QUESTION 11 During an outbreak of varicella 250 school child

QUESTION 11

During an outbreak of varicella, 250 school children were investigated.

Of these, 125 met the case definition. Of the children who did not get sick, 80% were vaccinated for varicella. Of the children that were sick, 10% were vaccinated.

Construct a 2x2 table in the following manner. Use the chart to answer the following question:

The value of the most appropriate measure of association (Relative Risk or Odds Ratio) is:

Sick

Not Sick

Total

Vaccinated (exposed)

Total vaccinated

Not Vaccinated

(not exposed)

Total not vaccinated

Total

Total sick

Total not sick

0.444

0.028

0.375

0.128

0.5 points

QUESTION 12

You are following a group of people with occupations requiring them to work primarily outdoors to determine if their exposure to ticks, mosquitoes, and other insects increases their likelihood of contracting a vector borne disease.

What type of study is it?

Ecological

Cross Sectional

Case Control

Cohort Study

Experimental

0.5 points

QUESTION 13

Outbreaks of the Ebola virus infection have occurred since 1976. Ebola has high infectivity and mortality in humans.

Ebola epizootic has also been devastating to other animals and caused large number of deaths, in thousands and caused devastation in which of these animal population?

Domestic Cats

Fish

Giraffes

Gorillas

Zebras

Lions

0.25 points

QUESTION 14

Consider a cohort of 5 initially disease-free subjects being studied over a 5 year period as follows:

Subject 1: Joins at the start of the study, remains disease free for 5 years

Subject 2: Joins at the start of the study, develops disease after 3 years

Subject 3: Joins at year 3, remains disease free for 2 years

Subject 4: Joins at year 2, develops disease after 1 year

Subject 5: Joins at the start of the study, lost to follow-up after 2 years

The total person-years contributed by those at risk for the outcome, for this study is:

points

QUESTION 15

A hospital in rural Maine noted that there were 32 reported infections associated with 1,596 surgeries performed last year. The hospital reported 4012 discharges last year.

The most appropriate measure of these hospital associated infections would be:

Risk adjusted infection rate

Crude infection rate

Adjusted infection rate

The number of infections reported. i.e. 32

0.5 points

QUESTION 16

The following 2x2 table is constructed for a cohort study of 460 people in a village for the risk of contracting malaria using bed nets.

Use the table to answer the following question:

Which is the most appropriate measure of association to use in this situation is Relative Risk or Odds Ratio?

Write your response in the space provided.

Maleria

No Malaria

Total

Use bed nets

264

276

Do not use bed nets

184

Total

106

354

460

0.5 points

QUESTION 17

Cumulative incidence refers to new cases that develop among initially disease-free individuals in a certain time period and allows for the unequal weightage of the study participants.

True

False

0.5 points

QUESTION 18

An example of a disease transmitted by fomites is:

Lyme Disease

Cholera

Dengue

Malaria

0.5 points

QUESTION 19

A disease that has been eradicated worldwide is:

Trichuriasis

Rabies

Smallpox

Schistosomiasis

Lymphatic filariasis

0.5 points

QUESTION 20

In contrast to analytical study designs, descriptive study designs collect individual level data and compare the occurrence of disease with exposure.

True

False

0.5 points

QUESTION 21

During an outbreak of varicella, 250 school children were investigated.

Of these, 125 met the case definition. Of the children who did not get sick, 80% were vaccinated for varicella. Of the children that were sick, 10% were vaccinated.

Construct a 2x2 table in the following manner. Use the chart to answer the following question:

What is the value of “P”?

Sick

Not Sick

Total

Vaccinated (exposed)

Total vaccinated

Not Vaccinated

(not exposed)

Total not vaccinated

Total

Total sick