ANSWER
1. Do you believe that these occurrences of gastrointestinal disease indicate a community outbreak? Week 6 Epidemiology Case Study Questions 1. Why not?
Yes, there is probably an outbreak based on these incidents. When the prevalence of a disease in a certain neighborhood or group is higher than anticipated, an epidemic takes place. An outbreak would be declared if the number of reported cases was higher than the local baseline rate for gastrointestinal disease.
2. How does Hepatitis A spread? Which infectious sources should public health authorities concentrate on?
Transmission: The fecal-oral route is how hepatitis A is spread, usually through tainted food or water or intimate contact with an infected individual.
Sources of Infection: Contaminated food sources should be the main concern of public health professionals.
contaminated food workers.
sources of water.
inadequate hygiene and sanitation standards.
3. What informational resources are currently available to help identify if other members of the community have Hepatitis A?
records from the local health department.
Admission records from clinics and hospitals.
Reports on laboratory testing.
Syndromic surveillance systems keep an eye on symptoms related to the gastrointestinal tract.
4. a. Examine the outbreak’s descriptive epidemiology, taking into account the epidemic curve (Figure 1).
In order to determine the outbreak’s peak and the incubation period, the epidemic curve probably displays the number of cases over time.
The curve’s shape will determine how it is interpreted:
A point-source epidemic is indicated by a single peak.
Several peaks indicate ongoing or spread exposure.
b. Did the patients’ symptoms match those of Hepatitis A?
Indeed, Hepatitis A. c. symptoms include fatigue, nausea, vomiting, jaundice, and stomach pain. Did the outbreak seem to be over, and what was its likely trajectory?
If the number of cases rose quickly before declining, the outbreak most likely followed a point-source pattern. The absence of new cases for a duration longer than the maximum incubation period of Hepatitis A (up to 50 days) determines whether it is over.
5. What research or analysis might you do to support the theory that the outbreak was caused by tainted food?
A case-control investigation Examine the exposure histories of the controls (healthy people) and cases (sick people).
Determine which foods are frequently consumed by cases as part of a trace-back study.
Environmental assessment: Look for hygienic infractions or tainted food items at food preparation locations.
Laboratory analysis: Check for the Hepatitis A virus in food and stool samples.
6. How will you sample your prospective individuals for the survey? Explain your response.
Purposive sampling is the method used, with an emphasis on people who have eaten at the accused restaurant or have consumed the suspected food.
Rationale: This guarantees that the sample is pertinent to determining the origin of the outbreak.
7. How would you gather data for the survey from chosen households?
Techniques:
To record food consumption history, use surveys or structured interviews.
For quick data collecting, use technological technologies such as online surveys.
Gather stool samples for analysis at a lab.
8. What are the reasons for the illness of 20% of those who were not directly exposed to the polluted source?
secondary transmission by intimate contact with an infected person.
cross-contamination of surfaces or other food items.
incorrect exposure history categorization.
9. In this situation, how would you define your case?
A case can be characterized as: “Any individual with acute onset of gastrointestinal symptoms (e.g., jaundice, nausea, vomiting, abdominal pain) who ate at [specific restaurant] between [timeframe] and has laboratory confirmation of Hepatitis A or epidemiological linkage to a confirmed case.”
10. Write the case’s alternative hypothesis and null hypothesis.
Null Hypothesis (H₀): The tainted food has nothing to do with the Hepatitis A outbreak.
Alternative Hypothesis (H₁): The Hepatitis A outbreak is linked to the tainted food.
11. Determine the Odds Ratio (OR) from Figure 2 and describe what it means.
OR computation: depends on the information in Figure 2 (a 2×2 table is needed).
Interpretation: An OR > 1 indicates a link between sickness and exposure to the probable source.
12. List a few variables that might cause the number of instances reported to rise.
enhanced reporting and surveillance infrastructure.
raised awareness among the general public and healthcare professionals.
delayed onset of symptoms that results in case identification in retrospect.
13. In this case, what kind of variable is contaminated food?
It is the assumed cause of the outbreak, making it an independent variable.
14. What kind of graph is shown in Figure 1?
Most likely a histogram or epidemic curve.
15. In this situation, what function do inferential statistics serve?
Establishing correlations between variables (such as food exposure and disease) and assessing the statistical significance of observed patterns are made easier with the use of inferential statistics.
16. The ____________ variable is the total number of patrons who dined at the restaurant.
variable that is discrete.
17. What benefits might descriptive statistics offer that the graph might not?
In order to gain a deeper understanding of the data, descriptive statistics offer measurements of central tendency (like the mean incubation period) and variability (like the range of symptom onset).
18. How leadership should foster a workplace that encourages health and reduces foodborne illness.
applying stringent hygienic measures.
ensuring frequent food safety training for employees.
encouraging an environment of open communication and accountability.
19. Hand hygiene public health initiatives are one example of a population-based intervention to stop foodborne outbreaks.
enforcing restaurant food safety regulations.
Hepatitis A vaccination campaigns in high-risk regions.
20. How foodborne outbreaks are decreased through data use:
Targeted interventions are made possible by the prompt detection of trends in reported cases.
Cases are mapped geographically to identify the contaminating source.
Agencies that share data are better able to respond quickly to outbreaks.
Citations
CDC stands for Centers for Disease Control and Prevention. (2021). Health Professionals’ Questions & Answers about Hepatitis A. https://www.cdc.gov/hepatitis/hav/index.htm was retrieved.
WHO, the World Health Organization (2020). food-related illnesses. Foodborne Diseases (https://www.who.int/news-room/fact-sheets/detail)
M. E. Mayorga et al. (2020). the study of foodborne illness epidemiology. Gastroenterology: Current Opinion, 36(1), 33–38. 10.1097/MOG.0000000000000601 https://doi.org
QUESTION
Week 6 Epidemiology Case Study Questions
1. Do you think these cases of gastrointestinal illness represent an outbreak in the community? Why or why not? (1 point)
2. How is Hepatitis A transmitted? On what sources of infection should public health
officials focus? (2 points)
3. What existing sources of information might help determine if others in the community
have Hepatitis A? (2 pts)
4. a. Interpret the descriptive epidemiology of the outbreak including the epidemic curve
(Figure 1) (3 points)
b. Were symptoms among patients consistent with Hepatitis A?
c. What was the likely course of the outbreak and did it appear to be over?
5. What studies or investigations might you undertake to confirm the hypothesis that contaminated food was the source of the outbreak? (3 points)
6. What will be your sampling approach for the survey of potential subjects? Justify your answer. (2 points)
7. How would you collect information from selected households for the survey? (2 points)
8. If 20% of persons not directly exposed to the contaminated source became ill, and if the contaminated food supply was the source of the outbreak, what explanations exist for these persons becoming ill? (2 points)
9. What will be your case definition in this scenario? (2 points)
10. Write the Null and Alternative hypothesis for this case (2 points)
11. From figure 2, calculate the Odd Ratio (OR) and explain what it represents (2 points)
12. Name some of the factors that could lead to an increase in the reported number of cases. (2 points).
13. Contaminated food in this scenario is what type of variable? (1 pt)
14. Looking at figure 1, what type of graph is this? (1 pt)
15. What role does inferential statistics play in this scenario? (2 pts)
16. Total number of the people who ate at the restaurant is______________variable. (1 pt)
17. Graphs such as figure 1 help researchers to visualize data, what value will descriptive statistics add that the graph may not provide? (2 pts)
18. Explain briefly how leadership might create a work environment that promotes well-being, personal health, and self-care, and reflect how this would mitigate work -related hazards such as food poisoning outbreak. (2 pts)
19. Offer some population-based interventions that might be used to prevent foodborne outbreaks. (3 points).
20. Describe how the use of data would lead to the reduction of foodborne outbreaks with regards to quick identification of the site and source of illness. (3 pts)