Lesson 2: History and Achievements of Epidemiology Flashcards
Who started Epidemiology 2,500 years ago?
Hippocrates
What did Hippocrates try to do?
Hippocrates attempted to explain disease occurrence from a rational viewpoint rather than supernatural viewpoint
What was hippocrates’ epidemiological work called and what did he suggest in it?
“On Airs, Waters and Places” he suggested that environmental and host factors such as behaviors, might influence the development of disease
Who was John Graunt?
A London Haberdasher and councilman. He published landmark analysis of mortality data in 1662.
John Graunt’s publication was the first to…
quantify patterns of birth, death and disease occurrence.
What did John Graunt’s publication note?
disparities between males/females (person), high infant mortality, urban/rural differences (place), and seasonal variations (time).
Who is considered the father of modern vital statistics and surveillance?
William Farr
What did William Farr do?
He developed many of basic practices epidemiologists use today, he built upon the work of John Graunt by systematically collecting and analyzing Britain’s mortality statistics.
Who is considered the father of the field of epidemiology?
John Snow
What year was John Graunt active in?
1662
What year was William Farr active in?
1800
What year was John Snow active in?
1854
What disease did Snow study?
Cholera - to discover the cause of disease and to prevent recurrence
What was John Snow’s first study?
he traced the death due to cholera and other factors and noticed a trend between the household’s water source and cholera. He linked it to a specific water well. Used 1854 data.
What was John Snow’s second study?
He used 1852 data and compared the incidence of cholera and which water company a household got their water from. Places serviced by downstream providers had higher incidences of cholera than those serviced by upstream providers.
What happened in epidemiology during the mid/late 1800s
- epidemiological methods began to be applied in the investigation of disease occurrence
- more people focuses on acute infections and diseases
- it became common practice to compare rates of disease in subgroups of the human population in the 19th century
What happened in epidemiology between the 1930s to 1940s?
Epidemiologists extended their methods to noninfectious diseases
What happened in epidemiology in the 1950s?
Richard Doll and Andrew Hill established the association between smoking and lung cancer
What happened in epidemiology between the 1960s to 1970s?
Epidemiologists accomplished unprecedented eradication of naturally occurring smallpox
What happened in epidemiology in the 1980s
Epidemiology was extended to studies of injury and violence
What did Richard Doll and Andrew Hill do? When?
They studied the relationship between tobacco use and lung caner. This was during the 1950s
What was a correlation discovered by Richard Doll and Andrew Hill
Male doctors born between 1900-1930 who smoked cigarettes died, on average, about 10 years younger than lifelong non-smokers
when the the related fields of molecular genetic epidemiology take root?
1990s
What does molecular epidemiology do?
It measures exposure to specific substances and early biological response
what is genetic epidemiology?
it deals with the etiology distribution and control of disease in groups of relatives and with inherited causes of disease in populations
Genetic epidemiology establishes…
- a genetic component to the disorder
- the relative size of that genetic effect in the relation to other sources of variation in disease risk
- the responsible gene(s)
What are public health genetics?
the application of advances in genetics and molecular biotechnology to improve public health
What does public health include?
- population screening programs
- organizing and evaluating programs
- organizing and evaluating services for patients with genetic disorders
- the impact of genetics on medical practice
When was the eradication of smallpox?
1980
when was the cowpox infection found to have protection against the smallpox virus?
1790s
What parts of epidemiology were central to the eradication of smallpox?
- Providing information about the distribution of cases and the model mechanisms and levels of transmission
- Mapping outbreaks of the disease
- evaluating control measures
What aspects of smallpox made it easy to eradicate?
- there was no animal host
- and low average number of secondary cases
When was the ten-year smallpox eradication programme implanted by the WHO
1967
When was small pox eradicated?
May 8th 1980
What features of smallpox were determined using epidemiological methods
- there are no non-human hosts
- there are no subclinical carriers
- recovered patients are immune and cannot transmit the infection
- naturally occuring smallpox does not spread as rapidly as other infectious disease such as measles or pertussis
- transmission is generally via lon-lasting human-human contact
- most patients are bedridden when they become infectious which limits transmission
Mercury became a symbol of…
the dangers of environmental pollution
In the 1950s what happened in regards to methylmercury poisoning
Mercury compounds were released with the water discharged from a factory in Minamata Japan into a small bay
What happened after the methylmercury was released?
It led to an accumulation of methylmercury in fish, causing severe poisoning in people who ate the fish.
What was the first known outbreak of methymercury poisoning
Minamata Japan Bay. It was also one of the first reported epidemics of disease caused by environemntal pollution
What is Rheumatic fever associated with?
It is associated with poverty, in particular poor housing and overcrowding. These conditions favor the spread of streptococcal upper respiratory tract infections
What is the state of rheumatic fever right today?
It has almost dissapeared from most high-income countries but pockets of relaticely high incidence still exist among socially and econominally isadvatanged populations
What does Iodine Deficiency Disease cause?
a losss of physical and mental energy associated with inadequate production of the iodine-containing thyroid hormone
Where does Iodine deficiency disease commonly occur?
certain mountainous regions
When was the goitre and cretinism were first describedin detail?
Roughly 400 years ago
What happened in 1915 in relation to Iodine Deficiency Disease?
In 1915, endemic goitre was named as the easiest known disease to prevent and use of iodized salt for goitre control was proposed the same year in Swizterland
When was iodized salt introduced on a community scale in many coutries?
1924
Why is the use of iodized salt effective?
it is effective because salt is used by all classes of society at roughly the same level throughout the year.
What was the firs larg-scale trial with iodized salt?
In ohio USA, on 500 grils between 11 and 18 years old
When was the dramtic increase on lung cancer and in what population?
In the 1930s initially in men
What is the main cuase of lung cancer death rates
tobacco use
t are other exposures that contribute to the increased lung cancer burden
asbestos dust and urban eai pollution
How does the risk of hip fractures increase
with age as a result of age-related decreased bone mass at the proximal femur and age-related increase in falls
Wen was the acquired immunodefiency syndrom firs identified as a distinct disease entity?
1981 USA
How many people were estimated to have human immunodefiency virus by 1990
10 million people
What has the state of HIV and AIDS been since 1990?
- 25 million people of died of AIDS
- and a further 40 million have been infected with HIV
- THIS MAKES IT ONE OF THE MSOT DESTRUCTIVE INFECTIOUS DISEASE EPIDEMICS IN RECORDED HISTORY
What is the distribution of AIDS cases in the world?
- 95% occured in low/middle income countries
- 70% occuring in subSaharan AFrica
- 20% in Asia
What was the outcome of SARS?
more than 8000 cases and approximately 900 deaths in 12 countries
