COMMUNITY HEALTH
3.2.1 Environmental Health – description
•According to WHO, Environmental health addresses all the physical, chemical, and
biological factors external to a person, and all the related factors impacting behaviours.
•It encompasses the assessment and control of those environmental factors that can
potentially affect health.
•It is targeted towards preventing or controlling diseases related to the interactions btn
people and the environment and also creating health-supportive environments.
•This definition excludes behaviours not related to environment, as well as behaviours
related to the social and cultural environment, and genetics.
•From this definition, Environmental health can be said to be a branch of public health
concerned with all aspects of the natural and built environment affecting Health.
•As a fundamental component of a comprehensive public health system, Environmental
health works to advance policies and programs to reduce diseases and other
environmental exposures in air, water, soil and food to protect residents and provide
communities with healthier environments.”
3.2.2 Facets of Environmental Health
1. Environmental epidemiology − Associations between exposure to environmental agents
and subsequent development of disease
2. Environmental toxicology − multidisciplinary field of science concerned with the study
of harmful effects of various chemicals, biological and physical agents on living agents
3. Environmental engineering − Factors that govern and reduce exposure
4. Preventive medicine − Factors that govern and reduce disease development
5. Law − Development of appropriate legislation to protect public health
3.2.3 Key Services in Environmental Health
1. Water safety & quality control
2. Food safety & quality control
3. Waste management (solid & Liquid)
4. Vector control
5. Pollution control
6. Occupational health and safety
7. Environmental impact assessments
8. Port health
9. Accident prevention
10. Environmental health measures associated with epidemics, emergencies, disasters and
migrations of populations
11. Air quality management
12. Environmental radiation hazards
13. Accommodation establishments
14. Establishment of an effective environmental health surveillance and information system
15. Research on environmental health issues
3.2.4 Why Is Environmental Health Important?
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•Maintaining a healthy environment is central to increasing quality of life and years of
healthy life.
•Globally, 23% of all deaths and 26% of deaths among children under age 5 are due to
preventable environmental factors (WHO, 2020).
3.2.5 Environmental Health factors
•Environmental Health factors are diverse and far reaching.
•They include:
•Exposure to hazardous substances in the air, water, soil, and food
•Natural and technological disasters
•Climate change
•Occupational hazards
•The built environment
•The natural environment
CHAPTER 4: CONCEPT AND SCOPE OF COMMUNITY HEALTH
4.1 Description of Community Health
▪Community health refers to the health status of a defined group of people and the
actions and conditions to promote, protect, and preserve their health.
▪(e.g. the health status of the students of Chuka University and the private and public
actions taken to promote, protect, and preserve the health of these people would
constitute community health)
• A perspective on public health that assumes community to be an essential determinant of
health and the indispensable ingredient for effective public health practice.
▪Community Health is part of the larger public health effort that is concerned with
preserving and promoting the health of specific populations and communities.
▪It takes into account the tangible and intangible characteristics of the community – its
formal and informal networks and support systems, its norms and cultural x-tics, and its
institutions, politics, and belief systems.
4.2 Basic Elements of Community Health
a) Promotion of health
• This includes all efforts that seek to move people closer to optimal well-being or higher
level of wellness. It is the combination of educational and environmental supports for
action and condition of living conducive to health.
b) Treatment of disorders
•This focuses on the illness end of continuum and is the remedial aspects of
community health practice.
•This is practiced by:
•Direct service to people with health problems; (e.g. home visit for elderly peoples,
chronic illness, etc
•Indirect service; e.g. assisting people with health problem to obtain treatment and
referral.
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•Development of program to correct unhealthy condition; e.g. alcoholism, drug
abuse, etc.
c) Rehabilitation
• This involves efforts which seek to reduce disabilities, as much as possible, and restore
functions; e.g. stroke rehabilitation.
d) Evaluation
• This is the process by which the practice is analyzed, judged, and improved according to
established goals and standards. It helps to solve problems and provides direction for
future health care planning.
e) Research
• This is a systematic investigation which helps to discover facts affecting community health
and community health practices, solve problems, and explore improved methods of health
services.
4.3 Essential Services of Community Health
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 the community partnerships to identify and solve health problems
5. Develop policies and plans that support individual and community efforts
6. Enforce laws and regulations that protect health and ensure safety
7. Link people to needed personal health services and assure the provision of health care
when otherwise unavailable
8. Assure a competent public health and personal health workforce
9. Evaluate effectiveness, accessibility, and quality of personal and population-based health
services
10. Research for new insights and innovative solutions to health problems
CHAPTER 5: HISTORICAL DEVELOPMENT OF PUBLIC HEALTH
5.1 Key Milestones in the History of Public Health
A. Early Civilizations 1) Ancient Societies (prior to 500 B.C.)
•Prior to 2000 B.C.: archeological findings provide evidence of sewage disposal and written
medical prescriptions for drugs
•1900 B.C.: Code of Hammurabi (the famous king of Babylon) created; includes laws for
physicians and health practices
•1500 B.C.: Book of Leviticus written; includes guidelines for personal cleanliness and
sanitation
•1500B.C. - Mosaic Law: Personal, food and camp, hygiene, segregating lepers, overriding
duty of saving of life (Pikuah Nefesh) as religious imperatives.
B. Classical Cultures (500b.c.e – 500c.e.)
•5th & 6th centuries b. c. e. : Evidence that Greek men participated in games of strength and
skill and swam in public facilities.
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•Greeks were involved in practice of community sanitation; involved in obtaining water
from sources far away and not just local wells
•Romans were community minded; improved on community sanitation of Greeks; built
aqueducts to transport water from miles away; built sewer systems; created regulation for
building construction, refuse removal, and street cleaning and repair; created hospitals as
infirmaries for slaves
•Christians created hospitals as benevolent charitable organizations • 476 c. e. :
Roman Empire fell and most public health activities ceased.
C. Middle Ages (500–1500c.e)
•500–1000 c. e. (Dark Ages): Growing revulsion for Roman materialism and a
growth of spirituality; health problems were considered to have both spiritual
causes and spiritual solutions, a time referred to as the spiritual era of public
health
•Failure to take into account the role of the physical & biological environment in
the causation of communicable diseases resulted in many unrelenting epidemics
in which millions suffered and died.
•Deadliest epidemics were from plague (“Black death”) occurred in 543c.e. and
1348c.e. (this one killed 25 million; half of population of London lost and in some
parts of France only 1 in 10 survived).
•1200c. e.: More than 19,000 leper houses.
•Other epidemics of period: Smallpox, diphtheria, measles, influenza,
tuberculosis, anthrax, & trachoma.
•1492c.e.: Syphilis epidemic was last epidemic of the period.
D. Renaissance and Exploration (1500–1700c.e.)
•Rebirth of thinking about the nature of world and humankind
•Belief that disease was caused by environmental, not spiritual, factors; for example, the
term malaria, meaning bad air, is a direct reference to humid or swampy air.
•Observation of ill led to more accurate descriptions of symptoms and outcomes of
diseases; observations led to first recognition of whooping cough, typhus scarlet fever,
and malaria as distinct and separate diseases.
•1662: John Graunt published the Observations on the Bills of Mortality, which was the
beginning of vital statistics.
•Epidemics (e.g. smallpox, malaria, and plague), still rampant; plague epidemic killed
68,596 (15% of the population) in London in 1665.
•Explorers, conquerors, and merchants and their crews spread disease to colonists and
indigenous people throughout the New World.
Late 18th Century
•1796: Dr. Edward Jenner successfully demonstrated smallpox vaccination.
19th Century
•1840s: Edwin Chadwick (England), a Poor Law Commissioner, conducted an inquiry
into the causes of poverty which concluded that people often became poor because of ill
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health due to a bad environment. He believed that improving sanitation was the key to
breaking this vicious cycle. Chadwick led a vigorous campaign for change which
eventually won over the establishment, resulting in the Public Health Act 1848.
•1848: England enacted a Public Health Act that provided for the appointment of
Inspectors of Nuisances – the forerunners of today's environmental health
practitioners/Public Health Officers
•1849 – 1854: London cholera epidemics.
•1850: Modern era of public health begins.
•1854: Snow had pump handle removed from Broad Street pump.
•1854: Florence Nightingale, modern nursing and hospital reform – Crimean War
•1859: Charles Darwin publishes On the Origin of Species.
•1863: Pasteur proposed germ theory.
•1875–1900: Bacteriological period of public health.
•1876: Robert Koch discovers anthrax bacillus.
•1879: Neisser discovers gonococcus organism.
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•
1880: Typhoid bacillus discovered (Laveran); leprosy organism (Hansen); malaria
organism (Laveran).
•1882: Robert Koch discovers the tuberculosis organism, tubercle bacillus.
•1883: Robert Koch discovers bacillus of cholera.
•1883: Louis Pasteur vaccinates against anthrax.
•1884: Diphtheria, staphylococcus, streptococcus, tetanus organisms identified
•1890: Anti-tetanus serum (ATS)
•1894: Plague organism discovered (Yersin, Kitasato); botulism organism (Van
Ermengem).
20th Century
•1900: Reed announced that yellow fever was transmitted by mosquitos.
•1923: Health Organization of League of Nations
•1926: Pertussis vaccine developed
•1928: Alexander Fleming discovers penicillin
•1948: World Health Organization founded.
•1952: Development of polio vaccine.
•1977: WHO adopts Health for all by the year 2000
•1977: 1st President of Kenya, H.E. Jomo Kenyatta issued a gazette notice effectively
changing the name “Health Inspector” and “Sanitary Inspector” to Public Health Officer
•1978: Alma-Ata Conference on Primary Health Care
•1979: WHO declares eradication of smallpox achieved
•1981: First recognition of cases of acquired immune deficiency syndrome (AIDS).
•1998: WHO Health for All in the Twenty-first Century adopted.
5.2 Titles commonly used for Public Health/Environmental Health Practitioners
•The legal title used will depend on the definitions found in local legislation/jurisdiction.
•Some past/historic titles include inspector of nuisances, sanitarian, and sanitary inspector.
•Other titles that currently exist include public health officer, health officer, health
inspector, environmental health officer/specialist/practitioner/professional and health
official.
•Eventually the title was standardized across all UK local authorities as 'Sanitary
Inspector'. An Act of Parliament later changed the title to 'Public Health Inspector’.
•An Inspector of Nuisances was the title of an office in several English-speaking
jurisdictions. In many jurisdictions this term is now archaic, the position and/or term
having been replaced by others.
•The first Inspector of Nuisances appointed by a UK local authority Health Committee
was Thomas Fresh in Liverpool in 1844.
5.3 Pioneers of Public Health 1.
Hippocrates: 400 B.C.
•Whereas many attempted to explain disease occurrence from a supernatural viewpoint,
Hippocrates did so from a rational viewpoint.
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•In his essay entitled “On Airs, Waters, and Places,” Hippocrates suggested that
environmental and host factors such as behaviours might influence the development of
disease.
2. John Graunt: 1662
•John Graunt, a London haberdasher and councilman published a ground-breaking
analysis of mortality data in 1662.
•This publication was the first to quantify patterns of birth, death, and disease occurrence,
noting disparities between males and females, high infant mortality, urban/rural
differences, and seasonal variations.
3. William Farr: 1800s • William Farr built upon Graunt’s work by systematically collecting
and analyzing Britain’s mortality statistics.
•Farr, considered the father of modern vital statistics and surveillance, developed many of
the basic practices used today in vital statistics and disease classification.
•He concentrated his efforts on collecting vital statistics, assembling and evaluating those
data, and reporting to responsible health authorities and the general public.
4. Ignaz Semmelweis: 1800s
•Ignaz Semmelweis was born in 1818 and began as a student in law school until he left his
studies to pursue training in medicine.
•He specialized in obstetrics and became interested in a major clinical and public health
problem of the day – childbed fever, also known as puerperal fever (the word “puerperal”
means related to childbirth or to the period after the birth).
•In the early 19th century, childbed fever was a major cause of death among women
shortly after childbirth, with mortality rates from childbed fever as high as 25%.
•Many theories of the cause of childbed fever were popular at the time including
atmospheric toxins, “epidemic constitutions” of some women, putrid air, solar and
magnetic influences.
•This period was a time of growing interest in pathologic anatomy.
•Because the cause of childbed fever remained a mystery, great interest arose in
correlating the findings at autopsies of women who had died of the disease with the
clinical manifestations characterized them before their deaths.
•Semmelweis was placed in charge of the first obstetrical clinic of the Allgemeine
Krankenhause (General Hospital) in Vienna in July 1846. At that time, there were two
obstetrical clinics, the First and the Second.
•Pregnant women were admitted for childbirth to the first clinic or the second clinic on
alternating 24-hour basis.
•The first clinic was staffed by physicians and medical students and the second clinic by
midwives.
•Physicians and medical students began their days performing autopsies on women who
had died from childbed fever; they then proceeded to provide clinical care for women
hospitalized in the First Clinic for childbirth.
•The midwives staffing the second clinic did not perform autopsies.
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•
•Semmelweis had been moved by mortality rates in the two clinics in 1842.
•Mortality in the First clinic was higher than twice as high as the second clinic- 16%
compared with 7%.
Semmelweis came to believe that mortality was higher in first clinic than in the second
clinic because the physicians and medical students went directly from the autopsies to
their patients.
•Many of the women in labor had multiple examinations by physicians and by medical
students learning obstetrics. Often these examinations traumatized the tissues of the
vagina and uterus.
•Semmelweis suggested that the hands of physicians and medical students were
transmitting disease- causing particles from the cadavers to the women who were about to
deliver.
•His suspicions were confirmed in 1847, when his friend and colleague Jakob
Kolletschka died from infection contracted when he accidentally punctured with a
medical student’s knife while performing autopsy.
•The autopsy on Kolletschka showed pathology very similar to that of women (yet he was
a man) who were dying from childbed fever.
•Semmelweis concluded that physicians and medical students were carrying the infection
from the autopsy room to the patients in the first clinic and this accounted for high
mortality rates from childbed fever in the first clinic.
•Mortality rates in the second clinic remained low because the midwives who staffed the
second clinic had no contact with the autopsy room.
•Semmelweis therefore developed and implemented a policy for the physicians and
medical students in the first clinic, a policy designed to prevent childbed fever.
•He required the physicians and medical students in the first clinic to wash their hands and
to brush under their fingernails after they had finished autopsies and before they came in
contact with any of the patients.
•Mortality in the first clinic dropped from 12.2% to 2.4%, a rate comparable to that seen in
the second clinic.
•When Semmelweis was later replaced by an obstetrician who did not subscribe to
Semmelweis’s theories and who therefore eliminated the policy of required hand
washing, mortality rates from childbed fever rose again in the first clinic- further
evidence supporting casual relationship.
•Unfortunately, for many years Semmelweis refused to present his findings at major
meetings or to submit written reports of his studies to medical journals.
•His failure to provide supporting scientific evidence was at least partially responsible for
the failure of medical community to accept his hypothesis of causation of childbed fever
and his proposed intervention of hand washing between examinations of patients.
•Among other factors that fostered resistance to his proposal was the reluctance of
physicians to accept the conclusion that by transmitting the agent responsible for childbed
fever, they had been inadvertently responsible for the death of so many women.
•In addition, physicians claimed that washing their hands before seeing each patient would
be too time-consuming.
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•Another major factor was that Semmelweis was, to say the least, undiplomatic and had
eliminated many senior figures in medicine.
•As a consequence of all these factors, many years passed before a policy of hand washing
was adopted.
•The lessons of this story for successful policy- making are still relevant today to the
challenge of enhancing both public and professional acceptance of evidence- based
prevention policies.
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•
These lessons include
•the need for presenting supporting scientific evidence for a proposed intervention,
•the need for implementation of the proposed intervention to be perceived as feasible, and
•the need to lay the necessary groundwork for the policy, including garnering professional
as well as community and political support.
•Years later, the major cause of childbed fever was recognized to be a streptococcal
infection.
•Semmelweis’s major findings and recommendations ultimately had world-wide effects on
the practice of medicine.
•Amazingly, his observations and suggested interventions preceded any knowledge of the
germ theory.
5. Edward Jenner
•Edward Jenner was born in 1749 and became very interested in the problem of smallpox,
which was a worldwide scourge.
•In the late 18th century, 400,000 people died of smallpox each year and a third of the
survivors became blind with corneal infections.
•It was known that those who survived smallpox were subsequently immune to the disease
and consequently it was a common practice to infect healthy individuals with smallpox by
administering to them material taken from smallpox patients, a procedure known as
variolation.
•However, this was not an optimal method: some variolated individuals died from the
resulting smallpox, infected others with smallpox and developed other infections.
•E. Jenner was interested in finding a better, safer approach to preventing smallpox.
•He observed, as had other people before him, that dairy maids, the young women whose
occupation was milking the cows, developed a mild disease called cowpox. Later, during
smallpox outbreak, smallpox appeared not to develop in these young women.
•In 1768, Jenner heard a claim by the dairy maid, “I can’t take the smallpox for I have
already had the cowpox.” These data were observations and were not based on any
rigorous study. But Jenner became convinced that cowpox could protect against smallpox
and decided to test his hypothesis.
•E. Jenner performed the 1st vaccination in 1796. (The term “vaccination” is derived from
vacca, the Latin word for “cow”). In this year, Jenner administered cowpox material to an
8 year old “volunteer”, James Phipps.
•Jenner was so convinced that cowpox would be protective that 6 weeks later, in order to
test his conviction, he inoculated the child with material that had just been taken from a
smallpox pustule. The child did not contract the disease.
•We shall not enter into argument on ethical issues and implications of this experiment
now. (Clearly Jenner did not have to justify his study before an institutional review
board!).
•In any event, the results of the 1st vaccination and of what followed were the savings of
literally millions of people throughout the world from disability and death caused by the
scourge of smallpox.
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•
•The important point is that Jenner knew nothing about viruses and the biology of the
disease.
He operated purely on observational data that provided him with the basis for a
preventative intervention.
•In 1967, the World Health Organization (WHO) began international efforts to eradicate
smallpox using vaccinations with vaccinia virus (cowpox).
•It has been estimated that, until that time, smallpox afflicted 15 million people annually
throughout the world, of who 2 million died millions of others were left blind or
disfigured.
•In 1980, the WHO certified that smallpox had been eradicated.
•The smallpox eradication program, directed at the time by Dr. D. A. Henderson, is one of
the greatest disease prevention achievements in human history.
•The WHO estimated that 350 million new cases had been prevented over a period of 20
years.
6. John Snow and Cholera
•Snow lived in the 19th century and was well known as the anesthesiologist who
administered chloroform to queen Victoria during childbirth.
•Snow’s true love however was epidemiology of cholera, a disease that was a major
problem in England in the middle of the 19th century.
•John Snow conducted a series of investigations in London that warrant his being
considered the “father of field epidemiology.”
•20 yrs before the development of the microscope, Snow conducted studies of cholera
outbreaks both to discover the cause of disease and to prevent its recurrence.
•In the first week of September 1854, about 600 people living within a few blocks of the
broad street pump in London died of cholera.
•At that time, the registrar general was William Farr had a major disagreement about the
cause of cholera.
•Farr adhered to what was called the miasmatic theory of disease.
•According to miasmatic theory, which was commonly held at the time, disease was
transmitted by a miasm, or cloud, that clung low on the surface of the earth.
•If this were so, we would expect people living in the lower altitudes would be at greater
risk of contracting a disease transmitted by this cloud that those living at higher
elevations.
•Farr collected data to support his hypothesis – The data are quite consistent with his
hypothesis: the lower the elevation, the higher the mortality rate from cholera.
•Snow believed that cholera was transmitted through contaminated water.
•In London at that time, a person obtained water by signing up with one of the water
supply companies just as we do today.
John Snow’s 1st Investigation
•Snow conducted one of his now famous studies in 1854 when an epidemic of cholera
erupted in the Golden Square of London.
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•
•He began his investigation by determining where in this area persons with cholera lived
and worked.
•He marked each residence on a map of the area (i.e spot map).
•Because Snow believed that water was a source of infection for cholera, he marked the
location of water pumps on his spot map, then looked for a relationship between the
distribution of households with cases of cholera and the location of pumps.
He noticed that more case households clustered around Pump A, the Broad Street pump,
than around Pump B or C.
•When he questioned residents who lived in the Golden Square area, he was told that they
avoided Pump B because it was grossly contaminated, and that Pump C was located too
inconveniently for most of them.
•From this information, Snow concluded that the Broad Street pump (Pump A) was the
primary source of water and the most likely source of infection for most persons with
cholera in the Golden Square area.
•There was one significant anomaly – He also noted with curiosity, however, that no cases
of cholera had occurred in a two-block area just to the east of the Broad Street pump
brewery.
•None of the workers in the brewery contracted cholera. As the workers were given a daily
allowance of beer, they did not consume water from the nearby well.
•During the brewing process, the wort (or un-fermented beer) is boiled in part so that hops
can be added. This step killed the cholera bacteria in the water they had used to brew
with, making it safe to drink.
•To confirm that the Broad Street pump was the source of the epidemic, Snow gathered
information on where persons with cholera had obtained their water.
•Consumption of water from the Broad Street pump was the one common factor among
the cholera patients.
•After Snow presented his findings to municipal officials, the handle of the pump was
removed and the outbreak ended.
•The site of the pump is now marked by a plaque mounted on the wall outside of the
appropriately named John Snow Pub.
John Snow’s 2nd Investigation
•This investigation reexamined data from the 1854 cholera outbreak in London.
•During a cholera epidemic a few years earlier, Snow had noted that districts with the
highest death rates were serviced by two water companies – Lambeth Company and the
Southwark & Vauxhall Company.
•At that time, both companies obtained water from the Thames River at intake points that
were downstream from London and thus susceptible to contamination from London
sewage, which was discharged directly into the Thames.
•At one point in time, one of the companies, the Lambeth Company for technical and
nonhealth related reasons, shifted its water upstream, in the Thames to a less polluted part
of the river; the other companies did not move the locations of their water intake.
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•
•Snow reasoned therefore, from his hypothesis of contaminated water causing cholera, the
mortality rate would be lower in people getting water from the Lambeth Company than in
those obtaining their water in the other companies.
•He carried out what we call today “Shoe leather technology”- going from house to house,
counting all deaths from cholera in each house, and determining which company supplied
water to each house.
•The houses served by Southwark and Vauxhall Company, which was getting its water
from a polluted part of the Thames, recorded a higher death rate (315 deaths per 10,000
houses).
•In homes supplied by the Lambeth Company which had relocated its water intake, the
rate was only 38 deaths per 10,000 houses.
His data were so convincing that they led Farr, the Registrar General, to require the
registrar of each district in south London to record which water company supplied each
house in which a person died in cholera.
•Remember that, in Snow’s day, the enterotoxic Vibrio cholera was unknown. Nothing
was known about the biology of the disease.
•Snow’s conclusion that contaminated water was associated with Cholera was entirely
based on observational data.
•Thus, with no knowledge of the existence of microorganisms, Snow demonstrated
through epidemiologic studies that water could serve as a vehicle for transmitting cholera
and that epidemiologic information could be used to direct prompt and appropriate public
health action.
•The point is that, although it is extremely important for us to maximize our knowledge of
the biology and pathogenesis of the disease, it is not always necessary to know every
detail of the pathogenic mechanism to be able to prevent a disease.
end
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