1. HCT I EPIDEMIOLOGHY

2. Objectives  Understand the various methods of disease transmission  Identify the process epidemiologists use to determine the cause of a disease outbreak  Apply investigative epidemiological skills to interpret data and help protect the public health

3. When disease spreads within a community, public health workers try to understand what is happening. They interview people, study medical records, and—just like detectives—try to make sense of the clues they gather. Then they can inform the public of ways to protect themselves from exposure. Epidemiology is widely considered to be the basic science of public health. Epidemiologists count cases of disease (or injury), consider the distribution of the cases, and define the affected population. If a problem is identified, they use data they collect to try to determine its cause and how it is being transmitted. They also recommend how best to control its spread within the population. JOHN SNOW: PIONEER OF EPIDEMIOLOGY VIDEO JOHN SNOW: PIONEER OF EPIDEMIOLOGY VIDEO

4. What is Public Health How would you get information about events, behaviors, or environmental conditions that affect the public health Mystery Illness in New York City

5.  Why do you think mosquito breeding could be relevant to the investigation? Do you know of any diseases spread by mosquitoes? What environmental factors might affect mosquito populations?  What did investigators know—and not know—about the disease outbreak to this point? In other words, what data did they have to work with?

6. What is Epidemiology-  Epidemiology is the study of diseases as they occur in living things. It focuses on understanding the transmission, spread and control of diseases.  With a partner relate what you saw in the video to the process epidemiologists use in their work: epidemiologists go into outbreak areas, interview people, and gather data. This helps them either form a hypothesis that may explain the outbreak, or prove or disprove a hypothesis they already have. Answer the questions on the next PPT

7.  Whom did New York City public health workers interview when they began their investigation? What questions did they ask?  What did they suspect might be responsible for transmitting disease to the human population? How did they come up with this idea?  What did the investigators do next to test their hypothesis?

8. Read Pages 85-87 starting at prevention and control and take notes. Define: The following on a separate sheet of paper direct contact: indirect contact: airborne transmission: food, water, or blood contamination: vector-borne transmission:

9. consider some of the factors that may bring diseases to a given place : human or animal migration: vacation or business travel: climate change: natural disasters:

10. Mystery Solved! West Nile Virus Answer the following on a separate sheet of paper What evidence led investigators to conclude a mosquito was responsible for transmitting the disease? How did the CDC made its initial diagnosis Why wasn’t everyone convinced the initial diagnosis was correct? What, in the end, convinced the CDC to reconsider its diagnosis?