Disease Detectives

Epidemiologist

Person who specializes in epidemiology

Epidemiology

Branch of medical science concerned with the incidence, distribution, and control of diseases that are prevalent among a population at a special time and are produced by some special causes not generally present in the affected locality.

Environmental Causes of Health Problems

Smoking, air pollution, flooding and drought, extreme heat, UV exposure, pesticides, chemical spills, lead contamination, water pollutants, heavy metals, ventilation pollutants, noise induced hearing loss, waste and toxic substance, food contamination, and other pathogenic agents as prions

Outbreak

(localized epidemic) - more cases of a particular disease than expected in a given area or among a specialized group of people over a particular period of time.

Epidemic

large numbers of people over a wide geographic area affected

Pandemic

An epidemic occurring over a very wide area (several countries or continents) and usually affecting a large proportion of the population.

Cluster

an aggregation of cases over a particular period esp. cancer & birth defects closely grouped in time and space regardless of whether the number is more than the expected number

Public Health Surveillance

the systematic collection, analysis, interpretation, and dissemination of health data to gain knowledge of the pattern of disease occurrence in order to control and prevent disease in the community.

Step 1

Prepare for Field Work

-Research, supplies, and equipment

-Administrative arrangements

-Local Contacts

Step 2

Establish the Existence of an Outbreak

-expected # of cases for an area

-other factors in play

Step 3

Verify the Diagnosis

-proper diagnosis

-not lab error

-commonality

Step 4

Define and Identify Cases

-case definition

Case Definition

a. Clinical information - about the disease or condition

b. Characteristics - of the affected people

c. Location or place - as specific as possible as restaurant, county, or several specific areas

d. Time sequence - specific time during which the outbreak or condition occurred

Step 5

Describe and Orient Data in terms of Time, Place and Person Triad

Agent

A microbial organism with the ability to cause disease.

Chain of Infection

An AGENT leaves a RESERVOIR through a PORTAL OF EXIT, and is conveyed by some MODE OF TRANSMISSION, and enters the appropriate PORTAL OF ENTRY to infect a susceptible HOST.

Step 6

Develop Hypothesis (Agent/Host/Environment Triad) = Chain of Transmission

• The triad consists of an external agent, a susceptible host, and an environment that brings the host and agent together.

Infectious Groups

viruses, bacteria, protistans (protozoa), fungi, animals (worms)

Step 7

Evaluate Hypothesis

-Observational Studies: how and why

-Cohort: based on exposure status

-Case-Control: works backward from effect or illness

Cohort Study

retrospective: starts at exposure in past and moves forward to outcome

prospective: starts at present exposure and moves forward to the outcome

Step 8

Refine Hypothesis and do Additional Studies

-verify no confirmation then look for other modes of transmission

Step 9

Implement Control and Preventative Measures

Step 10

Communicate Findings