MT2 > Basic Concepts in Epidemiology Flashcards
What definition describes the “incidence” of a disease?
The rate of development of a disease in a group over a period of time.
What definition describes the “prevalence” of a disease?
The number of people who have the disease at a certain point in time.
What is an example which uses the term “incidence” in relation to disease?
The incidence of myocardial infarction is about 1% per year in men aged 55-59 in our community.
What is an example which uses the term “prevalence” in relation to disease?
The presence of diarrhea in the children’s camp on July 13th was 33%.
What scale is used when talking about prevalence rates? What about incidence rates?
Prevalence: rates per 10,000
Incidence: rates per 100,000
For which 3 important notifiable diseases is the incidence rate higher in BC than the Canadian average?
- AIDS
- Hepatitis C
- Pertussis
For which 2 important notifiable diseases is the incidence rate lower in BC than the Canadian average?
- Gonococcal infections
2. Verotoxigenic E. coli
What definition describes the “morbidity” of a disease? Does it refer to prevalence or incidence?
The incidence of illness (disease) in a population. Includes both fatal and nonfatal at a point in time. Can refer to either prevalence or incidence.
What is an example which uses the term “morbidity” in relation to disease?
Morbidity rate of genital Chlamydia in Canada in 2000 was 32%.
What definition describes the “mortality” of a disease?
The incidence of death in a population.
What is an example which uses the term “mortality” in relation to disease?
The mortality rate varied from 25% to 33% of Europe’s population during plague epidemics in the middle ages.
What is meant by the term “Case Fatality Rate”?
An estimate of the number of deaths due to a disease based on the mortality rate of a small sample.
What is meant by a “sporadic” disease?
A disease which occurs only occasionally.
What is meant by a “endemic” disease?
A disease which is constantly present in a population.
What is meant by a “epidemic” disease?
A disease which is acquired by many people in a given area in a short time.
What is meant by a “pandemic” disease?
A worldwide epidemic.
What is meant by an “acute” disease?
A disease in which symptoms develop rapidly but the disease lasts only a short time.
What is meant by a “chronic” disease?
A disease in which symptoms develop slowly.
What is meant by a “subacute” disease?
A disease in which the severity is intermediate between acute and chronic.
What is meant by a “latent” disease?
A disease in which the causative agent is inactive for a time but then activates and produces symptoms.
What is meant by “herd immunity”?
Immunity in most of the population can prevent those with out immunity by limiting transmission of a disease.
What is meant by a “local” infection?
An infection in which the pathogen is limited to a small area of the body.
What is meant by a “systemic” (or “generalized”) infection?
An infection in which the pathogen has spread to the entire body.
What is meant by a “focal” infection?
A systemic infection which began as a local infection.
Define sepsis.
A toxic inflammatory condition arising from the spread of microbes from a focus of infection.
Define bacteremia.
Bacteria in the blood.
Define septicemia.
Aka: blood poisoning. The growth of bacteria in the blood.
Define toxemia.
Toxins in the blood.
Define viremia.
Viruses in the blood.
Define a primary infection.
An acute infection which causes the initial illness.
Define a secondary infection.
An opportunistic infection which follows a primary infection.
Define a subclinical disease.
An infection which produces no noticeable signs or symptoms.
List some predisposing factor which can in some cases make the body more susceptible to disease.
- Gender
- Inherited traits (ex: anemia)
- Climate and weather
- Fatigue
- Age
- Lifestyle
- Nutrition
- Chemotherapy
Describe the “incubation period” of a disease.
The interval between the initial infection and the first signs and symptoms.
Describe the “prodromal period” of a disease.
The short period after incubation in which the patient presents with early, mild symptoms.
Describe the “period of illness” of a disease.
The period during a disease’s progression in which the symptoms are most severe.
Describe the “period of decline” of a disease.
The period after maximum severity in which signs and symptoms subside.