Reference no: EM133463231
Case Study: Outbreak in a Neonatal Intensive Care
Instructions
For the purposes of this exercise, you will be asked to work in groups to participate in a healthcare associated infection investigation. Information regarding the scenario will be provided to you in parts, each of which will be followed by related discussion questions. Choose one group member to read each segment of information aloud to the rest of the group. After receiving the information, work as a team to formulate answers to each discussion question.
Learning Objectives
- Describe infection control practices in a healthcare setting
- Calculate disease prevalence, case-fatality rate, and odds ratio
- Create a histogram of cases over time
- Choose an appropriate epidemiological study design, given information about an outbreak
- Interpret epidemiologic study results
1. Which of the following describe contact precautions to prevent the spread of infection in a hospital setting?
a. Limiting patient movement
b. Providing gown and gloves for patient
c. Using dedicated equipment
d. Cleaning and disinfecting patient room daily
e. All of the above are contact precautions
f. A, B, and D only
2. Prevalence is:
a. number of deaths in infected persons total number of infected persons
b. number or cases (new and existing) population at risk of infection
c. number or cases (new and existing) total number of infected persons
d. none of the above
3. True or False: In a case control-study, the controls should represent the population that gave rise to the case patients.
1. What pertinent information would be helpful for you and the physician to know regarding this patient?
2. What infectious agents would be of greatest concern to the physician?
3. Could the mother be the source of infection, why or why not?
4. What might be other sources of infection in this patient?
5. Would you consider this a hospital acquired infection? Discuss what factors would lead you to determine if an infection is hospital acquired.
6. What steps should the infection control practitioner take to ensure the infection does not spread to other patients?
7. Considering the information given, does it warrant a full investigation into the source of the infection?
8. Aside from an outbreak of disease, what might be other explanations of a rise in reportable diseases? Are these explanations likely for the observed causes of P. aeruginosa?
9. What is the prevalence of P. aeruginosa infections in patients who visited the NICU more than 2 days? Prevalence is a proportion that measures disease in a given population that is considered to be at risk. Prevalence is found by dividing the number of infected persons by the total number of people in the population at risk:
Prevalence = number or cases (new and existing)
population at risk of infection
10. Calculate the case-fatality rate of infected patients from the NICU since January of the previous year. Case-fatality rate is the proportion of deaths in infected persons among the total number of infected persons (Note: Despite its name, a case fatality rate is not a true rate, but simply a proportion).
Case-fatality rate = number of deaths in infected persons
total number of infected persons
11. Construct a histogram plotting the number of cases, by type of infection, for each month of diagnosis beginning with January 2014 and ending in March 2015. (Hint: Plot Blood and ETT on the same graph, differentiated by shading).
12. Look at the histogram you created. Is this histogram an epidemic curve? Why or why not?
13. What are the next steps in determining the source of the outbreak?
14. Considering that all cases are on mechanical ventilators and a large number of patients had bacterial colonization on endotracheal tubes, what control measures, if any do you implement?
15. Given this information what type of epidemiologic study design would you use?
16. You decide to conduct a case-control investigation. Discuss what criteria should be used to classify cases and controls.
17. The odds ratio for contact with an infected nurse was 1.21, with a 95% confidence interval of 0.35 - 4.65. Do these results imply that contact with an infected nurse was a risk factor for developing P. aeruginosa infection? Why or why not?
18. From table 2 above, calculate the odds of acquiring infection if you had contact with the infected, long-nailed nurse within this study. The odds of acquiring infection from an infected nurse is found by dividing the number of cases who had contact with the nurse by the number of controls having contact with the nurse.
19. Using the same table, calculate the odds of acquiring infection if you did not have contact with the long-nailed infected nurse. The odds of being a case if you did not have contact with the long-nailed infected nurse is found by dividing the number of cases who did not have contact with the nurse by the number of controls who did not have contact with the nurse.
20. Calculate the disease odds ratio using the data provided. A disease odds ratio is found by obtaining the ratio of the probability of being a case among the exposed and the probability of being a case among the non-exposed. These two probabilities have been found in questions 18 and 19, and were 0.54 and 0.083.