PH200 F10
Terms
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- What is "health"? How do we measure health?
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WHO: "a state of complete well-being, physical, social, and mental, and not merely the absence of disease or infirmity"
no quantifiable measurement.
Measure health by:
-infant mortality rate
-life expectancy
-now moved to DALY: disability adjusted life years. 1 for 1 health year. 0.5 for really disabled. - How do the United States compare for infant mortality rate and life expectancy?
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Infant Mortality Rate: 28th
Life Expectancy: 23rd
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What are the leading causes of death by age?
What are the "real causes" of death? (i.e people die of heart disease, but what behaviors and factors cause this)
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1-44: unintentional accidents
44-64: cancers
>65: heart disease
Real causes:
-tobacco
-physical inactivity
-alcohol -
Cholesterol:
-gender differences?
-differences between now and in the 60s? Public health implications? -
Gender Differences:
-men > women
-Decrease due to drugs.
-Public Health implications: individually - not much difference between 200 to 160, but for public health this has huge benefits. - Factors associated with growth in health care expenditures, US
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1. General inflation
2. medical care-specific - prices going up
3. Population growth
4. intensity care - more services/more expensive services. - Definition of Public Health and Distinguishing Features
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Public health is the set of activities a society undertakes to monitor and improve the health of its collective membership.
Features:
1. Focus on PREVENTING disease & injury
2. "Patient" is entire community, not individual
3. "Provider" is society, not individual professionals. - Example of Medicine vs. Public health
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Medicine: dentist treats patient - one person, dentist = provider
Public Health: Fluoridated water - available to all members of the community, treats oral health because prevents cavities, society = provider -
Benefits and Costs of HEALTH Promotion Programs
Benefits and Costs of DISEASE promotion programs -
HEALTH Promotions: (e.g. exercise)
-benefits are abstract, future
(If I do this it will help avoid a heart attack, but not sure it will)
-costs are tangible, immediate
(hard, takes up time, sore)
DISEASE promotion programs
(the opposite of health promotion programs) - e.g. eating cake
-benefits immediate, tangible
-costs are abstract, deferred - 3 Core functions of public health
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1. Assessment of the health of the population
2. Development of public health policies
3. Assurance of the availability of needed services - 10 Essential Public Health Services
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1. Monitor health status to identify community health problems
2. Diagnose and investigate health problems and health hazards in the community
3. Inform, educate, and empower people about health issues
4. Mobilize community partnerships to identify and solve health problems
5. Develop policies and plans that support individual and community health efforts
6. Enforce laws and regulations that protect health and ensure safety
7. Link people with needed personal health services and assure the provision of health care when otherwise unavailable
8. Ensure a competent public health and health care workforce
9. Evaluate effectiveness, ability, quality of personal and population-based health services
10. Research for new insights and innovative solutions to health problems - 5 Core areas of public health
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1. epidemiology
2. biostats
3. environmental health
4. health behavior and health education
5. health management & policy - Explain the 5 core areas of public health
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1. Epidemiology: concerned with analyzing and describing patterns of occurrence and determinants of disease in human populations.
2. Biostats: the development and applications of stats and math methods to the design the analysis of public health problems and biomedical research.
3. Environmental Health Sciences: aims to protect human health from adverse environmental conditions - in particular from harmful practices and harmful exposures in air, water, and food in the workplace, home and ambient environment
4. Health Behavior and Health Education: addresses the factors associated with health related behavior and health status and develops and evaluates educational activities designed to improve individual and community health and quality of life.
5. health management and policy: focuses on improving access to and financing to and delivery of quality health services and developing and implementing cost effective health policies - Definition of Disease Prevention
- Definition: anticipatory action taken to reduce the possibility of the occurrence of a disease or to minimize the damage if the event does occur
- Levels of Prevention
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1. Primary:
-Disease status = susceptible
-Effects = preventions, reduces incidence
(e.g. - building divided highways, dietary exercise)
2. Secondary:
-Disease status = asymptomatic
-reduces prevalence/consequence
-e.g. requiring safer cars and practices, BP screening)
4. Tertiary
-Disease status = symptomatic
-reduces complications
(e.g. - EMS system, treatment for HBP) - Why are public health issues often contentious?
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1. Restrictions on individual liberties
-"tragedy of the commons": restrictions on you for the benefit of the public good
-paternalism: protects YOU
2. Blame the victim
3. Economic Interests
-economic powerhouses = powerful lobby
-benefits the poor, but wealthy end up paying for it
- current costs for future benefits
4. Morality Issues
5. Politics in science
-promote social agenda only if not getting reelected - Public Health Historic Practices
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1. defecation downstream
2. water ways/drainage systems
3. affluence associated with wealth (obesity, lead poisoning/radon)
**EARLY CODES OF PUBLIC HEALTH PRACTICES***
1. Personal cleanliness
2. Sanitation
3. Quarantine/isolation - Stages of the History of Public Health
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1. Ancient societies
-Code of Hammurabi: sanitation, disinfection, isolation, hygiene
2. Classic cultures (500 BC to 500 AD): physical activities/games, water systems/sewers, hospital
3. Middle Ages: spirituality - disease = punishment for sin
-plague
-leprosy (quarantine)
4. Renaissance and exploration:
-growth in population, cities
-emerging belief that the diseases were environmental, not spiritual
-period interested in science (identified whooping cough, malaria, etc)
-European diseases killed native americans
*Mass Colony: requires birth/death registry, prevent pollution
5. 18th century
-Industrial Revolution
-bad working conditions
-vaccination (smallpox)
-infectious disease still the major cause of death
-local boards of health
-Marine Hospital Service
6. 19th century PH
-first half: little progress (industrial revolution)
-2nd half: increase in biological knowledge, PH system
-John Snow (broad street pump, cholera)
-understanding of communicable diseases
-Shattuck: bible of PH. marks modern era of PH
-1st state health departments
-a lot of legislation
7. 20th century:
-ID still leading causes in early 20th century, vitamin deficiencies
-increasing health departments
-Marine Hospital Service --> public health service
EARLY 20th: PERIOD OF REFORM
-child labor, working conditions, FDA
-1st school of PH
-Great Depression: effects of unemployment, public works
-Social Security
HEALTH RESOURCES DEVELOPMENT PERIOD (1900-1960)
-vaccine: polio
-CDC
-Hill Burton Act - make hospitals part of national policy (failed)
-Medicare/Medicaid (LBJ) - success for coverage, bad for cost control
NOW: emphasis on health behaviors - Lessons Learned from Public Health
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1. Social, political, economic and institutional factors contribute to public health problems and their solutions.
2.Earliest human tribes learned health oriented practices, like elements of sanitation from trial and error.
3. Early generations of humans were smart and resourceful - with primitive technology
4. Formal health codes date back centuries although principally for "upper crust" of society (health practices skewed towards those with social status. occasionally disease associated with privilege)
5. PH often 2 steps forward, 1 back (e.g. middle ages, revolution)
6. Health always an admired characteristic, a "virtue"; illness reviled, seen as a form of punishment for sin
7. Most basic elements of PH practiced for centuries:
-Personal hygiene
-sanitation
-quarantine
8. Disease always greater to humanity than other forms of disease
9. PH has effectively dealth with disease before understanding bio (e.g. quarantine, BS pump)
10. science contributed a lot to PH
11. Complicated relationship between economic progress and health
-economic progress - new risk to health
12. Organization of formal PH agencies lacks logical coherence.
13. Greatest increases in PH in history - past century
14. History - exhibits an interest in the welfare of the community as a whole, rather than individuals.
15. PH: battle for social justice. - 3 perspectives for rationale of government involvement
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1. Law
2. Political Science
3. Economics - Conceptual hierarchy of government authority in PH in law vs reality.
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1. state gov
2. fed gov
(no legal provision for local gov)
reality: (b/c of money)
1. fed
2. state
3. local -
Law
Political Science Rationale for gov involvement
econ -
Law: clauses
PS: objective of political body to realize the interest of the community not satisfied by the invid.
prob: sometimes the good of the community and individual is different (e.g. pollution)
econ: correct for market failures
market failures: inequity, tech market failures - Mechanisms for implementing PH policies
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1. law/ordinace by legislative body
2. regulation/rules by admin agencies (FDA)
3. court mandate - challenges to law or regularion
- Roles of non governmental roles in PH
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1. education
2. lobbying
3. research
4. support - Descriptive vs. inferential stats
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Descriptive: describes the data
Inferential: recognizes the randomness (variability) of the data, makes inferences and predictions based on these data, help quantify stat strengths and weaknesses of the analyses - Bias and Variability
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Bias: systematic error in the design or conduct of a study that leads to a false association between exposure and disease
Selection bias: a particular problem in choosing subjects for (e.g. sending out a survey about dissatisfied relationships, and only a small percentage respond -- maybe those women are preferentially interested in the study). Major problem for case control studies.
Reporting/Recall Bias: when a study group and a control group systematically report differently even if the exposure was the same. (e.g. dietary intake, alcohol consumption,fictitious cleaner -- think "oh yeah, I could have been exposed to that")
- Name the 4 trial types
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1. Randomized Control: patients randomized into different intervention; only differ by treatment. Eliminates conscious bias of patient selection; averages out unconscious bias due to unknown factors
2. Case-Control Study: epidemiological study in which persons who have the disease are questioned about PAST exposures and compared with exposures of persons who do NOT have the disease
(maybe not likely to remember details of their past -- recall bias)
3. Cohort Study: epidemiological study in which large numbers of people are questioned about their exposures and FOLLOWED over time to look for disease and factors that might be related to developing the disease
(problem: confounding variable)
4. Cross Sectional Study: observation of people at a specific time. aim to provide data about an entire population -
Strength of Statistical Evidence:
-p values and confidence intervals -
p value: probability that the results you got were due to chance. want small p-value to show that the results you found were not just due to chance.
Confidence interval: repeat this study 100 times, 95x the true parameter will fall in that interval
-If increase confidence, then increase size of confidence interval (more likely that your value will be in that interval)
-If increase sample size, then keep same confidence but narrower intervals - 4 definitions for diagnosing and detection errors
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Sensitivity: probability a test will result will be positive when the disease is present
Specificity: probability test result will be negative when disease is NOT present
Positive predictive value: probability the disease is present when the test result is positive
Negative predictive value: probability the disease is NOT present when the test result is negative - Criterion value
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More stringent criterion value: increased specificity, decreased sensitivity (Decreasing false negatives)
*Best: want high sensitivity and specificity
[graph: specificity = y axis; 100-sensitivity = x axis) -
Endemic
Epidemic
Pandemic -
Endemic: the usual occurence of a disease within a given geographical area
Epidemic: the occurrence of an infectious disease clearly in excess of normal and generated from a common propagated source
Pandemic: a world wide epidemic affecting an exceptionally high proportion of the global population - 10 steps of an outbreak investigation
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1. Prepare fieldwork
2. establish the existence of an outbreak
3. verify the diagnosis
4. define and identify cases
5. Describe and orient the data in terms of person, place, and time
6. Develop hypotheses
7. Evaluate hypotheses
8. Refine hypotheses and carry out additional studies
9. Implement control and prevention measures
10. Communicate findings - Case definition includes 4 components
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1. clinical information about the disease
2. characteristics about the people who are affected (person)
3. Information about the location (place)
4. Specification of time during which the outbreak occurred (time) - Descriptive epidemiology
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Step 5 in identifying an outbreak.
characterizing an outbreak by time, place, and person.
shows what is/is not reliable. provides comprehensive description of an outbreak by showing trend over time, its geographic extent, and populations affected by the disease - Hypotheses should address 3 things
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1. SOURCE of agent.
2. MODE OF TRANSMISSION (vehicle, vector)
3. EXPOSURES associated with the disease.
should be proposed in a way that can be tested. - Elements of Epidemic Control (3)
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1. Controlling the source of the pathogen
2. Interrupting mode of transmission
3. Controlling or modifying the host response to exposure - Prevalence vs. incidence
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Prevalence: total number of cases of a disease existing in a defined population at a specific time.
incidence: rate of NEW cases of a disease in a defined population over a defined period of time (e.g. how many developed flu THIS MONTH) - 3 situations that favor the use of RCT
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1. exposure of interest is a modifiable factor over which individuals are willing to relinquish control
2. legitimize uncertainty regarding the interventions on outcome, but reasons to believe the benefits outweigh the risks (e.g. all drugs must go through clinical trials)
3. Effect of intervention on rare outcome is of sufficient importance to justify a large study -
Typical comparisons in RCTs
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1. placebo
-not justified if intervention of known effectiveness is already in use
2. alternative intervention
3. "usual care"
- How do we know RCT worked?
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Know it worked:
look at incidence of people:
1. exposed to factor -- good and poor outcome
2. not exposed -- good and poor outcomes
Compare: #developed disease/total people with drug a with placebo developed disease/total people with placebo - Strengths and Weaknesses of Cohort Studies
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1. temporal sequence -- look ahead
2. assess multiple outcomes from a single exposure
3. study new or unusual exposures
4. calculates measures of risks and rates of disease in unexposed individuals
Weaknesses:
1. expensive
2. inefficient for studying rare disease
3. long duration for outcomes (subjects)
4. People can change classification - 2x2 Table for a case control study
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(exposure and has disease)*(no exposure and no disease)
____________________
(exposure and no disease)*(no exposure and has disease) - PKU
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Phenyleketonuria: new born
need special diet with no Phenylalanie - prevents retardation
Started first newborn screening: Guthrie Card Bacterial Inhibition Assay: time-tested, inexpensive, simple, and reliable test.
Mode of transmission: autosomal recessive gene; inborn error of metabolism. - Why study infectious diseases?
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1. Common
2. Cause substantial morbidity and mortality
-still many people dying from them today even compared to heart disease
-an issue worldwide, children
3. Constantly emerging and re-emerging
-increasing rates for chlamydia (men>women... due to screening?)
-gonorrhea (decreased, but much greater in blacks)
4. preventable
-ex: cervical and anal cancers, yet there are many cases world wide
5. incredibly interesting
- One pathogen, one disease: explain the 4 traits to this theory
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1. microbe should be found in all with disease but not in healthy animals.
2. microbe must be isolated from diseased organisms and grown in pure culture
3. Cultured organism could cause disease when introduced to a healthy animal
4. Microorganism must be re-isolated from disease, inoculated animal and identified to that isolated from the first animal - 4 traits of infectious diseases
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1. Can be transmitted between individuals
2. infection DOES NOT necessarily mean illness
3. One person puts the entire population at risk (but transmission mode and contact patterns matter)
4. If provoke an immune response may vaccine preventable - Transmission modes
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1. food or water borne
2. Vector borne
3. airborne
4. person to person direct contact
*THESE ARE NOT MUTUALLY EXCLUSIVE
Can have a big impact on stopping infectious diseases if know the mode of transmission (ex: pigs/raw pork -- triconosis, clean water -- polio; mosquito;
Life cycle of a guinea worm -
HIV and Race/Ethnicity
HIV and Education
Age differences among MSM -
Greatest percentage of HIV/AIDS in blacks even though they make up less of the population (1 white: 7 blacks)
White MSM > black MSM> black heterosexual women>hispanic MSM>black heterosexual men
Probability goes down, more likely to be enrolled in college (blacks, less of a decrease...)
Age: white -- 30-39, blacks/hispanics -- 13-29 -
HIV Prevention Programs
Sex Ed -
Sex ed:
1. Comprehensive Sex Ed
2. Abstinence-Plus
3. Abstinence only
*most people prefer abstinence plus. Not necessarily religious or political groups that are pushing abstience only. - Ecological perspectives on Health Promotion
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**Examine the joint/cumulative effects of personal/environmental factors in designing health promotion programs
**take into account linkages between various settings and levels. how change at one affects others
INDIVIDUAL:
-knowledge
-perceived threat
-sex practices
-substance use
-STI comorbidity
-condom self efficacy
INTERPERSONAL/Relational Structures
-peer norms, sex behaviors
-partner characteristics and relationship power
-paternal support
-neighborhood characteristics
-school characteristics
INSTITUTIONAL:
-lack of access to health care
-HIV/STI stigma
-sex norms and scripts
-cultural norms
-religious/spiritual norms
-social isolation and discrimination
META Structure
-poverty and unemployment
-lack of educational opps
-access to care
-illegal citizenship
-substandard housing
-social isolation and discrimination
- HIV Prevention: steps
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1. Understand HIV outcome
2. Situate and understand the health behavior you want to change. (different levels)
3. What theories may inform the development of strategies
--WHY people are engaging in the health behavior
--WHAT needs to be evaluated to demonstrate policy effectiveness
--HOW to shape program strategies to reach people
4/5. Develop and Test the intervention - Future Directions for Smoking Prevention Programs
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1. more of the same
-increase taxes (more burden on the poor
-more places smoke free (what happens once all places are smoke free?)
-more media campaigns ($$, burn out)
-greater access to cessation assistance
2. New policy (likely)
-more smoke free places
-product regulation (max nicotine; restrictions of marketing)
3. New Policy (LESS likely)
-confiscatory taxation?
-More restrictive smoke free laws
-serious, unusual product regulation - Generalizable lessons from smoking regulation
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1. most powerful drivers of health behavior come from social norms. (smoke free laws, antismoking ads)
2. Process of social (and norm) change illustrated by tobacco control story inovlves
-info/ed first
-elites - (most politically enfranchised) - lobby for policy changes
-middle/lower SES respond to social pressures and environmental changes
3. Use multiple intervention types
4. Form short-term perspective, creating culture and behavioral change is frustrating when individuals often seem unresponsive
5. long overhaul - worth it - Evolution of humans and diet
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Early humans = struggled to find food/adequate food sources
genetic craving for fats/sweets: necessary for survival
Today: minimal effort to get food - Diseases associated with poor diet and lack of physical inactivity
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Diabetes
heart disease
cancer
kidney disease
dementia
depression
preg complications
arthritis -
Controversy of obesity
Complexities -
"protective effect" for overweight and obesity for >55 when control for other variables
-increased mortality risk for morbidly obeses
-physical activity related to mortality risk
-underweight: higher death rate?
Complexities:
-fit vs. fat: fit more important
-cause and effect of underweight
-overweight (not obesity) in elderly -- sign of being well nutritioned -
How is obese defined?
Gender differences? Ethnicity differences? -
BMI:
overweight: 25-29.9
obesese - 30-34.9
morbidly obese - >35
limitations: fit vs. fat
Women: more obese than men now, but both increases.
Big disparity between blacks>hispanics>whites (cultural?)
big disparity for native americans in obesity in kids -
Most obese states vs. least
what underlies the obesity epidemic? -
Most: mississipi, alabama, west va
least: CO, MAss, conn
-genetic cravings vs. need
-calories in>calories out
-decreased physical activity (commute, sedentary leisure time, desk jobs)
-economics: (price food decreased - greater portions, manufactured calorie dense foods; cheaper; lack of grocery stores, 2 worker families - more restaurant takeout)
-changes in portion sizes
-schools (availability of nutirion, decrease phys ed and health ed, fewer safe routes to walk to school)
-workplaces: lack of time phys inactivity, sed jobs, unhealthy food optons
-environment - commuting, few parks
-industry behavior - marketing for sugary cereals for kids, PR (push for INDIVIDUAL responsibility), product placement in movies, political influence, "revolving door", Promote self indsuty, work with legislators to develop weak legistation -
Physical activity matters...
amount and nature of activity -
-biggest gain: least to moderately active
-guidelines for adults: 2.5hrs/week of moderate, 1.25 vigourous, muscle 2days
-guidelines for children: min 60min/day - moderate to vigorous >3x/wk, muscle strength 3x/week
Trends in adults:
-a lot not physically activity
-50% not meeting minimum
-phys active decrease with age
-women less engaged in moderate or vig phys activity
-AA and Hispanics less phys active than whites
Trends in Children:
-9 - 3hrs/day moderate to vig activity
age 14: less than an hour a day/wek day ~30 min for weekend - 2 reasons for decrease in infant mortality rates since 1950
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-immunization
-treatment for diarrheal diseases
(electrolyte therapy)
- Major Causes of Maternal Mortality in developing countries
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1. ruptured (etopic preg)
2. complications of abortion
3. obstructed labor
4. pre/eclamisa
5. post partum hemmorage (bleeding)
6. infection - FC/FGM: definition and reasons why
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"all procedures involving partial or total removal of the external female genitalia or other injury to the female genital organs whether for cultural or non-therapetuic reasons"
why:
-rite of passage
-presever chastity
-ensure marraige
-hygine
-improve fertility
-religion
-enhance sex pleasure for men
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3 types of FC/FGM
and complications -
1. Excision of prepuce, partial clitoridectomy, total clitoridectomy
2. Clitoridectomy, partial or total excision of labia minora
3. Clitoridectomy; excision of: labia minora and labia majora; infibulation: reapproximation of remnant labia majora; creation of neointroitus
immediate Complications:
-hemorrhage
-acute infections
-hypotension
-urinary retention
-shock
-death
long term complications
-keloid formation
-dyspareunia
-dysmenorrhea
-urinary issues
-HIV/Aids
-psychosocial issues