Communicable Diseases Flashcards
What is a cluster in terms of disease incidence?
An unusually high incidence of disease in a certain place and time
A cluster of cases could be due to chance or could be the beginning of an outbreak.
Define epidemic.
Occurrence of more cases of disease than expected in a given area or among a specific group
What is the difference between an outbreak and an epidemic?
Outbreak refers to a disease in excess of what would normally be expected in a defined community, while epidemic is a broader term for increased cases in a specific area.
What does a multi-jurisdictional outbreak refer to?
An outbreak in which the infection is spread over more than one geographic jurisdiction and/or involves multiple agencies.
What is an epizootic?
An epidemic affecting animals
Define pandemic.
An epidemic occurring over a wide area, crossing international borders, and affecting a large number of people
Provide examples of pandemics.
- 1918 Spanish influenza
- 2009 H1N1 influenza
- COVID-19
What does endemicity refer to?
Constant presence of a disease within a given geographic area or population
Define holoendemic.
An endemic disease for which the infection usually occurs in childhood and is less common in adults.
What characterizes a hyperendemic disease?
An endemic disease that is highly prevalent and affects all age groups equally.
What is an enzootic?
An endemic affecting animals
Define emerging infectious disease.
Infectious disease with a novel range, host, or mode of transmission
What are factors driving emerging infectious diseases?
- Microbial resistance
- Climate change
- International travel
- Poverty
- War
- Changes in land use
- Human susceptibility
- Human/vector/reservoir migration
- Population growth
What is the difference between newly emerging and re-emerging infectious diseases?
Newly emerging diseases are newly recognized in human hosts, while re-emerging diseases have historically infected humans but are now appearing in new locations or forms.
Define synergistic epidemic or syndemic.
Interaction of co-present or sequential diseases with social and environmental factors that enhance negative effects.
What are zoonotic diseases?
Infectious diseases that can spread from animals to people
What does epidemiologic silence refer to?
Lack of reported human disease due to low transmission, high immunity, or failure of surveillance systems.
What is the latent period?
Interval between initial contact with an infectious agent and the beginning of the communicable period.
Define incubation period.
Interval between initial contact with an infectious agent and the first appearance of symptoms.
What is the communicable period?
Interval during which a case is infectious.
What is the symptomatic period?
Period during which infected individual is symptomatic.
What is generation time in epidemiology?
Time from infectiousness in the first case to infectiousness in the second case.
Define serial interval.
Time from onset of symptoms in the first case to onset of symptoms in the second case.
What is surveillance in the context of public health?
Ongoing systematic collection, analysis, interpretation, and evaluation of health data.
What are the objectives of a surveillance program?
- Guide health interventions
- Estimate trends
- Identify high-risk groups
- Monitor changes in transmission patterns
- Evaluate prevention strategies
- Suggest hypotheses for further research
