Disease Detectives

Vector

Vector

A quantity that has magnitude and direction

Cluster

An aggregation of cases over a particular

period of time.

Morbidity

The rate of incidence of a disease.

Bias

Surveillance is an example of this.

Agent

a person who acts or does business for another

Incubation period

The time that lapses between infection and

the first appearances of the symptoms of

the disease.

Mortality

The measure of the frequency of death.

Virulence

Severity of disease in a host.

Epidemiology

The study of patterns, causes, effects, and

disease conditions in a population.

Infectivity

The capacity to cause infection in a host.

Parasite

An organism that depends on another

organism.

Risk

The probability that one will become infected by an illness or injury within a specific period of time.

Pathogenicity

Capacity of a host to cause disease.

Surveillance

The systematic collection, analysis, and

interpretation of data.

Pandemic

Occurrence of a phenomenon over several

countries and geographic locale with a

large population affected.

Prevalence

Proportion of the host population infected

at a given time.

Pathogenicity

Capacity to cause disease in a host.

Incidence

The rate at which new cases of infection

arise in a population.

Outbreak

More cases of a particular disease than

expected in a given area, at a given time.

Zoonosis

An infectious disease that is transmissible from animals to humans.

Fomite

A hairbrush carrying lice would be an

example of this.

Reservoir

Soil is an example of this.

1. Prepare for field work, 2. Establish the existence of an outbreak, 3. Verify the diagnosis, 4. Define and identify the cases, 5. Describe in terms of time, place and person, 6. Develop a hypothesis, 7. Evaluate the hypothesis, 8. Refine hypothesis, 9. Implement control and prevention measures, 10. Communicate findings

Name the ten steps to an outbreak investigation.

Environment, Host, Agent or Time, Person, Place

What are the three components of the

epidemiological triad?

Biological - bacteria, viruses

Nutritional - lack of nutrition, excess nutrition (obesity)

Chemical - poison, alcohol

Physical - radiation, trauma

Provide two examples of the following

agents: (ANSWERS MAY VARY)

Biological -

Nutritional -

Chemical -

Physical -

Epicurve

What do epidemiologists call a graph like the one below?

1. Point

2. Common continuous

3. Propagated

Name the three types of this graph that one can potentially visualize. Write them next to

the graphs below.

1. Strength of association, 2. Consistency, 3. Specificity, 4. Alternative explanations, 4. Temporality, 5. Dose-response relationship, 6. Biological plausibility, 7. Experimental evidence, 8. Coherence

List all of Hill's Criteria of Causation.

agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host.

Present a the Chain of Infection.

•Influenza: VIRAL

•Aspergillus: FUNGAL

•Gonorrhea: BACTERIAL

•Ascaris: PARASITIC

•Tuberculosis: BACTERIAL

•Toxic Shock Syndrome: BACTERIAL

•Genital Warts: VIRAL

•Strongyloides: PARASITIC

•Chagas disease: PARASITIC

•Cholera: BACTERIAL

Understanding the biological underpinnings of diseases is important. Determine

whether the following diseases are bacterial, viral, fungal, or parasitic in origin. Write the

origin next to each disease.

•Influenza:

•Aspergillus:

•Gonorrhea:

•Ascaris:

•Tuberculosis:

•Toxic Shock Syndrome:

•Genital Warts:

•Strongyloides:

•Chagas disease:

•Cholera:

In 2009, a community survey of people who went on the Zipper at the Syosset Carnival for blood pressure was conducted in which residents were asked how many times they had their blood pressure tested in the past year. The answers from the first 20 participants

are listed below. In 2014, they did the same thing.

2009: 0, 2, 0, 0, 24, 1, 2, 0, 2, 2, 1, 1, 0, 0, 5, 1, 360, 10, 2, 3

2014: 2, 1, 0, 0, 2, 1, 4, 3, 2, 1, 0, 4, 2, 52, 1, 9, 2, 7, 4, 5

Organize the data into a table of frequency distribution. Find the mean, median, and mode of the data set. You must set the columns for the distribution yourself.

a.) Systematic deviation of results or inferences

b.) Surveillance, Selection

c.) Widen the study base by contacting people at other

locations, including (but not limited to) hospitals,

preschools, elementary schools, and middle schools,

various businesses and workplaces, and senior homes.

An epidemiologist decides to investigate the effects of a severe heat wave that occurred at Chicago from July 10, 2011 to July 20, 2011, during which temperatures

often exceeded 40°C. To do this, he visits 10 public and private high schools located in Chicago and 20 others scattered around the state of Illinois. Each student fills out a survey asking them about their living conditions and experiences during those 10 days, any preexisting health conditions, and any changes in health during or following the heat wave.

a.) Define bias

b.) What is one type of bias identified in this study?

c.) How can this study be altered to change its bias?

Selection bias: occurs when study subjects are selected for the study as a result of a third unmeasured variable which is association with both the exposure and the

outcome.

Explain what study the epidemiologists are utilizing:

1. Epidemiologists identify a population that is exposed to a suspected carcinogen and a non-exposed population and track them to determine who develops leukemia.

Recall bias: In a case control study, patients do not remember exposures that they do not believe caused the disease as well as those they believe did cause it (cases) and they don't recall some exposures as clearly as cases (controls)

Explain what study the epidemiologists are utilizing: Switzerland is determine to have a higher breast cancer incidence and a higher consumption of dietary fat when compared with other countries.

Information bias: Occurs from systematic error in the assessment of a variable

Explain what study the epidemiologists are utilizing: Epidemiologists are interested in the possible relationship involving increased serum cholesterol level (exposure) to electrocardiographic (ECG) evidence of CHD (the disease). They survey a population; for each participant they determine the serum cholesterol level and perform an ECG subsequently for evidence of CHD.

True

Infectious disease are more likely to be distributed to others in a larger population: (2 pts.)

True or False

d. The exposed and non-exposed groups under study be as similar as possible with regard to possible confounding factors

In cohort studies of the role of a suspected factor in the etiology of a disease, it is essential that:

a. There be an equal number of persons in both study groups

b. At the beginning of the study, those with the disease and those without the disease have equal risks of having the factor