoing community assessments
- comunity resilience
- pyschosocial support
