Epidemiology and Biostatistics Week 1 – Chapter 1 “Epidemiology” Copyright Kaplan University 2009

Review of quick Seminar guidelines  Archive will be available after class  Use “???” before questions so that I know you have a question  Participate!!!

Epidemiology…  Study of something that affects a population  Study of factors that determine the occurrence & distribution of disease in a population  One of the ways in which disease, injury and clinical practice are studied

Classical Vs. Clinical  Classical Population oriented studies of the community origins of health problems. Population oriented studies of the community origins of health problems.  Clinical Use of research designs and statistical tools to study patient in health care setting

Other Types of Epidemiology  Chronic Disease Epidemiology Sampling and statistical analysis Sampling and statistical analysis Diabetes Diabetes  Infectious Disease Epidemiology Laboratory support Laboratory support HIV/AIDS HIV/AIDS  Syndromic Epidemiology Patterns of symptoms and signs as they relate to bioterrorism Patterns of symptoms and signs as they relate to bioterrorism

Diseases  Natural History of Disease: Also known as the natural “progression” of a disease Also known as the natural “progression” of a disease  Intervention Against Disease: Therapeutic Example: Chemotherapy, radiation, surgical intervention Preventative Example: Anti-smoking public service message

Disease Profile  History of Disease: Family history of breast cancer Family history of breast cancer  Intervention: Therapeutic: mastectomy, radiation, chemotherapy Preventive: Mammography on a regular basis

Stages of Disease  Pre-disease Stage: No disease present  Primary Prevention: Prevention of disease from starting  Latent Stage: Asymptomatic; disease is in progress  Secondary Prevention: Treatment prevents progression  Symptomatic Stage: Manifestation of disease  Tertiary Prevention: Slowing of disease; preventing further damage

Challenge Time !!! # 1  A group of 20 male college students volunteer/consent to have their PSA levels checked three times yearly (every 4 months) for the four years they are in college as part of a study by University Hospital on prostate cancer. Is this study considered to be: A. Clinical Epidemiology B. Classical Epidemiology

# 2  If an epidemiologist is sent out to investigate suspected food poisoning at a church picnic after reports of 20 people becoming ill with symptoms of vomiting/diarrhea occurring three hours after the picnic ended, he is practicing: A. Infectious disease epidemiology B. Syndromic epidemiology C. Classical epidemiology D. Clinical epidemiology E. Both b and c F. Both a and d

# 3  The natural progression of a disease is also known as: A. Preventive intervention B. Pre-disease staging C. Natural History of Disease D. None of the Above

# 4  The susceptibility of an immuno- compromised individual to common colds and other illnesses is a: A. Environmental Factor B. Disease Factor C. Host Factor D. Conditional Factor

# 5  Within the stages of disease, which of the following stages may be defined by manifestation of disease symptoms? A. Secondary Prevention B. Symptomatic Stage C. Pre-disease Stage D. Latent Stage

So What Causes a Disease?  Biological Mechanisms?  Social Causes?  Environmental Causes? The answer is: Social factors and environmental factors can contribute to the biological mechanism which triggers a disease

Circumstances Contributing to Disease Manifestations  Host Factors: Ability to adapt to the stresses that are produced by an agent  Agent of Disease/illness (3): Biological Agents (allergens, organisms, toxins, and food) Biological Agents (allergens, organisms, toxins, and food) Chemical Agents (chemical toxins and dust) Chemical Agents (chemical toxins and dust) Physical Agents (Kinetically propelled energy such as bullets, cars, and blunt trauma) Physical Agents (Kinetically propelled energy such as bullets, cars, and blunt trauma)

Manifestations (continued)  Environmental: May effect the probability and circumstances of contact between host and agents. Examples include: Examples include: SanitationSanitation Road ConditionsRoad Conditions OvercrowdingOvercrowding Poor EconomicsPoor Economics

VECTORS  Defined: Insects, arthropods and animals which aid in the spread of disease by themselves being a host capable of transmitting disease causing organisms to the host they are living on Insects, arthropods and animals which aid in the spread of disease by themselves being a host capable of transmitting disease causing organisms to the host they are living on  Examples: Mosquitoes = West Nile Virus Tick = Lyme Disease Rats = Bubonic Plague Mosquitoes = Canine Heartworm Snail = Haemonchus contortus (nematode)

Epidemiological Triad Host Agent Environment For disease propagation to exist, only one of these three factors must be disrupted Vector

Risk Factors for Diseases  B iological/Behavioral  E nvironmental  I mmunological  N utritional  G enetics  S ervices, Social, Spiritual

Any Questions ?