Chapter 2 Flashcards
Modes of Transmission of a disease (Host, vector, agent, and environment)
Diseases that result from an interaction of some kind
Host
a person
The agent
the bacterium
environment
contaminated water supply
Vector
mosquito or deer tick is often involved
Direct Transmission of a disease
direct contact (person to person)
human susceptibility determined by
determined on genetic background, nutritional characteristics, and immunologic characteristics
Indirect transmission
through a common vehicle such as contaminated air or water supply or a vector like a mosquito
Single exposure
happens once
Multiple exposure
happens more than once
Continuous exposure
periodically happens
Epidemic
The occurrence of a disease that affects communities or regions (more scarce)
Endemic
The occurrence of a disease that is habitually present (more common) in a geographic area
Pandemic
Worldwide
Herd Immunity
the resistance of a group of people to an attack by a disease to which a large proportion of the members of the group are immune
Attack Rate→ Page 30
of people at risk in which a certain illness develops within
________________________________________
Total number of people at risk
Person-time
The Amount of time an individual spent contributing to a study before they developed the disease.
Case-fatality
the proportion of people who develop the disease, who then die from the disease
Outbreak Investigation
- Define the outbreak and validate the existence of the outbreak
- Examine the distribution of cases
- Look for combinations of relevant variables
- Develop hypothesis
- Test hypothesis
- Recommend control measures
- prepare a written report of findings
- communicate findings
Incubation period
how long it takes for symptoms of a disease to show up
Non-clinical Diseases (be familiar with types)
Preclinical, Subclinical, Persistent, and Latent
Preclinical
Disease that is not yet clinically apparent but is destined to progress to a clinical disease
Subclinical
disease that is not clinically apparent and is not destined to come clinically apparent
Latent
an infection with no active multiplication of the agent
Persistent
A person fails to “shake off” the infection and it persist for years at times for life
Clinical diseases
Characterized by signs and symptoms
Carrier Status
an individual who harbors an organism but is not infected by evidence of clinical studies
Cross Tabulation
very helpful method to determine which agents cause a disease
