Week 1: Biology and Public Health Flashcards
What is public health?
Public health refers to all organized measures (whether public or private) to prevent disease, promote health, and prolong life among the population as a whole
What makes public health different from the other health professions?
Public health focuses on the health of entire populations while they are still healthy rather than on individual patients after they become sick
Name 7 different disciplines involved in public health.
Epidemiology
Biostatistics
Public health laboratory practice
Nutrition
International and global health
Public health policy
Health education
Environmental health
Maternal and child health
Public health practice
Emergency medical sciences
What are the 3 main public health functions?
Assessment and monitoring of the health of communities and populations at risk to identify health problems and practice
Formulation of public policies designed to solve identified local and national health problems and priorities
Assure that all populations have access to appropriate and cost-effective care, including health promotion and disease prevention services
What are 3 impacts of public health?
Increase in life expectancy
Worldwide reduction in infant and child mortality
Elimination or reduction of many communicable diseases
What is the breakdown of the roles public health and medical advances have played in increasing lifespans of populations?
Over 25 years of public health and less than 4 of medical advances
What are 6 reasons that demonstrate the need for biology in public health?
Basic knowledge in biology helps with understanding infectious disease transmission, vector and reservoir animal population dynamics
Helps to control zoonotic disease that require knowledge of infectious agents (life cycle and transmission) along with their prevention methods
Use of chemical and biological control agents
Helps to independently conduct scientific studies required to evaluate animal-related disease and control problems
Helps to distinguish among the characteristics of viral, bacterial, parasitic, and other types of disease pathogens
Helps to identify the known associations between genetic factors and common diseases
What is the graphic for the dynamics of disease called?
The epidemiological triad
What are the 3 corners of the epidemiological triad?
- Agent or microbe that causes the “what”
- Host or organism harboring the disease (“the who”)
- Environment or those external factors that cause or allow disease transmission (“the where”)
Give 1 detail about the agent or microbe that causes the “what.”
Disease-causing microbes are bacteria, virus, fungi, and protozoa (a type of parasite)
Give 3 details about the host or organism that harbors the disease (“the who”).
Can be organism that gets sick or any animal carrier (like insects or worms) that can/cannot get sick
Also includes symptoms of disease
Different people may have different reactions to the same agent
Give 2 details about the environment or external factors that cause or allow disease transmission (“the where”).
Favorable surroundings and conditions external to the host that cause or allow the disease to be transmitted
Other factors include the season and time
What 3 things can “time” refer to when talking about the epidemiological triad?
Incubation period: time between host infection and disease symptoms occur
Duration of the illness
Period from an infection to the threshold of an epidemic for a population
How many factors are necessary to interact after the outcome (deviation from normal homeostasis)?
At least 2
What are 3 examples of environmental diseases?
Toxins (lead poisoning)
Cancers
Environmental shortages (famine)
What system is used when talking about directly transmissible infectious disease?
Two population system
Give 3 examples of two population systems.
Many viral (influenza, measles), bacterial (tetanus), and fungal (aspergillus) infections
What are zoonotic diseases? Give 2 examples.
Zoonotic diseases: pathogen primarily resides in second species and is transmitted to humans without an intermediary species
Examples: rabies and schistosomiasis
Summarize the epidemiological triad.
The mission of the epidemiologist is to break one of the legs of the triangle, which disrupts the connection between environment, host, and agent, stopping the continuation of an outbreak
Goals of public health: control and prevention of disease
By breaking one of the legs of the triangle, public health intervention can partially realize these goals and stop epidemics
What are the 4 broad categories of the determinants of health?
Social factors
Health services
Individual behavior
Biology and genetics
List 7 major determinants of health.
Where you live (middle or low income countries)
Genetics
Income (USA)
Nutrition (middle or low income countries)
Education (USA)
Relationships with friends and family
Gender
Culture
Social status and social exclusion
Access to and use of health services (middle income or low income countries)
Personal health behaviors
Summarize the scientific method.
Make observations (ask questions, gather information)
Formulate hypotheses (propose explanation for observations)
Prediction (based on hypothesis, project outcome)
Experiment (test prediction, modify hypothesis)
Emphasis on steps sometimes differs in “modern” practice
What disease did John Snow help prevent?
Cholera
Summarize the story of John Snow and the first cholera outbreak.
Infectious diseases were leading cause of death in mid-19th century
Up to half of all children died before the age of 5, mostly due to infectious disease
Snow’s first study was conducted in 1848 when an epidemic of cholera hit the Golden Square area of London
Even before bacteria were discovered as a cause of disease, Snow was able to stop devastating outbreaks by observing and recording information about the distribution of the disease
Observation and hypothesis:
Cholera outbreaks (recently seen in Haiti) were previously common and a major cause of death
Mid-1800s: existing data on cholera deaths were consistent with a theory of a “miasmatic” cloud
Cloud was said to hover close to the ground
Hypothesized that water polluted water was the cause of cholera, and when one water company moved its intake upstream on the Thames in London, he had a basis for testing the hypothesis
Snow developed a spot map that showed the distribution of cases in relation to water pumps
After investigating, he found that many cholera cases were clustered around the Broad Street Pump and confirmed with families of cholera victims that they used the pump
Showed that by studying the case distribution, a source of infection could be found that explained the pattern
He stopped the epidemic by having the pump handle removed
Summarize the story of John Snow and the second cholera outbreak.
Snow did additional pioneering work during another cholera outbreak In 1854
Outbreak affected several areas of London that depended on water hauled in by wagon
Two companies did the hauling and Snow compared the number of cholera deaths in the various districts
Raw numbers could not tell him much because some districts couldn’t be compared due to different populations
He collected population figures from the most recent census and calculated cholera death rates per 1,000 people
Death rate was 22x higher in the districts served by only one company compared to districts served only by the other one
Further investigation showed that both companies were drawing their water from the Thames
Snow showed conclusively that water could serve as a vehicle for transmitting infection; also showed humans could intervene, in this case by changing the location of the company’s water intake
