Chapter Four: Epidemiology
Practical Application: Book Activity
Practical Application
Setting the Scene
Legionnaires’ disease is a type of pneumonia caused by the Legionella bacteria. In nature, Legionella live in nature and rarely cause illness. In a man made setting, Legionella can grow if water is not properly maintained. These man made water sources become a health problem when small droplets of water that contain the bacteria get into the air and people breathe them in (CDC, 2022b).
Legionnaires’ Disease is a national reportable condition. In 2015, the New York City Department of Health and Mental Hygiene (NYC DOHMH) detected an abnormal number of Legionnaires’ cases in the South Bronx via the notifiable conditions public health policy. To better understand how and why this was occurring, the response team within the Department of Health collected more data, including the sampling of many cooling towers within the designated areas within NYC in search of the Legionella pneumophilia bacteria. Using the surveillance data and information about the disease, such as where bacteria are commonly found, the health department was able to identify the source (environment) as a cooling tower in the city. Locating this tower led to the destruction of the bacteria within the tower and a new local law to test for Legionella as part of the required certification and maintenance inspections (Chamberlain, et al. 2017).
Think About It.
- Imagine you were a nurse during this outbreak.
- How might you have been involved in the outbreak?
- What steps would you take if a patient came in with Legionnaires’ Disease?
- Imagine you were a part of the NYC DOHMH when this outbreak took place.
- What questions would you ask when the abnormal number of cases first arose?
- How would you answer these questions? What data would you need to collect?
- What were the three corners/vertices of the Epidemiologic Triangle for this outbreak?
- Why might Legionnaires disease be classified as a notifiable condition?
- Classify the following diseases as epidemic, pandemic, or cluster. Describe why you selected each classification.
- Malaria in Africa, which is present at all times because of the presence of infected mosquitoes.
- Ebola in parts of Africa where it exceeds what is expected for this region.
- COVID-19
- Measles, as occurring among employees at Factory X in Fort Worth, Texas in March 1981
Practical Application: Additional Guidance
Exercise Title
Epidemiology in Community/Population Care
Objective
This exercise aims to engage nursing students in understanding the functions of epidemiology in the process of community diagnosis and health surveillance, in the formulation of objectives and targets.
Preparing for the Exercise
- Introduction: Introduce the Legionnaires’ outbreak in New York City in 2015. It could be helpful to also provide additional information to students, including
- Presentation slides or handouts on Legionnaires’ disease (including information on Legione