Unit 4: Chapter 35 Flashcards
Epidimeiology
science that evaoluates occurence, deterimants, distribution and control of health and disease in a defined human population
Provides PREVENTION!!
Who was first epidimeiologist
John Snow
Looked at cholera outbreak and found it was caused by contaminated water
Compared to the 1900s, the 2000s have
more cancer and metabolic syndrome
reduced infectious disease
What organizations help develop and carry out disease prevention and control?
CDC and WHO
Why do we now have reduced infectious disease compared to the 1900s?
- public health measures
- antibiotics
- vaccine
- chlorination of drinking water system
- education
Sporadiac disease
occurs occasionally or at irregular intervals in human population
Ex. tentanus, rabis, meningitis
Endemic disease
maintains steady, low level frequency at moderately regular interval
Ex. common cold and malaria
Epidemic
outbreak affecting many people at once
Hyperendemic disease
increase in frequency above endemic level but not to epidemic level
Outbreak
very suden unexpected occurence of disease
usually in limited segment of population!!
Reservoir host
organism remains healthy while virus thrives
Index Case
first person identified in an epidemic
Pandemic
increase in disease occurence within a large population over at least 2 countries around the world
Ex. Covid19
____ determine risk factors
statistics
Incidence
measure occurence of new cases of a disease during defined period of time , as compared to total healthy population
Infectious disease frequency is important parameter for epidemiologists. In order to measure infectious disease frequency, several measurements are needed such as:
- knowledge of population
- exposed people
- affected people
Prevalence Rate
Total number of cases (individuals effected) over total population
Morbidity rate
Number of new cases of a disease during specific period over total number of individuals in population
Mortality rate
number of deaths of given disease over size of total population with disease
Communicable disease
can be transmitted from person to person
Propagated epidemic
one infected individual placed in susceptible population
long time, stabilize
Ex. strep throat
Common source epidemic
noncommunicable and results from single, common source
short time, rapid peak
Ex. food poisoning
Is influenza epidemic common source or propagated epidemic?
propagated epidemic
Time 0 of epidemic
all individuals susceptible to hypothetic pathogen
Day 15 of epidemic
epidemic peak reached
threshhold density
If the number of cases increase, the number of susceptibles
decrease
Herd immunity
threshold percentage of population having immunity so when isolated cases reemerge, there is no escalation of disease through population
Basic reproduction number (R0)
Capacity of infectious agent to spread
R0=12 meaning
For every 1 infected up to 10 people
Global pandemic
new, reemerging or drug resistant infection have increased within past 3 decades
Ex. TB, MERS
Category A pathogen
highest threat to public health
Category B pathogen
second highest threat to public health
Category C pathogen
third highest threat to public health
Systematic epidemiology
fcouses on ecological and social factors that influence development of emerging and reemerging diseases
COMBINATION
Reasons for increase in emerging/ reemerging infectious diseases
- World population growth and urbanization
- Crowded workplaces and public transportation
- Increased internal travel
- Climate change
many hospital strains are
antibiotic resistant
Nonsomical infections also health care infections
infections acquired by patients while in hospital
Endogenous sources
from normal flora (yourself)
Ex. infections and pneumonas
Exogenous sources
from outside
Ex. staff, patients, flowers
Prevention adn control of epidemics
- reduce or elimate source or reservoir of infection
- reduce number of susceptible individuals and raise general level of herd immuntiy
Impact of healthcare infections (HAI) lead to
prolong hospital stays and deaths
Choosing biological agents as weapons that favor use:
invisible, odorless, tasteless
