Lec 01 Overview and Epidemiology of Infectious Diseases Flashcards Preview

OS 217 Infectious Diseases > Lec 01 Overview and Epidemiology of Infectious Diseases > Flashcards

Flashcards in Lec 01 Overview and Epidemiology of Infectious Diseases Deck (19)
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How is IDS epidemiology different from epidemiology in general?

* a case can also be an exposure to other patients
* subclinical infections influence epidemiology because they affect transmission
* contact patterns play a major role
* immunity plays a role
* there can be urgent and emergent situations at different levels


Infectious diseases, as a whole, is the leading cause of mortality worldwide. (T/F)



What demographics are disproportionately affected by infectious diseases?

young, elderly, people from low-income countries


What is the rank of the country in terms of TB prevalence?



What conditions facilitate the spread of infectious diseases?

* globalization of food supply
* overuse of antibiotics
* growth of mega-cities
* increasing proximity to disease vectors
* climate change
* transborder spread of diseases


How are infectious diseases classified?

* established infectious diseases
* newly emerging infectious diseases
* reemerging infectious diseases


What is colonization?

* presence of organism in the tissues without clinical and subclinical infection
* no signs and symptoms and no inflammatory response but the organism can replicate and organisms can be recovered by culture


What is a carrier?

* individual colonized with organisms but shows no evidence of disease
* able to transmit the organism


What are the components of the infectious disease triad?

host, agent, environment


What conditions are necessary for an agent to be considered epidemiologically important?

* can be transmitted through the environment
* causes infection
* produces clinical disease


What is infectiousness?

relative ease by which an agent is transmitted to other hosts


What are the determinants of infectiousness?

* characteristics of the portals of entry and exit
* agent's ability to survive away from the host
* ability to infect nonhuman hosts


How do you compute for the Reproductive Number?

P x C x D
P - probability of transmission per contact
C - contacts per unit
D - duration of infectiousness


What is infectivity?

* capability of the agent to enter, survive, and multiply in the host
* measured by the secondary attack rate


How do you compute for the secondary attack rate?

number of infected/number of susceptible and exposed


What is pathogenicity?

* extent to which overt disease is produced in an infected population
* number of patients with clinical disease/total number of infected


What are the patterns of disease occurrence?

sporadic, endemic, hyperendemic, epidemic, pandemic


What are the three main modes of transmission?

point-source outbreak, person-to-person outbreak, continuous-source outbreak


What are the characteristics of the epidemic curve of a point-source outbreak?

abrupt onset and gradual descent with a single peak