Epidemiology Flashcards
20
What is epidemiology?
The study of the occurance, distribution, and determinants of health and disease in a population
Epidemiology is largerly linked to
public health
What is survellance in epidemiology?
The observation, recognition, and reporting of diseases as they occur
Incidence is
The number of NEW cases of the disease in a given period of time
Prevalence is
the TOTAL number of NEW AND EXISTING cases in a population in a given time
Will incidence or prevalence be larger?
Prevalence
When is a disease an epidemic?
When it occurs in a large numebr of peopel in a population at the same time
A pandemic is
widespreas, usually worldwide
What is an endemic?
A disease is constantly present is a ppoulation, usually at low incidences. Individuals that are infected with a pathogen that causes endemic diseases are celled reservoirs. These reservoirs may be human or non-human animals
When is a disease an outbreak?
A disease outbreak occurs when a number of cases of a diesease are reported in a short period of time
Diseased individuals who show no or mild symptoms have subclinical infections are are called…
carriers
Chronic infections…
Host and pathogen survive
Acute infections
Pathogen can be selective force
he organism invades and colonizes the host
infection
the time between infection and onset of symptoms
Incubation period
The disease is at its height
Acute period
Disease symptoms are subsiding
Decline period
Patient regains strength and returns to normal
Convalescent period
What is mortality?
the incidence of death in a population
What is morbidity?
the incidence of disease, including fatal and nonfatal diseases
quantitatively measures disease burden in terms of lost years due to the disease, disability due to disease, and premature death
Disability-Adjusteed Life Year (DALY)
_____ of a host and its parasite is common
coevolution
What is herd immunity?
The resistance of a group to infection due to immunity of a high proportion of the group
If a high proportion of individuals are immune to an infection, then the whole population will be protected.
Immunized people protect nonimmunized people because the pathogen cannot be passed on, and the cycle of infectivity is broken
Infected individual transmits a disease directly to a susceptible host without the assistance of an intermediary (e.g., flu, common cold, STDs, ringworm).
Direct host-to-host transmission
occurs when transmission is facilitated by a living or nonliving agent
Indirect host-to-host transmission
Living agents are called
vectors
nonliving agents are called
fomites
___ are sites in which infectious agents remain viable and from which individuals can become infected
Reservoirs
_____ is any disease that primarily infects animals but is occasionally transmitted to humans
zoonosis
A ______ usually arises from contamination of water or food
common-source epidemic
In a _____, the disease shows a slow, progressive rise and a gradual decline.
host-to-host epidemic
What is R0 (r not)
Basic reprodcution number
Food, water, and air are…
common vehicles
If reservoir is animal, it can be ____ or _____.
immunized or destroyed
When human is a reservoir, those can be…
- quarantined
- immunized
- treated
What are the three main tools for limiting transmission?
- immunization
- quarantine
- surveillance
_____ diseases are those that have become prevalent after having been under control
reemerging
Diseases that suddenly become prevalent are called ___
emergent
Direct transfer
- sex
- holding hands
- kissing
- speaking
Infirect transfer
- fomites (pens, money)
- vectors (fleas, mites, etc)
Vecotrs tend to be
arthopods (include insects)
What are the two kinds of vectos?
biological - biting transfer (mosquito bites animal and then bites you)
mechanical - not infected, but carrying disease on surface. (fly land on poop and then land on your food)
