Lecture 5 Flashcards
industrial revolution led to…
demographic change
Problems from demographic changes
- accumulation of sewage
- gray water
- garbage
- provision of clean water, food, energy
SANITARY
What are solutions for the masses
- hospitals
- public health campaigns
potential solutions for sanitary problems
management systems = sewers, garbage, clean water supply
true or false hospitals contributed to outbreaks of highly virulent strains of viruses
true
what gave epidemiology as one of the main components of modern health sciences
outbreaks of infectious diseases
- emergence of medical maths establish epidemiology as a field
When were hospitals emerged
1800s
Important figure for evolution
Darwin
What is epidemiology
discipline that studies causes of disease looking at WHO is affected, WHERE diseases occur, WHEN they occur and the social, environmental, and lifestyle correlates of disease occurrence
What is disease
“biomedical measurable lesion, or an anatomical or physiological ‘irregularity’”
What is the traditional biomedical approach
dichotomous - healthy or sick
what are some ways to measure disease
- suffering
- statistical deviance
- physical lesion
often correlate but are not sufficient to diagnose a disorder
What are defences
symptoms like cough or fever are not defects but are the body’s defences in action
What is the smoke detector principle
better to take action, because not doing so will have very bad repercussions
do traits evolve for to or because
because
for or to insinuate there is a greater purpose of evolution, when it is really just a process
What are the main categories of illness experiences
- somatic experiences
- mental dysfunction
- suffering due to misfortune
does the carrier of illness have to be the one suffering
NO
- on occasion illness can be associated with higher reproductive success
what is psychopathies
- deceitful and manipulative
- superficial charm but lack empathy…
What is natural fallacy
- the idea that something is natural it is good
WRONG
not just because it’s natural, doesn’t mean it’s good
Most traditional approach to health challenges the focus tends to be on
- treatment of immediate symptoms
- proximate causes, mechanisms
Why pain, fever, cancer, and negative emotions?
despite obvious costs, increase chances of surviving those challenges
What is health status from an evolutionary perspective
multidimensional. anatomical and physiological integrity and function can be modified as the result of lesions, genetic mutations, malfunction or in response to environmental challenges. Those changes may result in undesirable, painful, or uncomfortable outcomes
a holistic perspective should include
a full explanation, both proximate and ultimate explanations
should we analyze only ultimate or only proximate explanations
no, it would be a mistake
collection of epidemiological data
- analysis of vital stats on morbidity and mortality
- analysis of large scale population surveys and surveillance
who collects data
government, religious authorities, nurses, doctors, local health centers
two main quantifiable outcomes
- measures of morbidity
- measures of mortality
what are measures of morbidity
- incidence and prevalence
what is incidence
number of new cases during a particular time interval
What is prevalence
The total number of all (old and new) cases of a disease in a given population during a particular time interval
Why is the difference between prevalence and incidence largest when evaluating chronic conditions
chronic diseases have a long duration, increasing prevalence
What are four basic designs
- RCT
- Cohort
- case control
- cross sectional
what are cohort studies
follow same individuals through time (prospective and retrospective (naturalistic longitudinal studies))
what is infectious disease/communicable disease
caused by specific agents or their toxic products which are transmitted from one person to another, directly or indirectly
What is noninfectious disease
not transmitted from person to person
what is endemic
presence of a certain disease at a relatively constant level at all times
What is epidemic
when number of cases in a fairly localized area suddenly increases above the expected level for a short time
What is pandemic
when number of cases increases worldwide
What are key traits of infectious disease
virulence, transmissibility
What is transmissibility
rate at which an infection spreads, usually depends on density of hosts and the virulence of the parasite population
what is virulence
The relative effect of a pathogen on its host’s health…
- the ability of any agent of infection to produce disease, a measure of the severity of the disease a pathogen is capable of causing
What are different types of transmission
- directly transmitted diseases - transmission via direct contact between hosts
- indirectly transmitted diseases
What are types of directly transmitted diseases
- horizontal - any form of transmission that is not maternal and through direct contact between individuals
- vertical transmission - maternal transmission from mother to offspring
What are types of indirectly transmitted diseases
- vehicle born
- vector borne
examples of direct transmission
- respiratory, sexual, direct physical contact
examples of indirect transmission
- vehicle
- water born
- food born
- soil born
- needle sharing - vector
- mosquitoes
- ticks
- fleas
- lice
- flies
why are pathogens pathogens
because of their cost to the host
where does costs to the hosts result from?
parasites’ use of the hosts resources or damage it causes to the host in its attempt to survive, reproduce and spread
what do traditional health sciences tend to focus on
effects of virulence and proximate causes
What does an evolutionary and ecological perspective provide
critical information about the ultimate causes of the patterns of virulence and transmission. info can be used to properly prevent and treat outbreaks
- by focusing on life history of parasite and host simultaneously
what is virulence the product of
complex interactions among evolutionary, ecological, and epidemiological processes
examples of evolutionary and ecological changes affecting population dynamics of disease/affect virulence
- spatial structuring
- within host dynamics
- polymorphism in host resistance
- host longevity
- population size
natural selection leads to the optimization of
virulence strategies, which should vary according to the environment
if we can control the _______ we can control their ______ and _________
environment, transmission, virulence
do parasites not harm or kill host
FALSE
describe life history trade offs between persistence (host survival_ and fecundity
given that greater host exploitation is likely to increase transmission rate but also to reduce host survival and, hence, the time available for transmission.
Why does vertical transmission tend to reduce virulence
vertical transmission tends to depend on host survival and reproduction
what is cordyceps
influence nervous system to alter host behaviour
What is direct life cycle
only one definitive host
how does transmission increase in parasites with a direct life cycle
increased social contact with conspecifics
What is indirect life cycle
lifecycle includes more than 1 host species
What is a way pathogens spread when they have an indirect life cycle
predation….if pathogens hosted by prey may change behaviour so risk of predation increased
What is a way pathogens spread when its an STD
increased sexual behaviour/hidden symptoms so more sex
What do we need to develop preventative strategies and treatments
understand parasite’s life cycle and the strategies it uses to reach its hosts (genetic, physiological, behavioural)
