Introduction to Epidemiology

Identify disease causes and risk factors, study transmission, assess community burden and natural history with baseline incidence, prevalence, and mortality, and inform policy on environmental and genetic issues.

Identify the disease stages—pre disease stage, lead-on stage, and symptomatic stage—and map them to primary, secondary, and tertiary prevention, with dengue prevention, screening, and stroke rehabilitation as examples.

Identify how social, nutritional, and environmental risk factors influence disease mechanisms and progression, exemplified by vitamin D deficiency related osteomalacia and its impact on maternal and infant mortality.

Explain how behavioral factors like excessive fat intake, smoking, and inactivity influence pathogenesis, LDL and HDL imbalances, and fatty plaques that restrict blood flow and raise stroke risk.

Explore host factors shaping disease risk, including genotype, attritional status and BMI, vaccination status, herd immunity, and social behaviors; apply epidemiologic reasoning to identify associations between exposures and disease.

Identify agents of disease across biologic, chemical, and physical categories, including allergens, infectious organisms, toxins, foods, dust, trauma, radiation, heat, cold, and noise, and stressors like anxiety and depression.

Examine how the environment shapes disease risk by affecting host–agent contact and exposure. Assess how sanitation, roads, weather, and social factors influence injury and mortality.

Identify intrinsic and extrinsic risk factors, including genetic and lifestyle elements such as tobacco use, obesity, and alcohol, to guide preventable disease strategies and tailor high-risk group interventions.

The beings model identifies major disease risk-factor categories, noting genetic factors are hard to change and immunologic factors are easier, with vaccines available; the lecture examines each letter.

Explore how biologic factors like gender, age, weight, and bone density, along with behavioral factors such as smoking, drinking, and physical activity, influence health risks.

Investigate how environmental factors include pathogens in communities and physical, chemical or biological harms that affect soil, water, air, and ecosystems where humans, animals and plants live together.

Explore immunologic risk factors and how immune status affects disease susceptibility across age groups and comorbid conditions. Learn how vaccines create individual and herd immunity, underpinning smallpox eradication.

Explore how nutrition influences infection and disease risk, highlighting Burkitt's cross-cultural findings on high dietary fiber reducing diabetes and hypertension through the dietary fiber hypothesis.

Explore how genetic epidemiology maps normal and abnormal genes in populations, identify heritable risks, and use newborn screening to detect metabolic disorders early to prevent fatal outcomes.

Explore how services, social, and spiritual factors affect disease risk, including iatrogenic harms from medical procedures. Learn how beliefs and networks influence health behaviors like alcohol use and smoking.

Explore how epidemiology uses an ecological perspective to view drugs, vaccines, programs, interventions, and policies as systems interacting with their external environment and disease patterns.

Assess how public health solutions can unintentionally create new problems, analyze public health and environmental effects, and guide policies and resource use to reduce harm.

Explore how vaccination creates herd immunity that protects individuals and communities. Discover how higher immunity thresholds reduce transmission and may eradicate disease, with examples from diphtheria, smallpox, and poliomyelitis.

Explore diphtheria as a case study of a toxin-producing bacteria, waning adult immunity in Russia, outbreaks, and the need for adult booster vaccines.

Trace the history of smallpox, a highly contagious and often fatal disease, and how cowpox vaccination led to global eradication by 1980.

Understand how poliomyelitis spreads via the fecal-oral route and can cause paralysis. Utilize IPV and OPV vaccines, boosting gut immunity and herd protection, contributing to eradication in thirty six countries.

Explore syphilis, its three stages from primary sores to neuro syphilis, and how stigma and barriers drive untreated infections, herd immunity myths, and the role of penicillin.

The sanitation revolution in 19th century England reduced infant mortality, driving rapid population growth and shaping the demographic gap, while raising debates on population control and family planning.

Explore the paradoxical effect of sanitation on polio epidemiology: improved sanitation reduced early exposure, weakened maternal antibodies, and contributed to late-century epidemics of paralytic polio.

Vector control for African trypanosomiasis can trigger land-use changes, enabling more cattle grazing and risking overgrazing, drought, and famine without accompanying health education.

The Aswan high dam increased electricity and irrigation, but altered aquatic habitats, raising schistosomiasis, malaria, Rift Valley fever, and dengue risk until clean water and sanitation interventions.

Explore how synergism between malnutrition and infection amplifies disease risk, as each factor worsens the other, reducing antibodies and tissue repair in malnourished children.

Explore how antigenic drift and shift drive influenza evolution and vaccine effectiveness. Trace how zoonotic transmissions, globalization, and human-animal interactions reshape outbreak dynamics.

Appreciate the contributions of epidemiologists over the years and explore how their work has shaped the field of epidemiology.

Explore how epidemiologists investigate epidemics and new diseases, from Lyme disease and Legionnaires to AIDS and hantavirus, and learn how surveillance, case tracing, and prevention inform public health.

Medical technologies empower epidemiology with precise laboratory data and sensitive tests to identify disease and distinguish carriers. This reveals the iceberg phenomenon of asymptomatic cases unseen in surface statistics.

Explore how epidemiologists use ongoing surveillance and field trials to evaluate vaccines, monitor safety, and guide polio, smallpox, and measles immunization programs.

Analyze data to inform policies and prioritize disease control, balancing funding, political factors, and education to reflect spread potential, mortality risk, and community cost.

Learn how epidemiology applies to clinical questions to improve diagnosis, therapy, and prognosis, while studying population patterns over time to fix present problems and predict future outcomes.

Develop expert testifying skills in courts of law by sharing epidemiologic knowledge on product hazards, environmental exposures, and medication risks, addressing lawsuits from medical liability to product liability.

Learn how the principles and methods of epidemiology guide planning and evaluating community medical care, define epidemiology, and explore branches, risk factors, and ecological contributions.

Discover the scope of epidemiology and gain a clearer view of what this amazing field covers. Recognize there is much more to learn as you continue this journey.