What is Public Health?
The Fulfillment of society's interest in assuring the conditions in which people can be healthy OR Organized community efforts aimed at the prevention of disease and the promotion of health.
What are the core functions of Public Helath?
Assessment, Policy Development, and Assurance.
What is Assessment?
- 1. Monitor health status to identify community health problems.
- 2. Diagnose and investigate health problems and health hazards in the community
What is Policy Development?
- 1. Inform, educate, and empower people about health issues
- 2. Mobilize community partnerships to identify and solve health problems
- 3. Develop policies and plans to support individual and community health efforts
What is Assurance?
- 1. Enforce laws and regulations that protect health and ensure safety
- 2. Link people to all needed personal health services and assure the provision of health care when otherwise unavailable
- 3. Assure a competent public health and personal healthcare workforce
4. Evaluate effectiveness, accessibility, and quality of personal and
population-based health services
What is the difference between Public Health and Medical Care?
- In medicine its about the individual patient and in public health it is about the community.
- PH diagnoses the health of the community
- Treatment of the community involves new policies and regulations
- Medicines cures and public health prevents (theoretically)
What is the relationship in PH between Science and Politics?
Science is how we understand the threats and Politics is how we make decisions about what policies to implement.
What is Epidemiology?
Basic science of Public Health, study of epidemics, aims to control spread of infections, seeks cause of chronic disease and ways to limit harmful exposures.
What is the role of Statistics in PH?
- Collection of Data on the population
- Number are diagnostic tools for the health of a community
- Calculate risk and benefits
Examples of Biomedical Sciences?
- Infectious diseases - pathogens
- Chronic Diseases
Examples of Environmental Health Sciences?
- Health Effects of environmental exposures
- Air Quality
- Water Quality
- Solid and Hazardous Wastes
What are the three types of Prevention?
- Primary Prevention
- Secondary Prevention
- Tertiary Prevention
What is Primary Prevention?
- Prevents and illness or injury from occurring at all, by preventing exposure to risk factors.
- E.g. - Telling teens to not smoke
What is Secondary Prevention?
- Seeks to minimize the severity of the illness or the damage due to an injury-causing event once the event has occurred.
- E.g. - Programs are implemented to catch early when it is still treatable
What is Tertiary Prevention?
- Seeks to minimize disability by providing medical care and rehabilitation services.
- E.g. - Care and rehabilitation services for cancer patients
What is the Public Health Approach?
- Define the health problem
- Identify the risk factors associated with the problem
- Develop and test community-level interventions to control or prevent the cause of a problem
- Implement interventions to improve the health of the population
- Monitor interventions assess their effectiveness
What is intervention?
Interventions can be directed toward eliminating or suppressing the agent that causes an illness or injury, strengthening the resistance of the host to the agent, or changing the environment in such a way that the host is less likely to encounter the agent.
What is social justice?
- The common good
- Individual Responsibility
- Minimal levels of income, basic housing, employment, education, and health care should be seen as fundamental rights.
What are the sources of controversy in PH?
- Economic Impact
- Individual Liberty
- Moral and Religious Concerns
- Politics vs Science
What is Market Justice?
Emphasis on individual responsibility, minimal obligation to the common good, and the fundamental freedom to all individuals to all individuals to be left alone. Under market justice, powerful forces of environment, heredity, and social structure prevent a fair distribution of the burdens and benefits of society.
What is the Tragedy of the Commons?
There is one pasture open to all herdsman in the community. If each herdsman tries to put the maximum number of cattle in said pasture to benefit himself, the pasture will become over-grazed and no one will benefit. The solution is to put limitations for each herdsman on proper use of the pasture. Today, our "commons" are air, water, and other parts of the environment that people must share. To protect these resources the government sets limitations.
When is it appropriate for the government to restrict individual freedom?
- To prevent harm to others - generally acceptable
- Paternalism - Acceptable for Children
- To protect others from their own actions (opposed by libertarians)
- For the Common Good - Lots of controversy
What role does each branch of government play in public health?
- Legislative - Passes Statutes
- Executive - PH agencies carry out the laws; may issue regulations consistent with statutes
- Judicial - Laws and regulations can be challenged in court
What is the responsibility of local health agencies?
- Day-to-day responsibility
- County and City Health Depts
- Core public health functions
Collecting health statistics
- Providing screening and immunizations
- Providing health education services and chronic disease control programs
- Conducting sanitation
- Sanitary engineering
- Inspecting programs
What is the State Health Dept responsible for?
- Coordinate activities of local health agencies and provide funding
- Collect and Analyze Data
- Laboratory Services
- Manage Medicaid
- License and certify medical personnel, facilities and services
- Environment, mental health, social services, and aging may be handled by separate agencies
- Receive some finding from taxes
What is the responsibly of the Federal Agencies?
- They have the authority to establish and enforce laws and regulations on issues that need a national scope.
- Lead and assist state and local governments in providing public health services through funding from their ability to tax and spend.
What are some examples of Federal Agencies?
- National Institute of Health
- Center for Disease Control
- Department of Agriculture
- Department of Transportation
What is the Centers of Disease Control and Prevention?
- Main epidemiologic and assessment agency for the nation
- Publishes Morbidity and Mortality Weekly Report
- Centers for Health Statistics
- Centers on infectious diseases, chronic disease, injury prevention, and others
What is the National Institutes of Health?
- Biomedical research agency
- Institutes on Cancer, Heart and Lung Disease, DM, aging, child birth, and human development
- National Library of Medicine
What are some Nongovernmental PH organizations?
- American Cancer Society
- American Heart Association
- American Medical Association
What are Philanthropic Foundations?
- Bill and Melinda Gates Foundation
- Commonwealth Fund
- Rockefeller Foundation
What are police powers invoked?
- To prevent a person from harming others
- To defend the interests of incompetent persons such as children or the differently abled.
- To protect a person from harming himself or herself
What is Epidemiology?
- The Diagnostic discipline of PH
- A major part of PH assessment function
- Investigates causes of disease
- Identifies trends in disease occurrence
- Evaluates effectiveness of medical and public health interventions
- An observational science
What is an endemic? Endemic Level? Endemic Rate?
- Natural to or characteristic of a specific people or place; native; indigenous.
- •Endemic level: The usual prevalence of a disease within a given geographic area.
- •Endemic Rate: The frequency of a disease in comparison to the usual or expected rate.
What is Epidemic surveillance?
- Endemic vs Epidemic
- Notifiable diseases
- Recognition of new diseases
- Increased importance with threat of bioterrorism
What is an Epidemic?
The occurrence in a community or geographic area of disease at a rate that clearly exceeds the normally expected rate (endemic rate).
What is Epidemiology?
The study of the pattern of disease occurrence in human populations and the factors that influence these patterns. The study of the distribution and determinants of disease frequency in human populations.
What is a notifiable disease?
Infectious diseases whose spread can be prevented if the appropriate actions are taken. It is required that these diseases be reported as soon as diagnosed.
When did Cholera surface?
- Epidemics in London mid 1850s
- John Snow discovered suspected water supply, first epidemiologist
What are Risk Factors?
Characteristics that have been demonstrated statistically to increase a person’s chance of developing a disease or being injured.
What occurs during an Outbreak Investigation?
- Verify the Diagnosis
- Construct a working Case definition
- Find cases systematically - active surveillance
- Ask Who, Where, When questions. Consider the incubation time
- Look for a common source of exposure
What Disease Frequency?
- Count the number of people with disease and relate to the population at risk (PAR)
- PAR (denominator) may be total population or exposed population, or one gender or age group; often comes from census
What are the two ways to measure disease frequency?
- Incidence - Number of new cases, also used in studying causes of disease
- Prevalence - Number of existing cases
- If causes or risk factors increase, incidence and prevalence increase
- If ability to diagnose increases, incidence and prevalence increase
- Prevalence depends on incidence and prognosis
What is Distribution of Disease?
- Comprised of the answers to the who, when, and where questions.
- When, looks for trends in disease frequency over time
- Where, comparison of disease frequency in different countries, states, countries, or other geographical divisions.
- Who, population ect.
What is a disease?
The Health Outcome
What are the kinds of Epidemiological Studies?
- Goal to determine an association between an exposure and a disease or other health outcome
- May be prospective or retrospective
- Intervention Study
- Cohort Study
- Case-Control Study
What is an Intervention Study?
- Closest thing to an experiment
- Two groups - Experimental Group (gets intervention) and control group
- Observe over time and compare examples
- Two groups should be as similar as possible
What is the ideal like of Intervention Study and what is it?
- Randomized, double-blind, placebo control is the ideal
- Randomized means that each subject is assigned to the treatment group of the control group at random. Double bind means that both the patient and the doctor are blind as to whether the patient is receiving the drugs or a placebo.
What are some examples of important Intervention Studies?
- Beta carotene to prevent cancer
- Kingston-Newburgh study of fluoridation to prevent tooth decay
What is a Cohort Study?
- A study of a group of people, or cohort, followed over time to see how some disease or diseases develop.
- Used when an intervention study cannot be done
- E.g. - Nurses Health Study
What is a Case Control Study?
- An epidemiologic study that compares individuals affected by a disease with a comparable group of persons who do not have the disease to seek possible causes or associations.
- Interview them all and ask for their previous exposures
- Advantage - Cheaper
- Least accurate approach
What is an Odds Ratio?
A measure of effect size, describing the strength of association or non-independence between two binary data values
What is Exposure?
An act of subjecting or an instance of being subjected to an action or an influence
What is Relative Risk?
A comparison of two morbidity or mortality rates using a calculation of the ratio of one to the other.
What is Rate?
- The proportion of some disease or condition in a group per unit of time, with a numerator and denominator (stated or implied) indicating
- so many per so many per year or other unit of time.
What is a Population at Risk?
A group of people who share a characteristic that causes each member to be susceptible to a particular event, such as nonimmunized children who are exposed to poliovirus or immunosuppressed people who are exposed to herpesvirus
What is Placebo Effect?
When a supposedly ineffective pill or agent used in a control group to gauge the effect of an actual treatment in another group. Experimenters often must allow for a placebo effect, a response caused by suggestion.
What is informed concent?
A phrase often used in law to indicate that the consent a person gives meets certain minimum standards
What is Confounding Variables?
Another factor or explanation that may affect a result or conclusion
What is Recall Bias?
A type of systematic bias which occurs when the way a survey respondent answers a question is affected not just by the correct answer, but also by the respondent's memory
What is Institutional Review Board?
A committee that has been formally designated to approve, monitor, and review biomedical and behavioral research involving humans.
What is Selection Bias?
A statistical bias in which there is an error in choosing the individuals or groups to take part in a scientific study
What is Reporting Bias?
Refers to a tendency to under-report unexpected or undesirable experimental results, attributing the results to sampling or measurement error, while being more trusting of expected or desirable results, though these may be subject to the same sources of error
What is Random Variation?
The way a coin will successively turn up heads or trials if flipped in just the same way
What are the three major types of epidemiological studies? What are the strengths and weaknesses of each type?
- Intervention, Cohort, and Case-Control study.
- Intervention - Subjects may NOT follow prescribed behavior throughout study period
- Cohort - Sometime hard to isolate which of the many factors are responsible for health differences
- Case-Control - Control groups may not be truly comparable; also errors in reporting or recall
Why was the Tuskegee study significant
Subject received free medical care and burial insurance for participation. Some of the volunteers has syphilis and others did not. They did not tell people if they have syphilis and did not give treatment to all people with syphilis even with knowledge they had it. This is no longer acceptable because patients need informed consent.
What are three characteristics of an epidemiologic study that would tend to make its conclusions credible?
Strong association, Dose-response relationship, Known biological explanation, large study population, and consistent result from several studies.
What are possible sources of error?
- Random Variation
- Confounding Variables
- Bias (selection and reporting bias or recall bias)
What factors Lend Validity to Results?
- Strong Association
- Dose-response Relationship
- Known biological explanation
- Large study population
- Consistent results from several studies
How and when were infectious diseases thought conquered?
What are the infectious agents?
- Bacteria: Living, single celled organisms that can grow and reproduce outside the body if given the appropriate nutrients
- Viruses: A very small pathogen that is not capable of independent metabolism and can reproduce only inside living cells.
- Parasites: An organism that lives off another organism (called a host) but does not contribute to the welfare of the host.
What is the Chain of Infection?
- A term used to describe the pattern by which an infectious disease is transmitted from person to person, composed of several links.
- Pathogen, Reservoir, Method of transmission, Susceptible host.
- Interrupt Chain of Infection at any link
What are the means of Transmission?
- Aerosol: A suspension of liquid particles in the air; many infectious diseases of the respiratory system are transmitted by pathogen-containing aerosols released when an infected person coughs or sneezes.
- Fecal-oral Route: Fecal matter from an infected person reaches the mouth if an infected person
- Sexual Contact
- Touching contaminated objects and putting hands to mouth, nose, and eyes
What are some ways to interupt the chain of infection?
- Kill pathogen with antibiotics
- Eliminate Reservoir
- Prevent Transmission (Wash hands, Quarantine, Condom)
- Increase resistance of host by immunization
What is a Host?
An organism that harbors a parasite.
What is Immunization?
Stimulating immunity to an infectious disease by exposing an individual to a weakened or inactivated pathogen or portion of the pathogen.
What is a Pathogen?
Virus, bacterium, or parasite that causes the disease in humans.
What is a Reservoir?
The place where a pathogen lives and multiplies
What are Smallpox, Measles and Polio?
Viral disease against which effective vaccines have been developed and which have no human reservoir.
What is Rabies?
A fatal disease of the nervous system caused by a virus, kills an estimated 55,000 a year, usually contracted by a dog bite.
What is Antibiotic Resistance?
Bacteria become resistant to an antibiotic. In the presence of an antibiotic drug, any mutation that allows a single bacterium to survive confers on a tremendous selective advantage.
What is AZT?
The first antiviral therapy approved by the FDA in 1987. This drug interfered with the replication of HIV by inhibiting the enzyme that copies the viral RNA into the cell's DNA. The virus's tendency to mutate rapidly leads to the development of resistance to the drug.
What is E coli 0157:H7?
Resistant to antimicrobials.
What is Bioterrorism?
Involving the intentional release or dissemination of biological agent
What is Influenza?
An RNA virus, constantly changing its appearance and adept at eluding recognition by the human immune system.
What is Influenza?
An RNA virus, constantly changing its appearance and adept at eluding recognition by the human immune system.
What are Emerging Infections?
An infectious disease whose incidence has increased in the past 20 years and threatens to increase in the near future.
What is Multidrug-resistant Tuberculosis?
A strain of TB that is resistant to most common anti-TB drugs, there are still some drugs that are effective against them although they are more expensive and are difficult to administer.
What are Prions?
- Contain protein but no nucleic acid and this no traditional genetic material.
- Egs - CJD, Madcow (BSE
What is Retrovirus?
A virus that uses RNA as its genetic material instead of the more usual DNA.
What are T4 Cells?
Component of immune machinery that is activated when the body recognizes a foreign invader such as a bacterium or a virus. The T4's role is to divide and reproduce itself in response to such an invasion and to attach the invader.
What is Eradication?
- Possible if no non-human reservoir and a vaccine exist
- Sm pox eradicated in 1977
- Polio eradicated from Western Hemisphere
- Measles is the new target
What are some of the fears associated with vaccines?
- Rumors of vaccines causing autism
- Side effects do exists for some vaccines
- Some parents refuse to accept risks
What is herd immunity?
Lost if people don't get vaccinated
What are pharmaceutical companies reluctant to develop vaccines?
- Low profit
- Risk of Lawsuits
What are some examples of emerging viruses?
- Monkey Pox
- West Nile Virus
What are some factors that Lead to Emergence of the new Infections?
- Human activities that cause ecological damage and close contact with wildlife
- Modern Agricultural Practices
- International Travel
- International Distribution of Food and Exotic animals
- Breakdown of social restraints on sexual behavior and intravenous drug use
What is Influenza?
- Virus is constantly mutating
- Vaccine must be changed frequently
- New, lethal strains appear periodically
What are some new bacterial threats?
- Legionnaire's Disease
- Lyme Disease
- Streptacoccus A
- E. coli 0157:H7
- Antibiotic Resistance (Improper medical use and in Ag)
What is TB?
- Leading cause of infectious-disease death worldwide; one third of population is infected
- Transmitted by aerosol
- Antibiotics are effective, but must be taken for several months
What is Education?
Informs public of healthy and unhealthy behavior.
What is Prohibition?
- 18th Amendment
- The legal act of prohibiting the manufacture, transportation and sale of alcohol and alcoholic beverages.
What is Regulation?
- Effective approach to promoting behavioral change, although it is often unpopular
- Laws against murder and assault
- Traffic Regulations
- Restrictions on alcohol, drugs, and tobacco
- Age restrictions on many behaviors
What is Recommended Daily Allowance (RDA)?
Average requirements for various age groups regarding vitamins and minerals.
What is the most important predictor of health?
What is socioeconomic status?
An economic and sociological combined total measure of a person's work experience and of an individual's or family’s economic and social position in relation to others, based on income, education, and occupation.
Why the effect of SES?
- Conditions of the physical environment
- Higher SES leads to more healthy behavior
- Access to medical care
What is Social Support?
- Perception and actuality that one is cared for, has assistance available from other people, and that one is part of a supportive social network.
- Social Support can buffer stress
What is Stress?
- Describes a negative concept that can have an impact on one’s mental and physical well-being, but it is unclear what exactly defines stress and whether or not stress is a cause, an effect, or the process connecting the two.
- Eg - Mortality is increased after death of a spouse, loss of a job, divorce
What is the health belief model?
- Several factors that determine whether a person is likely to change behavior when faced with a health threat
- 1. The extent to which the individual feels vulnerable
- 2. Perceived severity of the threat
- 3. Perceived barriers to taking action to reduce the risk
- 4. Perceived effectiveness of taking an action to prevent or minimize the problem
What is the Locus control theory (self-efficacy)
- An individual's perception about the underlying main causes of events in his/her life
- Increased by previous successful performance
- Increased by seeing others successfully preform, esp if model is a peer
What is self-efficacy?
People's beliefs about their capabilities to produce effects
What is the ecological Model of Health Behavior?
- Intrapersonal level (psychology)
- Interpersonal level (Family, friends coworkers)
- Institutional level ( School, workplace)
- Community Level (Churches, community organizations)
- Public Policy Level (government regulations)
What is the Animal Model?
Animals that stand in for human patients throughout testing and are susceptible to the disease one wishes to study.
What is Atherosclerosis?
Hardening of the arteries may lead to CHD.
What is Cancer?
Arises when the activities of a cell are transformed and the cell begins to grow out of control.
What is a Carcinogen?
Cancer causing chemicals
What is Cardiovascular Disease?
Disease of the heart and blood vessels, most commonly caused by atherosclerosis, deposits of fatty substances in the inner layer of the arteries. Coronary heart disease affects the arteries of the heart and may lead to a heart attack. Cerebrovascular disease affects the arteries of the brain and may lead to a stroke.
High Density Lipoprotein (HDL)?
Low Density Lipoprotein (LDL)?
Bad Cholesterol, leads to plaque buildup.
National Cancer Institute?
- Leads a national effort to reduce the
- burden of cancer morbidity and mortality by stimulating and supporting
- scientific discoveries through basic and clinical biomedical research
- and training.
A permanent transmissible change in genetic material
National Lung and Blood Institute?
Provides leadership for a national program in diseases of the heart, blood vessels, lung, and blood; blood resources; and sleep disorders.
Type ll Diabetes?
Complex mix of impaired insulin production and resistance to the hormone’s action. Closely associated with obesity.
Type l Diabetes?
Failure of the insulin-producing cells of the pancreas, usual childhood onset.
What is a Teratogen? Environmental examples?
- A substance that causes birth defects
- E.g. - Infectious Pathogens, Environmental Chemicals, Drugs, Alcohol
Autosomal Dominant Gene?
Disease can be transmitted through a single copy and the affected person will transmit that disease to on average half of his or her children,
Autosomal Recessive Gene?
Two copies of the affected gene must be present for disorder to present.
Human Genome Project?
A project which aims to analyze the whole of human DNA and make a map of all human genes.
Carriers are associated with recessive traits. A carrier may not present with any signs or symptoms but is capable of passing the genetic mutation.
What is carrier screening?
Screen for recessive genes in high-risk populations Tay-Sachs disease in Jews Sickle cell in AA
What is Newborn Screening?
- Prenatal diagnosis or the process of using a dried blood spot specimen to identify over 20 metabolic disorders.
- All newborns in US screened for PKU and hypothyroidism
- CF hard to test for
What is prenatal diagnosis?
Only remedy may be abortion in come cases
A condition in which the amino acid phenylalanine cannot be metabolized in the body.
Sickle Cell Disease?
Deformed RBC. Shorter life expectancy.
Defective gene on the female sex chromosome, called the X chromosome. These diseases occur in predominantly in males.
Village in southern Japan made famous by the poisoning of its population in the 1950’s by mercury released into the bay by a plastics factory. Most severely affected were children born with severe brain damage to mothers who had been exposed while pregnant
What are the Institute of Medicine's recommendations Concerning Genetic Testing?
- •Newborn screening should be done only when there is a clear indication of benefit to the newborn, when a system is in place to confirm the diagnosis, and when treatment and follow-up are available for affected infants
- •Carrier identification programs should be voluntary and confidential, and they should include counseling about all choices available to the identified carriers
- •Prenatal diagnosis should include education and counseling before and after the test, informing the parents about risks and benefits of the testing procedure and the alternatives available to them
- •All tests should be of high quality, because life and death decisions are based on the results. New tests should be evaluated by the FDA and there should be more government oversight of laboratory proficiency
- •There should be more education for the general public about genetics