Intro to Global Health
What is public health in epidemiological terms?
"One of the efforts to protect, promote and restore the people's health". "It is the combination of sciences, skills and beliefs that is directed to the maintenance and improvement of the health of all the people through collective or social actions"
What is incidence density?
When incidence rates incorporate time into the denominator
Who developed Avermectin and Ivermectin?
William C. Campbell and Satoshi Owura
Who discovered Artemisinin?
Youyou Tu
What is the Public Health Approach?
- Surveillance: What is the problem? - Risk Factor Identification: What is the cause? - Intervention Evaluation: What works? - Implementation: How do you do it?
What are some individual protective measures against mosquito and tick bites?
-Avoid outbreaks -Be aware of peak exposure times and place -Wear appropriate clothing -Check for ticks -Bed nets -Insecticides
What are the four factors of the establishment of the discipline?
-Decision making based on data/evidence (vital statistics, surveillance, outbreak investigations, laboratory science) -Focus on populations rather than individuals -Goal of social justice and equity -Emphasis on prevention rather than cure
What are some global public health approaches?
-Emphasis on health as a public good, justice, equity -Priority on population-based and preventive focus -Belief in a global perspective -Concentration on poorer, vulnerable, undeserved populations -Scientific multidisciplinary and interdisciplinary -Multilevel approaches to interventions -Importance of systems and structures -Participation of multiple stakeholders
What are some vaccination and prevention global responses?
-In 2015, global coverage with the three doses of hepatitis B vaccine in infancy reached 84%. -This has substantially reduced HBV transmission in the first five years of life, as reflected by the reduction in HBV prevalence among children to 1.3%. -However, coverage with the initial birth dose vaccination is still low at 39%. -Although injection drug use is the major route of HCV transmission in some regions, the provision of effective harm reduction services has been inadequate. -Globally, 5% of health-care-related injections remained unsafe. -As a result, an estimated 1.75 million new HCV infections occurred worldwide in 2015.
What is YLD (Years Lived with Disability)?
-Loss of healthy life from disability based on incidence, average duration, and severity. -These assumptions are derived from standard values and projected into the future
What are the Hepatitis A Epidemiology patterns?
-Poor sanitary conditions -Industrialized countries -Closed or semiclosed communities
What are some Hepatitis A risk groups/factors?
-Reportable in the US - incidence 4/100,000. -In 2001, 10,616 cases of HAV infection were reported in the US (considering underreporting and asymptomatic cases: likely 93,000/yr.). -The highest rate of reported disease is among children ages 5 to 14 years; 25% of reported cases are among persons 20 years or younger Risk factors for HAV infection (U.S. / 2002): unknown, 57%; sexual or household contact with a patient who has hepatitis A, 12%; international travel, 9%; male homosexual activity, 8%; injection drug use, 5%; child or employee in a daycare center, 1%; food or waterborne outbreak, 1%; contact with a daycare child or employee, 3%; and other contact with a patient who has hepatitis, 4%.
What are the international sources of data?
-World Health Organization • Infectious Disease • Levels of sanitation and health care • Maternal and child health -United Nations -Individual countries and individual "states" -Specific studies to assess disease • Asthma • Air pollution -Other non‐profit websites that organize data
What are some public health surveillance keywords?
-analysis -interpretation -collection -dissemination -ongoing -systematic -health-related data -linked to public health practice
What are the 17 Neglected Tropical Diseases?
1. Dengue 2. Rabies 3. Blinding trachoma 4. Buruli ulcer 5. Endemic treponematoses (yaws) 6. Leprosy (Hansen disease) 7. Chagas disease 8. Human African trypanosomiasis (sleeping sickness) 9. Leishmaniasis 10. Cysticercosis 11. Dracunculiasis (guinea-worm disease) 12. Echinococcosis 13. Foodborne trematode infections 14. Lymphatic filariasis 15. Onchocerciasis (river blindness) 16. Schistosomiasis (bilharziasis) 17. Soil-transmitted helminthiases (intestinal worms)
Millennium Development Goals summarized?
1. End hunger 2. Universal education 3. Gender equity 4. Child health 5. Maternal health 6. Combat HIV/AIDS 7. Environmental Sustainability 8. Global Partnership
What Determines the Health of a Population in order of importance?
1. Social/Societal Characteristics; Total Ecology 2. Medical Care or Health Services 3. Health Behaviors 4. Genes and Biology
What are the five elements included in IVM?
1. evidence-based decision-making 2. integrated approaches 3. collaboration within the health sector and with other sectors 4. advocacy, social mobilization, and legislation 5. capacity-building
What is an emerging infectious disease?
A newly discovered disease
What is integrated vector management (IVM)?
A rational decision-making process for the optimal use of resources for vector control • No reliance on single method of vector control • Stresses importance of understanding local vector ecology and local patterns of disease transmission • Chooses appropriate vector control tools, from range of options • Uses environmental management strategies to reduce or eliminate vector breeding grounds • Uses improved design or operation of water resource projects
What is Health?
A state of complete physical, mental and social well-being and not merely the absence of infirmity' WHO 1948
What is Global Public Health?
An area for study, research, and practice that places a priority on improving health and achieving equity in health for all people worldwide.
What is a reemerging infectious disease?
An existing disease that has increased in incidence or has taken on new form
What are mortality rates?
Annual mortality rate (per 1,000) = Total No. of deaths from all causes in one year X 1,000/No. of persons in the population at midyear We use the midyear population as an estimate as the true number varies during the year (estimate of rate for large population) We can make this more specific by choosing a subset of the population: • Age‐range specific • Disease specific Examples: Children with pneumonia age 1 - 5 yrs Deaths from pneumonia in children 1‐5yrs of age x 1000/Total No. of children in pop. 1‐5 yrs of age. Different than case‐fatality rate.
Which diseases are triatomine bugs vectors of?
Chagas disease (American trypanosomiasis)
Which diseases are the Aedes mosquitoes vectors of?
Chikungunya Dengue fever Lymphatic filariasis Rift Valley fever Yellow fever Zika
Global Climate Change and its Impact of the Fundamentals of Health?
Climate change will affect, in profoundly adverse ways, some of the most fundamental prerequisites for good health: clean air and water, sufficient food, adequate shelter and freedom from disease
Which diseases are ticks vectors of?
Crimean-Congo haemorrhagic fever Lyme disease Relapsing fever (borreliosis) Rickettsial diseases (spotted fever and Q fever) Tick-borne encephalitis Tularaemia
What are the Sustainable Development Goals?
GOAL 1: No Poverty GOAL 2: Zero Hunger GOAL 3: Good Health and Well-being GOAL 4: Quality Education GOAL 5: Gender Equality GOAL 6: Clean Water and Sanitation GOAL 7: Affordable and Clean Energy GOAL 8: Decent Work and Economic Growth GOAL 9: Industry, Innovation and Infrastructure GOAL 10: Reduced Inequality GOAL 11: Sustainable Cities and Communities GOAL 12: Responsible Consumption and Production GOAL 13: Climate Action GOAL 14: Life Below Water GOAL 15: Life on Land GOAL 16: Peace and Justice Strong Institution GOAL 17: Partnerships to achieve the Goal
What are the Millennium Development Goals?
Goal 1: Eradicate extreme poverty and hunger Goal 2: Achieve universal primary education Goal 3: Promote gender equality and empower women Goal 4: Reduce child mortality Goal 5: Improve maternal health Goal 6: Combat HIV/AIDS, malaria and other diseases Goal 7: Ensure environmental sustainability Goal 8: Develop a Global Partnership for Development In 2009, an IOM committee, which included former NIH head, Harold Varmus, recommended that $13 billion be invested in fulfilling health-related Millennium Development Goals put forward by the United Nations, with another $2 billion for combating injuries and non-communicable conditions, such as heart disease.
What do cause-of-death statistics do?
Help health authorities determine the focus of their public health actions.
What are Human African trypanosomiasis (HAT)?
Improved trapping methods and control strategies for the main HAT vector, the tsetse fly (e.g. bait technology, odor release systems and trapping materials). It also has exploitation of the genome of the tsetse fly, Glossina morsitans, for development of new vector control tools.
What is a case?
Individual with a particular disease
What is the convergence model?
It examines the human-microbe interface in the context of an array of factors: genetic and biological; physical and environmental; ecological; and social, political, and economic
Which diseases are the Culex mosquitioes vectors of?
Japanese encephalitis Lymphatic filariasis West Nile fever
Global Environmental Change?
Large-scale and global environmental hazards to human health include climate change, stratospheric ozone depletion, loss of biodiversity, changes in hydrological systems and the supplies of freshwater, land degradation and stresses on food-producing systems.
Which diseases are sandflies vectors of?
Leishmaniasis and Sandfly fever (phelebotomus fever)
Which diseases are the Anopheles mosquitoes vectors of?
Malaria and Lymphatic filariasis
Why do we need to know the reasons people die?
Measuring how many people die each year and why they died is one of the most important means for assessing the effectiveness of a country's health system.
Which disease are black flies vectors of?
Onchocerciasis (river blindness)
What is eradication?
Permanent reduction to zero of the worldwide incidence of infection caused by a specific agent. Ex: smallpox
Which diseases are fleas vectors of?
Plague (transmitted by fleas from rats to humans) and Rickettsiosis
What is elimination of disease?
Reduction to zero of the incidence of a specified disease. Ex: neonatal tetanus
What is elimination of infections?
Reduction to zero of the incidence of infection caused by a specific agent. Ex: measles, poliomyelitis
Which disease are aquatic snails vectors of?
Schistosomiasis (bilharziasis)
Which diseases are tsetse flies vectors of?
Sleeping sickness (African trypanosomiasis)
What is extinction?
Specific infectious agent no longer exists
What is the growing concern about climate change?
That it could alter transmission patterns of vector-borne diseases such as malaria and dengue (changes in temperature or rainfall impact vector habitats).
What is prevalence?
The number of affected persons present in the population at a specific time out of the total number of persons in the population at that time Prevalence per 1,000 = No. of cases of disease present in population at a specific time x 1,000 No. of persons in the population at that time
What is a case fatality rate?
The proportion of persons with a particular condition (cases) who die from that condition
What is control?
The reduction of disease incidence, prevalence, morbidity or mortality. Ex: diarrheal diseases
What do neglected infections of poverty in the US affect?
They disproportionately affect impoverished and underrepresented minority populations.
What is the Neglected Infections of Impoverished Americans Act 2011?
This bill requires the Department of Health and Human Services to report to Congress on the epidemiology of, impact of, and appropriate funding required to address neglected diseases of poverty, including Chagas disease, cysticercosis, toxocariasis, toxoplasmosis, trichomoniasis, soil transmitted helminth infection, and other related diseases. The report should provide the information necessary to guide future health policy to evaluate the current state of knowledge concerning such diseases and address the threat of such diseases
What is the goal of Public Health Surveillance?
To provide information that can be used for health action by public health personnel, government leaders, and the public to guide public health policy and programs
What are the major neglected infections?
Toxocariasis,strongyloidiasis, ascariasis, cysticercosis, leptospirosis, Chagas disease, leishmaniasis, trench fever, dengue fever, cytomegalovirus (CMV), toxoplasmosis, and syphilis.
Which disease are lice vectors of?
Typhus and louse-borne relapsing fever
What is the etiology of diarrheal diseases?
Viral, bacterial and parasitic (most frequent rotavirus and enteropathogenic E. coli)
What are prions?
abnormal, pathogenic agents that are transmissible and are able to induce abnormal folding of specific normal cellular proteins called prion proteins that are found most abundantly in the brain
What are Health Determinants?
factors that contribute to the generation of a trait or condition of health. In Epidemiology, it is the EXPOSURE Ex: Risk Factors
What are viruses?
living organisms that cannot replicate without a host cell.
What is dehydration?
most severe threat - loss of H2O and Na, CL, K, bicarbonate through liquid stools, vomit, sweat, urine and breathing • Moderate dehydration: thirst, restless, irritable behavior, decreased skin elasticity, sunken eyes • Severe dehydration: symptoms more severe, shock, diminished consciousness, lack of urine output, cool, moist extremities, rapid feeble pulse, low or undetectable blood pressure, and pale skin.
What are parasites?
organisms that live in or on another organism (its host) and benefits by deriving nutrients at the host's expense. In other words, an organism that lives in or on another organism and takes nourishment from that organism
What is bacteria?
round, spiral, or rod-shaped single-celled prokaryotic microorganisms that typically live in soil, water, organic matter, or the bodies of plants and animals, that make their own food especially from sunlight or are saprophytic or parasitic, are often motile by means of flagella, reproduce especially by binary fission, and include many important pathogens
What is International Health?
the application of the principles of public health to problems and challenges that affect low and middle-income countries and to the complex array of global and local forces that influence them
How do you define health?
the condition of being sound in body, mind, or spirit; especially: freedom from physical disease or pain
What is Public Health?
the science and art of preventing disease, prolonging life, and promoting physical health and mental health and efficacy through organized community efforts towards a sanitary environment
What does the 'Global' stand for in 'Global Health'?
the scope of problems, not their location. 'Global health' focuses on domestic health disparities as well as cross national border issues.
Disease Prevention through Healthier Environments?
• 'Environmentally induced' disease burden in developing countries > than in developed countries • Children bear highest death toll (>4 million yearly) • Infant death rate from environmental causes 12x higher in developing than in developed countries
What is the clinical aspect for diarrheal diseases?
• 3-23% of diarrheal illnesses persist > 2 weeks • Multiple episodes/yr result in stunted growth due to loss of appetite and nutrient malabsorption (increases susceptibility to diarrheal diseases)
What is a proportion?
• A specific type of ratio • All those included in the numerator must be part of the denominator - just like the expression of a fraction Example: • Proportion of population with diagnosed hypertension • Number of individuals with hypertension/ Number of individuals in the population times 100 • Answer often read as a percent
Developing Countries?
• About 80% of the world's population lives in areas labeled' developing countries' • Some of these countries have transformed to patterns of health typical for 'developed' countries, but other features of underdevelopment (high rates of poverty and low educational attainment) remain • In others (Sub-Saharan Africa, central America, islands) the major determinants of health remain with poverty, poor sanitation, low educational attainment
What are the key measures to prevent diarrheal diseases?
• Access to safe drinking-water • Improved sanitation • Exclusive breastfeeding for the first six months of life • Good personal and food hygiene • Health education about how infections spread • Rotavirus vaccination
What is morbidity?
• Any departure, subjective or objective, from a state of physiological or psychological well‐being. • Encompasses disease, injury, and disability. • Can also be used to describe the periods of illness, or the duration of illnesses • Measures of morbidity show the number of persons in a population who become ill (incidence) or are ill at a given time (prevalence).
What are DALY's (Disability‐Adjusted Life Year)?
• Combines time lost due to disability with that due to death • Used to define the "Global Burden of Disease" • DALY = YLL + YLD • Can be expressed as TOTAL, Rate, or Proportion for specific causes and regions
What are some problems with mortality?
• Death certificates are often poorly coded • Cause of death may have multiple contributions, not one • Tremendous variability between different areas • Many countries do not have universal record‐keeping of deaths. • As survival improves with modernization and populations age, mortality measures do not give an adequate picture of a population's health status
What are the epidemiology purposes in public health practice?
• Discover the agent, host, and environmental factors that affect health • Determine the relative importance of causes of illness, disability, and death • Identify those segments of the population that have the greatest risk from specific causes of ill health • Evaluate the effectiveness of health programs and services in improving population health
What is the importance of global public health?
• Diseases do not respect boundaries • Ethical dimension • Health linked with economic and social development in an interdependent world • Implications for global security and safety
What are ways key health issues affect different parts of the world?
• Environmental health • Nutrition • Reproductive health • Child health • Communicable diseases • Noncommunicable diseases • Injuries
What are some facts about diarrheal disease?
• Following pneumonias (1st), diarrheal diseases are the 2nd leading cause of mortality (1.5 million/yr.) in children <5 years (80% < 2 yrs. of age) cause of 6.9% of deaths overall • Globally about two billion cases / yr. • Leading cause of malnutrition in children < 5 yr. of age • Primarily affects populations in developing countries - in extreme conditions of poverty - peri-urban dwellers or rural inhabitants
What are some shifts in global health priorities?
• Global situation with regards to HIV/AIDS and tuberculosis dismal • Increasing shift in diseases with global health impact • Rethinking in remediation approaches
What are some facts about Communicable Diseases?
• In 2010, it accounted for 31% of all deaths and 40% of all DALYs in low and middle income countries • Most important burden of disease (50%) in Sub-Saharan Africa. • Make up 22% of all DALYs in South Asia • Disproportionally affect the poor • Have enormous economic consequences (future economic prospect in children, impediments to investments)
What are some factors about drinking water?
• In 2015, 91% of the world's population had access to an improved drinking-water source, compared with 76% in 1990. •2.6 billion people have gained access to an improved drinking-water source since 1990. •4.2 billion people now get water through a piped connection; 2.4 billion access water through other improved sources including public taps, protected wells and boreholes. • 663 million people rely on unimproved sources, including 159 million dependent on surface water. • Globally, at least 1.8 billion people use a drinking water source contaminated with feces
What is incidence?
• Incidence = number of new cases of a disease occurring in a population during a specified period of time - A measure of risk (probability) - Denominator of incidence represents the number of persons at risk during that time. Anyone in the denominator must have the potential to become part of the numerator (again, like a typical proportion). Ex: Incidence per 1,000 in one year= No. of new cases in a specific period of time (x 1000)/No. of persons at risk to become a case • This is a ratio and a proportion • Not a true rate in the strict sense because time is not part of the denominator. • Time is specified explicitly for the entire time. • Also known as "cumulative incidence" or "incidence proportion"
What is YLL?
• Loss of life from death in a year and evaluating life expectancy lost • Measures life lost based on given deaths in the year
Why is mortality important to measure?
• Many diseases are identified at early stages, some of which will never cause clinical disease. • We may actually increase incidence artificially over time by this earlier trend in diagnosis. Some persons call this "over‐diagnosis", especially with insignificant disease. • Mortality gives one true impact of the disease and the population involved.
What is incidence rate?
• No. of new disease onsets -SUM of persons' time spent in the population • Expressed in person‐time such as person‐years, person‐months, etc. Example: 5 persons followed for 2 years = 10 person‐years; [or 10 persons followed for 1 year]. Another example: • 1) 500/600 p‐yrs or 0.83 case per p‐yr. • 2) 500/(600*1) + (500*2) +(400*3) + (300*4) + (200*5)) = 500/5000 p -yrs or 0.1 case per p‐yr
What is a ratio?
• One number divided by another • No special relationship is required between numerator and denominator, but often exists. • Proportions and rates are specific types of ratios Examples: • Prevalence • Sex Ratio • Maternal Mortality Ratio
What is the global strategic framework for integrated vector management (IVM)?
• Provides a basis for strengthening vector control compatible with national health systems. • Through evidence-based decision-making rationalizes use of human and financial resources and organizational structures • Emphasizes the engagement of communities to ensure sustainability. • Encourages a multi-disease control approach, integration with other disease control measures • Considers and systematically applies range of interventions, often in combination and synergistically
What is morbidity and disability?
• Quality of life is heavily dependent on presence of disability that is determined by the severity of the disability Cultural Concepts of • Disease - organic level per individual • Illness - subjective state of dysfunction i.e. an individual's experience with disease • Sickness - social dysfunction within society beyond the individual • Overall impact of disability in a population depends on: prevalence of disability x extent or severity x duration
Ecosystems, Environmental Changes & Communicable Diseases?
• Rapid population growth, urbanization, economic globalization and migration are major drivers of environmental changes. • Changes in patterns of forestation and deforestation, water tables, water management, agricultural exploitation, patterns of temperature and rainfall. • Ecosystem changes have long-term, secondary impacts on disease control due to loss of biodiversity including rich reservoirs of plants (ethnobotany). • Viral infections such as Dengue, Zika, Chikungunya (CHIKV), Avian Influenza (bird flu), Japanese encephalitis, severe acute respiratory syndrome, (SARS), Yellow fever, West Nile fever, Lassa (hemorrhagic fevers) and other infections and Zoonoses emerge as a result of major demographic changes, rapid urbanization, global travel and environmental change. Conclusion: Ecosystem changes, often rapid and dramatic, are major factors in the persistence, emergence and re-emergence of IDs, particularly vector-borne diseases.
What are some principles in defining health?
• Self‐reported value of life and quality of health can vary tremendously among cultures and individuals. • In EPIDEMIOLOGY‐Definition of health=definition of health outcome=Disease
What are some composite measures of population health?
• Summary measure to compare different populations • Give more weight to early deaths • Death is death no matter what the cause, but disability and comorbidity have large variations from different causes. We need methods of combining them into a common currency
What are rates?
• Tells us how fast disease is occurring in a population • The denominator incorporates a measure of time • Think velocity or speed Example: 60 mph • Time, place and population must be specified for each type of rate. • The term "Rate" is often misused
What are some critical global public health concepts?
• The determinants of health • The measurement of the health status • The importance of culture to health • The global burden of disease • The key risk factors for different health conditions • The demographic and epidemiological transitions • The organization and functions of health systems
What are years of potential life lost?
• This is a measure of premature mortality • Subtract age at death from some predetermined age (usually 65) • Greatest source of premature mortality in the US is unintentional injury and prematurity. In lower income countries, it is childhood communicable disease.
What are some reasons to measure health (and disease) in populations?
• To guide efforts in reducing consequences of disease • Allocation of resources • To see if there are trends within population subsets • To see if certain population‐based interventions are effective (assessment) • Understanding risk factors (and thus leading to possible preventive measures)
What determinants will climate change compromise to?
• Water quality and quantity: by doubling of people living in water-stressed basins by 2050. • Food security: by halving yields from rain-fed agriculture in some African countries by 2020. • Control of infectious disease: by increasing populations at risk of malaria in Africa (170 million by 2030) and of dengue (2 billion by 2080). • Protection from disasters: by increasing exposure to coastal flooding (10 x), and land area in extreme drought (10-30 x).
Viral Hepatitis - A Major GPH Problem?
• caused 1.34 million deaths in 2015 (approx. like TB, > HIV) • deaths due to viral hepatitis are increasing over time (increased by 22% since 2000). • most deaths in 2015 due to chronic liver disease (720,000 deaths due to cirrhosis) and primary liver cancer (470,000 deaths due to hepatocellular carcinoma). • Globally, in 2015, an estimated 257 million people were living with chronic HBV infection, and 71 million people with chronic HCV infection. • The epidemic caused by HBV affects mostly the WHO African Region and the Western Pacific Region
What are standardization of rates?
•Comparing rates across various areas can be problematic if the populations differ substantially. This is especially true if the age structure is different within each area
What are some health effects for global climate change?
•Temperature-related illness and death •Extreme weather- related health effects •Air pollution-related health effects •Water and food-borne diseases •Vector-borne and rodent- borne diseases •Effects of food and water shortages •Effects of population displacement