1 / 22

Principles of Epidemiology

Principles of Epidemiology. www.doh.state.fl.us. Studying Disease. Pathology Study of disease Epidemiology Study of the frequency and distribution of disease Epidemiologist – “disease detective” Work to prevent, control, and eradicate diseases.

tallys
Download Presentation

Principles of Epidemiology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Principles of Epidemiology www.doh.state.fl.us

  2. Studying Disease • Pathology • Study of disease • Epidemiology • Study of the frequency and distribution of disease • Epidemiologist – “disease detective” • Work to prevent, control, and eradicate diseases

  3. What does an epidemiologist have to consider in today’s world when studying human disease?

  4. Do you speak my language?(Or rather the epidemiologist’s language)

  5. Endemic Diseases • Diseases that are always present in a population of a particular geographic region • Examples (in U.S.): • Tuberculosis • Chickenpox • Influenza • Mumps • Plague (not in human populations)

  6. Epidemic Diseases • An unusually large number of disease cases in a population in a particular region • Usually occur within a relatively short period of a time • Ex. Influenza • Ex. Ebola virus in Africa

  7. Zoonotic Diseases • Infectious diseases that humans acquire from animal sources • Ex. Ebola virus • Ex. Plague (Yersinia pestis) Chimpanzee – ebola virus host. www.primates.com Prairie Dogs – carriers of plague. www.nps.gov

  8. Legionnaire’s Disease - Epidemic • Type of bacterial pneumonia (Legionella pneumophila) • First described in 1976 after an outbreak during an American Legion convention in Philadelphia • How did this happen?

  9. Sporadic Disease • A disease that occurs only occasionally within a population of a particular geographic region. • Ex. Tetanus, plague, botulism, cholera

  10. Disease Transmission • Communicable Disease • Disease that is transmitted from human to human. • Noncommunicable Disease • Diseases that are nontransmissible. • Ex. Botulism from ingestion of tainted food • Contagious Disease • A communicable disease that is easily transmitted from person to person. • Ex. Influenza

  11. Terms Concerned With the Rate of Disease • Incidence Rate • # of new cases in a specific time period in a given population • Prevalence Rate • # of total existing cases in a population • Morbidity Rate • # of new cases of a particular disease that occurred during a specified time period per a specifically defined population • Mortality Rate • Fraction of people who die from a disease

  12. Pandemic Disease • A disease that occurs in epidemic proportions in many countries or sometimes worldwide. • Examples: • HIV/AIDS • Tuberculosis • Malaria

  13. Factors Affecting Infection • Characteristics of the: • Pathogen • Host • Environment

  14. Factors Concerning the Pathogen • Virulence of pathogen • How pathogen enters body • Number of organisms that enter the body

  15. Factors Concerning the Host • Health of individual • Nutrition of individual • Behavior of individual

  16. Factors Concerning the Environment • Characteristics of geographic location • A sufficient reservoir for pathogens and appropriate carriers of a disease • Sanitary conditions • Access to drinkable water

  17. Chain of Infection www.thorstenconsulting.com www.ericmstrauss.com safetydrs.blogspot.com

  18. Reservoirs of Infection • Any site where a pathogen can multiply and survive until it is transferred to a host. • Living Reservoirs • Animal/Human carriers • Nonliving Reservoirs • Air, soil, dust, food, milk, water, fomites

  19. Types of Carriers • Passive Carrier • Carry pathogen without ever having had disease • Incubatory Carrier • Able to transmit pathogen during incubation period • Convalescent Carrier • Transmit a pathogen while recovering from a disease • Active Carrier • Recovered from a disease but continue to carry pathogen indefinitely

  20. Modes of Transmission • Direct Contact • Skin-to-skin contact • Mucous membrane-to-mucous membrane contact • Indirect Contact • Airborne droplets that contain respiratory secretions from sneezing or coughing • Food and water contaminated by fecal material. • Arthropod vectors (ticks, fleas, lice, mosquitoes, flies, mites) • From fomites • Transfusion of contaminated blood or blood products

  21. Public Health Agencies • World Health Organization (WHO) • Centers for Disease Control and Prevention (CDC)

  22. The End

More Related