(LE3) Epidemiology Flashcards
What are predisposing factors for infectious disease?
Factors that increase susceptibility to disease
- immunocompromised (chemotherapy, stress, autoimmune disorders)
- trauma
- lack of herd immunity
What is epidemiology?
study of how disease spreads and effective preventative measures
Who was the first to study epidemiology?
John Snow in the 1854 cholera epidemic in London
What is incidence when referring to disease in a population?
Number of new cases during a specific time period
- measures “catching the disease”
What is prevalence when referring to disease in a population?
Total number of cases in a population at any given time
- measures “having the disease”
Define endemic
Disease is always present in a population, relatively stable incidence and prevalence
- seasonal variation is common
Define epidemic
Rapid increase in incidence in a specific area/population
- large number of cases
What is a pandemic?
worldwide epidemic
What are sporadic outbreaks?
infrequent outbreaks
- can be smaller or bigger epidemics
What are common source outbreaks?
all victims encounter the same source of disease
- outbreak develops quickly
What are propagated outbreaks?
Develops more slowly as the disease moves from host to host. No common source
What are descriptive studies?
Investigate actual outbreak and collect data
What are analytic studies?
Take the data from descriptive studies and analyze them to determine the etiology.
Two types:
1. Case-control study
2. Cohort study
What is a case-control study?
Study that looks at cases (individuals) who have the disease or outcome of interest, compare them to a control group, and look retrospectively to determine exposure levels or risk factors
What is a cohort study?
Study that takes a group with exposure and a group without exposure to source of disease and follows the groups over time and observe the outcomes
What are experimental studies?
Microbiology of pathogen, preventative measures, etc.
What is public health?
promotes and protects the health of people and communities through education, policy-making, and research
What are emerging infectious diseases? Provide some examples
New diseases with incidence on the rise
- HIV/AIDS
- SARS
- H1:N1 “swine flue”
- COVID-19
What factors influence emergence of new pathogens, or re-emergence of older pathogens?
- changes in reservoir, vector
- faster transportation
- ecological changes/disasters
- public health failures
Give an example of how changes in reservoir or vector affect emerging infectious diseases
Global warming causing rise of Anopheles mosquitos increasing incidence of Malaria
Give an example of how faster transportation affects emerging infectious diseases
HIV from Africa -> Haiti -> North America
Give an example of how ecological changes/disasters affect emerging infectious diseases
Cholera in Haiti after an earthquake
Give an example of how Public health failures affect emerging infectious diseases
- Cryptosporidiosis outbreak in Milwaukee
- E. coli outbreak at Chipotle
What are the two most common nosocomial infections, and what are their portals of entry?
E. coli: Urinary tract infection (foley catheter)
S. aureus: Surgical wounds
