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Lecture at Bayero University Kano Senate Hall on 7th February 2014
by Professor Omar Hasan Kasule MB ChB (MUK), MPH (Harvard), DrPH (Harvard)
Faculty of Medicine King Fahad Medical City
Public Health as Health
Promotion, Health Protection, and Disease Prevention
§ Public
health is the sum of all official (government) efforts to promote, protect, and
maintain health.
§ Public
health has 3 main paradigms: health promotion, health protection, and disease
prevention.
§ Health promotion: physical
fitness and exercise, good nutrition, avoiding addictions (tobacco, alcohol,
and drugs), mental health, and health education.
§ Health protection: avoiding
unintentional injury, occupational health and safety, food and drug safety.
§ Disease prevention: vaccination,
preventive clinical services, and specific preventive measures targeted at
disease risk factors.
Public Health as Social
Intervention
§ The
discipline alternates between holistic social interventions and medical
technological interventions depending on the challenges.
§ In
ancient civilizations public health was a holistic approach to social
improvement with limited technological intervention
§ In
the 19th century public health was a social interventions involving
physicians, social workers, engineers, lawyers, and other social activists.
§ Health
improvements in Europe and the US in the 19th century can be
attributed to social interventions. The medical technology alternative was not
yet developed.
Public Health as Medical
Technological Interventions
§ By
the early 20th century the bio-medical model had become predominant and
thenceforward public health practitioners became physicians only relying on
curative medicine and the holistic social interventions were relatively marginalized.
§ The
biomedical model was very successful with infectious diseases but failed to
control chronic diseases like cancer and heart disease.
§ Chronic
non communicable diseases that cannot be cured but are preventable have forced
us to return to the social intervention modality
Public Health in Ancient
Civilization: Holistic Social Interventions 1
§ Mesopotamia:
The Hammurabi code instituted some public health measures.
§ Egypt:
Drainage systems were known in the middle Egyptian Kingdom (2000-2700 BC).
§ India:
Archeological findings in India show that in about 2000 BC bathrooms and drains
in homes and sewers at street level.
Public Health in Ancient
Civilization: Holistic Social Interventions 2
§ Greece:
In 1600 BC Myceans in Crete had toilets, flushing systems, and sewers. The
Greeks engaged in sports and exercise that are very modern forms of health
promotion.
§ Roman
period (500 BC to 500 CE): Romans improved Greek city water systems. The Romans
built sewage systems, regulated building construction, refuse collection,
street cleaning, and street repair.
§ The
Muslim civilization made many contributions to public health: hygiene, social
welfare, etc. This will require a separate presentation.
Public Health in the European
Middle Ages
§ There
was little development of public health services in Europe in the Middle Ages (500
– 1500 CE) and the post reformation pre-industrial era (1500 – 1850 CE).
§ Middle
ages: Failure to understand the environmental basis of disease led to repeated
epidemics
§ Plague
epidemics in 543, 1348, and 1664 CE. The 1348 plague, called the Black Death,
killed 25 million people.
§ Other
epidemics were: smallpox, diphtheria, measles, influenza, tuberculosis,
anthrax, and trachoma.
§ Syphilis
started in 1492 CE and assumed near epidemic proportions
Public Health in the European
Renaissance and Industrial Revolution
§ The
renaissance and age of exploration (1500-1700 CE): Rapid exchange of ideas and
spread of diseases.
§ It was realized that for some diseases like
malaria (bad air) the environment was an important factor. The epidemics of
smallpox, malaria, plague still occurred.
§ Industrial
era (18th and 19th centuries): Rapid urbanization led to crowded unsanitary
living conditions. Epidemics still occurred in the crowded cities.
§ The
predominant theory for disease causation was the miasma theory which assumed
that vapors or miasma were the cause of disease.
Development of Public Health in
the UK: Reawakening 1
§ In
the Victorian era (1837-1902) Britain became an industrial power with
unprecedented wealth.
§ There
was marked decline in mortality from infectious disease that is attributed to
improved nutrition and standards of living.
§ The
Victorian era had many public health problems arising out of rapid industrialization
and the rural-urban exodus.
§ Awakening:
The cholera epidemics of 1831-2 and 1865-66 led to a more serious interest in
public health.
Development of Public Health in
the
UK: Reawakening 2
§ Sir
Edwin Chadwick (1800-1890 CE) Secretary of the Poor Commission in 1842
published his ‘Report on the Sanitary Conditions of the Laboring Population
based on extensive field surveys. The Chadwick report emphasized the link
between dirt, crowding, and disease.
§ Following
the passage of the Public Health Act of 1848. Edwin Chadwick became a member of
the General Health Board that was concerned with sanitation and sewage
disposal.
§ Due
to his strong advocacy for public health that conflicted with vested interests,
Chadwick was forced to retire at the early age of 54.
Development of Public Health in
the UK: sanitation, housing, school health
§ The
landmark legislation by the Public Health Acts of 1872 and 1875 established a
sanitary authority in every district.
§ Housing
laws of the 1870s included health codes.
§ In
1872 local authorities were required to appoint a medical officer of health
(MOH) whose work was mostly in sanitation and disease control.
§ School
health programs started from 1890.
Development of Public Health in
the UK: home visits, sanitaria, milk hygiene, clean water
§ Measures
were taken to decrease the high infant mortality rate by visits to homes.
§ Sanitaria
were established for tuberculosis patients with emphasis on rest and open air
as methods of treatment.
§ Pasteurization
helped decrease TB transmission.
§ By
the end of the 19th century clean water supplies were available for all.
§ Sewage
disposal systems
Development of Public Health in
the UK: biomedical interventions
§ The
scope of public health in the 20th century changed
§ The
germ theory of disease that became popular in the closing years of the 19th
century narrowed the focus of public health to the infectious disease model
leaving out aspects that we know today to be important for public health.
§ This
model is still dominant and has found its challenge in heart disease and cancer
§ Biomedical
interventions vs human will and human habits
Development of Public Health in
the US: The US Civil War
§ US
civil war was an eye opener” more soldiers from both sides died of disease than
of bullets.
§ State
health boards were established in Massachusetts 1869, California 1870, District
of Columbia 1871, Virginia 1872, Minnesota 1872, and Maryland 1974.
§ Congress
created a National Board of Health in 1879 following a yellow fever epidemic in
the south of the US.
Development of Public Health in
the US: The American-Spanish War
§ The
American-Spanish of 1898 fought in both Cuba and the Philippines: toll of death
due to infectious disease was very high.
§ Program
against yellow fever was started in Cuba and a Tropical Diseases Bureau was set
up in the Philippines.
§ An
intensive campaign again mosquitoes led to control of yellow fever and enabled
the completion of the Panama Canal whose construction had been abandoned
because of disease.
§ Efforts
on tropical diseases within the US also started. The Rockefeller Foundation,
starting in 1909, worked on control of hookworm infestation in the south of the
US.
Development of Public Health in
the US: World War 1 and 2
§ The
First World War: many young men called up for service had to be rejected
because of poor health. Renewed concern with public health started
§ The
Second World War: 40% of the young men called up were declared unfit to serve
in the armed forces for poor health.
§ Youth
health problems persisted in the Korean and Vietnam wars
Development of Public Health in
the US: Social organization 1
§ Industrial
growth in the late 19th century, urban health problems increased and cities
were hardly coping. As a response to the urban problems, public health was
transformed into a social reform movement.
§ Organizations
were formed to fight for improved housing, abolition of child labor, provision
of maternal and child health services, and promotion of temperance.
§ By
1937 the average life expectancy was 59.7 years.
Development of Public Health in
the US: Social organization 2
§ 1882
- The American Red Cross formed
§ 1902
– The National Committee for Mental Hygiene
§ 1902
- The National Association for the Study and Prevention of Tuberculosis
§ 1904
- The National Tuberculosis Association was formed
§ 1905
- The American Social Hygiene Association
§ 1912
- The American Public Health Association (APHA)
§ 1913
- The American Cancer Society in 1913
§ 1919
– The American Society for the Control of Cancer in 1919.
Development of Public Health in
the US: Public Health legislation
§ 1856
- New York passed a law on adulteration of milk
§ 1878
- The Port Quarantine Act was passed
§ 1890
- Pasteurization of milk started in 1890.
§ 1906
- The Pure Food and Drugs Act was passed in 1906
§ 1910
- New York State passed the workmen compensation
§ 1923
- The major achievement of this era was perhaps the prohibition of alcohol
which was accompanied by decline of alcoholism and alcohol—related disease.
Development of Public Health in
the US: Public Health actions
§ 1864
– First sanitary survey in New York
§ 1891
- Milk inspection started
§ 1895
– Septic tanks started
§ 1895
– First nurse appointed
§ 1910
- First occupational health clinic was set up in 1910.
§ 1912
- role of the United States Public Health Service was expanded to include
investigation of disease and sanitation
Development of Public Health in
the US: Bacteriological period of public health 1875-1900.
§ The
leading causes of death at the close of the 19th century were communicable
diseases: influenza, pneumonia, TB, GIT infections, typhoid, malaria,
diphtheria, pellagra, and rickets.
§ Death
rates from infectious diseases started falling before vaccination and
antibiotics were available mainly due to environmental and social improvements
§ By
the 1920s public health was dominated by medical persons. Sanitary and other
professions like municipal engineers, lawyers, and social reformers who had
been part of the public health reform movement took a lower profile.
Development of Public Health in
the US: Bacteriological period of public health 1875-1900.
§ Towards
the end of the 19th century, bacteriology gave a new impetus to public health
by establishing the bacteriological approach which emphasized the disease
orientation.
§ In
1862 Louis Pasteur proposed the germ theory of disease.
§ 1882
Robert Koch proposed criteria for diagnosis of bacterial disease.
§ There
was a decline in public health in the post-war era due to various reasons. The
focus on bacteriology emphasized curative medicine using drugs to eliminate
disease without the necessity for public health measures
Development of Public Health in
the US: Early 20th century
§ In
1900 Major Walter Reed announced his discovery that mosquitoes transmitted
yellow fever
§ In
the period 1946-1960s hospital construction increased under the 1946
Hill-Burton Act (National Hospital Survey and Construction Act).
§ The
discovery of the polio vaccine gave a boost to infectious disease control by
immunization.
§ President Eisenhower’s heart attack stimulated
the exercise movement.
Development of Public Health in
the US: Period of Social Engineering (1960-1980):
§ In
the 1960s the Great Society and War against Poverty programs resulted into
increased government funding for public health.
§ The
federal government became involved payment for medical care and environmental
regulation. The Medicaid and medicare bills were passed in 1965. They increased
access to health services but had the unwanted effect of increasing the cost of
health services.
§ Schools
of public health responded by offering new training programs in health policy
and management, mental health, population control, environmental health, and
international health. Enrolment in public health schools increased
tremendously.
§ By
the 1970s public health programs of various kinds were offered by states.
Development of Public Health in
the US: Period of Health Promotion (1980-1990)
§ By
the mid 1970s health promotion and disease prevention were recognized as
priorities.
§ The
Centers for Disease Control concluded in 1975 that about 48% of premature deaths
were due to lifestyle (lack of exercise, high fat diet, smoking, and stress).
§ In
the 1980 the US published 226 objectives for the nation in the field of disease
prevention and health promotion divided into three categories: preventive
services, health protection, and health promotion.
§ The
objectives were based on the 1979 Surgeon-General’s Report titled ‘Healthy
People: National Health Promotion and Disease Prevention Objectives’
Tuberculosis History: mortality
and treatment
§ Tuberculosis
has claimed its victims throughout much of known human history. It reached
epidemic proportions in Europe and North America during the 18th and 19th
centuries, earning the sobriquet, "Captain Among these Men of Death."
Then it began to decline.
§ identification
of the tubercle bacillus as the etiologic agent by Robert Koch in 1882
§ BCG
vaccination was widely employed following World War I.
§ The
modern era of tuberculosis treatment and control was heralded by the discovery
of streptomycin in 1944 and isoniazid in 1952.
Daniel TM. The
history of tuberculosis.
Respir Med. 2006 Nov;100(11):1862-70. Epub 2006 Sep 1.
Tuberculosis History: controversy
about the role of social reform vs technology
§ Tuberculosis
(TB) began to decline in the Western world in the mid- to late 1800s. In the
United States, the disease receded until the mid-1980s
§ TB
epidemic sparked a controversy regarding the relative value of targeted public
health measures vs broad social reform.
§ Historical
and demographic studies of Thomas McKeown - thesis that clinical and primary
prevention efforts had little effect on TB mortality.
§ The
present author from analysis of historical information concludes that public
health measures, along with other factors, led to falling rates of TB mortality
beginning in the late 19th century.
Fairchild AL, Oppenheimer
GM. Public health nihilism vs pragmatism: history,
politics, and the control of tuberculosis. Am
J Public Health. 1998 Jul;88(7):1105-17.
Tuberculosis History: 19th
century Decline of mortality
§ In
1815, one in four deaths in England was due to "consumption". By
1918, one in six deaths in France was still caused by TB. (Wikipedia)
§ By
the 1950s, mortality had decreased nearly 90%.
§ Improvements
in public health began significantly reducing rates of tuberculosis even before
the arrival of streptomycin and other antibiotics
Tuberculosis History: 19th
century Decline of mortality in New York (deaths per 1000 people)
§ 1821
- Blacks 9.6 Whites 5.3;
§ 1830
- Blacks 12.0 Whites 4.4;
§ 1844
- Blacks 8.2 Whites 3.6
§ 1855
- Blacks 12.0 Whites 3.1
§ 1860
- Blacks 6.7 Whites 2.4
§ 1865
- Blacks 6.7 Whites 2.8
Tuberculosis History: 19th
century Decline of mortality in New Orleans (deaths per 1000 people)
§ 1849
- Blacks 5.2 Whites 4.9
§ 1880
- Blacks 6.0 Whites 3.3
§ 1890
- Blacks 5.9 Whites 2.5
Controversy about Effectiveness of BCG for TB Prevention 1
§ The
BCG vaccine has been in use since 1921, but still arouses controversy and
uncertainties.
§ Study
based on a systematic review of the literature in both English and Spanish covering
the period 1948 to 2006
§ The
protective effect of the first dose of the BCG vaccine against tuberculosis in
its miliary and meningeal forms is high.
§ The
results vary in relation to the pulmonary form of the disease, with some
indicating zero effect and others levels of nearly 80%.
§ Research
is being carried out to develop new vaccines that could substitute the BCG or
be used as a booster.
Pereira SM, Dantas
OM, Ximenes R, Barreto ML. [BCG
vaccine against tuberculosis: its protective effect and vaccination policies]. Rev
Saude Publica. 2007 Sep;41 Suppl 1:59-66.
Controversy about Effectiveness of BCG for TB Prevention 1
§ The
protective effect against tuberculosis observed in various studies ranged from
-56% to 98%.
§ Case-control
studies carried out at Nagpur reported moderate effectiveness of BCG
vaccination in prevention of tuberculosis. Its effectiveness was higher against
extra-pulmonary tuberculosis.
§ The
summary protective effects obtained from meta-analysis of trials, cohort
studies and case-control studies of BCG vaccination and tuberculosis were 51
(33-64), 76 (63-85), and 65 (57-72) percent respectively.
§ The
results of the current study and systematic review thus supported arguments
favoring use of BCG vaccine for prevention of tuberculosis
Zodpey SP.The
BCG controversy: a reappraisal of the protective
effect against tuberculosis and leprosy. Indian J Public Health. 2004
Apr-Jun;48(2):70-7.
Controversy about Effectiveness of BCG for TB Prevention 1
§ To
study association between the geographic location (latitude) of studies
evaluating protective effect of BCG vaccine and it's efficacy / effectiveness
against tuberculosis. Study based on literature search
§ The
study recognized an association between geographic locations of studies and
reported protective effects of BCG vaccine against tuberculosis.
Zodpey SP, Shrikhande
SN.The geographic location (latitude) of studies evaluating protective
effect of BCG vaccine and it's efficacy/effectiveness against tuberculosis. Indian
J Public Health. 2007 Oct-Dec;51(4):205-10.
Relation between TB Incidence and
Human Development
§ Objectives.
Assess relationship between the Human Development Index (HDI) and the incidence
of tuberculosis (TB) in 165 countries in the World in the period 2005-2011.
§ Inverse
relation between TB and HDI
§ High
TB incidence was associated with low Human Development Index (P <0.01)
§ The
association varied with time variation of HDI
Castañeda-Hernández DM,
Tobón-García D, Rodríguez-Morales AJ. [Association between tuberculosis incidence and
the Human Development Index in 165 countries of the world]. Rev Peru Med Exp
Salud Publica. 2013 Dec;30(4):560-8.
Malaria
§ Malaria
has been successfully eliminated or greatly reduced in certain areas.
§ Malaria
was once common in southern Europe, but vector control programs, in conjunction
with the monitoring and treatment of infected humans, eliminated it from those
regions.
§ Malaria
was eliminated from most parts of the USA in the early 20th century by such
methods, and the use of the pesticide DDT and other means eliminated it from
the remaining pockets in the South in the 1950s.
§ Several
factors contributed, such as the draining of wetland breeding grounds for
agriculture and other changes in water management practices, and advances in
sanitation, including greater use of glass windows and screens in dwellings.
Infant and Child Mortality
Fig 3.4 page 115 WDR 2014
Non Communicable Diseases
Fig 3.5 page 116 WDR 2014
Relative Cost Benefit Analysis Of Interventions
Fig 2 page 8 WDR 2014
More People Have Mobile Phones Than Toilets
Fig 4.8 page 157 WDR 2014
Theoretical Conclusions
§ The
multi causality of disease
§ The
necessary cause + co factors = sufficient cause
§ It
may be more effective to intervene against the cofactors by social
interventions