Listeria Monocytogenes Clinical Case Study

DISCUSSION QUESTIONS

Clinical Case Study Discussion Questions

1. What is the most likely causative microorganism in this outbreak?

The most likely causative microorganism in this case is Listeria monocytogenes. This pathogen has been described by Osek, Lachtara and Wieczorek (2022) as “a gram-positive, facultative intracellular rod bacteria...” (413). As the authors further indicate, this pathogen happens to be responsible for a serious infection called listeriosis which is associated with the consumption of food contaminated with the said pathogen.

2. Why is this infection associated with processed meats, but usually not with hamburgers or cuts of meat including pork, beef, or chicken?

According to the Centers for Disease Control and Prevention – CDC (2023), this particular germ can be described as hardy and could be rather challenging to eliminate if it spreads to a food processing facility. Further, according to the CDC (2023), it also thrives and could multiply in cold temperature environments – which specifically means that “unheated deli meat, cold cuts, hot dogs, and fermented or dry sausages” are more likely to be infected than food items exposed to heat (of around 165°F). Thus, owing to the fact that refrigeration does not get rid of this particular pathogen, and given that the pathogen is known to thrive in food preparation surfaces, this infection is largely associated with processed meats.

3. What is the appropriate treatment for this disease?

It is important to note that listeriosis can be potentially dangerous for some categories of people. These are inclusive of, persons with weakened immune systems, people over the age of 65 years, and pregnant women. For this reason, the relevance of ensuring appropriate treatment – especially for the aforementioned categories of people – cannot be overstated. According to Micah (2023), treatment for this disease largely depends on how severe the symptoms and signs are. Whereas persons who are not mentioned in the aforementioned categories and present no (or very mild) symptoms may not be in need of any treatment at all, those in the stated categories and those who present with serious symptoms should be put on antibiotics such as ampicillin.

4. Is this condition communicable? If so, are you required to notify any other individuals?

Listeriosis cannot be transmitted from one person to another. Persons only acquire the infection if they eat food that is contaminated with the Listeria monocytogenes bacteria. However, it is important to note that a pregnant woman can pass the disease to the fetus or to the baby at the time of birth. Thus, although the disease cannot be transmitted from one person to another, when infection is noted, there is need to notify the relevant health agencies so that the relevant interventions can be instituted to limit spread of the pathogen. Measures that could be undertaken by the relevant agencies are inclusive of identifying the source of infected food items, issuance of advisories to the public (i.e. on proper handling of food), etc.

5. After considering the types of people at high risk for the disease, would you suppose the causative organism has a high or low pathogenicity? Explain your answer.

In the present scenario, pathogenicity has got to do with the capacity or ability of Listeria monocytogenes to cause disease. Listeria monocytogenes, as Gelfand, Swamy, and Thompson (2023) point out “is an important bacterial pathogen in immunosuppressed patients, individuals at the extremes of age including neonates and older adults, pregnant women, and, occasionally, previously healthy individuals.” As the authors further indicate, infection with the pathogen amongst this this category of persons clinically manifests itself (principally) as bacteremia and central nervous system invasion. It therefore follows that whilst taking into consideration those in this category, Listeria monocytogenes can be considered to have a high pathogenicity.