Epidemiology Flashcards
epidemiology definition
study of disease in populations
what was the first modern epidemiology study
1854 Cholera Outbreak
what led to this outbreak
poor sanitation/no sewer system
humors definition
the idea that there are four fluids in the body which must be in balance
what are the four humors
yellow bile
black bile
phlegm
blood
miasma definition
people get sick because of unclean environment and foul air
Germ Theory defintion
disease is caused by pathogen
who worked on the 1854 Cholera Outbreak
John Snow
who was John Snow
surgeon-apothecary who had experience with previous cholera outbreaks and suspected the water supply; published a call to arms in 1849 about cholera
what years did the 1854 Cholera Outbreak occur
1853-1855
incidence definition
number of new cases in a specific time
where did John Snow identify the outbreak to have started
the Broad Street water pump
who was Reverend Henry Whitehead
minister of local church looking for evidence against the water pump theory for the cholera outbreak
what did Reverend Henry Whitehead find about the pump and cholera
houses using the Broad Street pump were 9x more likely to have victims
who did Reverend Henry Whitehead identify has “patient zero”
an infant who had died two days before the outbreak from diarrhea; the infected feces seeped through cracks in basement foundation and contaminated water
why is cholera important
it was the first pathogen with a defined source of infection
common source epidemic definition
numerous individuals infected from same original source (usually breakdown in sanitation)
host-to-host epidemic definition
disease transmitted from infected to uninfected individual
epidemic threshold definition
differs from pathogen to pathogen
epidemic threshold factors
how easily is it spread
how contagious is it
symptoms
vaccines
circumstances
measles
viral infection in children that is highly contagious
MMR vaccine
influenza
RNA virus with segmented genome
have hemagglutinin and neuraminidase proteins
types of influenza
A, B, and C
hemagglutinin proteins
attach to cell
H1 through H16
neuraminidase proteins
used for escape
N1 through N9
antigenic drift definition
slow accumulation of mutations via replication
antigenic shift definition
reshuffling of genetic material
is antigenic drift or antigenic shift more dangeroys
antigenic shift
case definition
list of common symptoms developed by doctor and patient reports
characteristics of a case
time
place
personal
time characteristic
when people are getting sick
place characteristic
where individuals live, and where they are getting sick
personal characteristic
who is getting sick (age, sex, cultural background, etc)
case-control study
determine what factors link affected individuals and distinguish them from unaffected individuals
types of emerging and re-emerging diseases
- invasion of a new host population by known pathogen
- appearance of completely new, previously unknown pathogen
- association of a well-known disease with a new pathogen
- increased virulence or a newed problem with a well-known pathogen
example of the invasion of a new host population by a known pathogen
zika virus
zika virus
first isolated in monkeys in Uganda in 1947, had outbreaks in mid 2000s and early 2010s
causes microcephaly
vector: aedes mosquito
example of the appearance of a completely new, previously unknown pathogen
ebola
ebola
first cases in 1976 in Congo and Sudan, causes hemorrhagic fever and has a high mortality rate (90%)
vector: bats?
new medication and vaccines since 2013-2014 outbreak
example of an association between a well-known disease and a new pathogen
gastric ulcers caused by Heliobacter pylori
examples of increased virulence or a renewed problem with a well-known pathogen
re-emerging diseases
multi-drug resistance
