HLTH 485
CASE STUDY ASSIGNMENT INSTRUCTIONS
OVERVIEW
In order to master epidemiological concepts acquired in this course, it is imperative that you
understand how disease outbreak investigations work. You will be able to navigate a real-life
outbreak and solve important questions in relation to the case.
INSTRUCTIONS
You will find the case study titled: “Case Study I: Snow on Cholera” in the appendix I section in
the back of the textbook. Read the case study and answer all the questions below. You must use
complete sentences.
A: Observations on cholera
1. Concerning John Barnes, how was cholera communicated? What were the modes of
disease transmission? What is the correct epidemiological term for the modes of
transmission that were identified?
John Barnes contracted cholera through his infected sister. Her infected clothing was sent
to Barnes without being washed and he contracted cholera upon opening the box and
handling the clothing. Fomite transmission was involved in the actual transfer.
2. How long is a fortnight? Two Weeks
3. In the examples or circumstances presented, what were the various modes of transmission
stated or at least alluded to? Which were correct? Which were incorrect and why? What
role did personal hygiene and sanitation (including food preparation and hand washing)
play in the transmission of the disease and continuation of an outbreak? Primary mode of
transmission was person-to-person contact. Effluvia given off from a sick person was
also mentioned as a mode of transmission. Snow hypothesized that affection began first
with the alimentary canal. Thus, personal hygiene and sanitation played a role in
transmission because people were in contact with infected individuals and did not wash
their hands properly. When they prepared or ate food, cholera was transmitted to the
stomach and bowels. Bed linens that hosted cholera "evacuations" also were a mode of
transmission. Infected water was seen as a transmitter.
Page 1 of 9
, HLTH 485
4. Several instances of causal association were presented or alluded to in the examples
presented in the case. List the various instances of association you can identify from the
examples or situations presented in the case. What role did social class, poverty, and
housing arrangements play in association? What role did water play in association?
Association was found in the following cases: food infected by those who had cholera;
water infected by feces or cholera evacuations that was then used for cooking and
drinking; involuntary passage of evacuations from infected individuals; poverty was
found to be a major risk-factor for the spread of disease because poor people lived in
cramped conditions where cooking and eating took place in the same room as the sick
person; and lack of sanitary conditions including hand washing.
Page 2 of 9
CASE STUDY ASSIGNMENT INSTRUCTIONS
OVERVIEW
In order to master epidemiological concepts acquired in this course, it is imperative that you
understand how disease outbreak investigations work. You will be able to navigate a real-life
outbreak and solve important questions in relation to the case.
INSTRUCTIONS
You will find the case study titled: “Case Study I: Snow on Cholera” in the appendix I section in
the back of the textbook. Read the case study and answer all the questions below. You must use
complete sentences.
A: Observations on cholera
1. Concerning John Barnes, how was cholera communicated? What were the modes of
disease transmission? What is the correct epidemiological term for the modes of
transmission that were identified?
John Barnes contracted cholera through his infected sister. Her infected clothing was sent
to Barnes without being washed and he contracted cholera upon opening the box and
handling the clothing. Fomite transmission was involved in the actual transfer.
2. How long is a fortnight? Two Weeks
3. In the examples or circumstances presented, what were the various modes of transmission
stated or at least alluded to? Which were correct? Which were incorrect and why? What
role did personal hygiene and sanitation (including food preparation and hand washing)
play in the transmission of the disease and continuation of an outbreak? Primary mode of
transmission was person-to-person contact. Effluvia given off from a sick person was
also mentioned as a mode of transmission. Snow hypothesized that affection began first
with the alimentary canal. Thus, personal hygiene and sanitation played a role in
transmission because people were in contact with infected individuals and did not wash
their hands properly. When they prepared or ate food, cholera was transmitted to the
stomach and bowels. Bed linens that hosted cholera "evacuations" also were a mode of
transmission. Infected water was seen as a transmitter.
Page 1 of 9
, HLTH 485
4. Several instances of causal association were presented or alluded to in the examples
presented in the case. List the various instances of association you can identify from the
examples or situations presented in the case. What role did social class, poverty, and
housing arrangements play in association? What role did water play in association?
Association was found in the following cases: food infected by those who had cholera;
water infected by feces or cholera evacuations that was then used for cooking and
drinking; involuntary passage of evacuations from infected individuals; poverty was
found to be a major risk-factor for the spread of disease because poor people lived in
cramped conditions where cooking and eating took place in the same room as the sick
person; and lack of sanitary conditions including hand washing.
Page 2 of 9
