The outbreaks of infectious diseases present unwanted events that occur due to a combination of factors related to the environment, the affected populations, and causative agents. The so-called epidemiologic triad is among the tools used to study disease outbreaks in a detailed way. This method focuses on the relationships between three factors, without which epidemics are impossible. This essay applies the model to foodborne salmonellosis, one of the most frequent contagious diseases affecting millions of people every year.
The first component of the model of disease outbreaks is the etiologic agent. This term is used to define a range of harmful microorganisms and their toxins that lead to the development of infectious diseases. In relation to foodborne salmonella, this infectious disease is caused by non-typhoidal or Typhimurium Salmonella (Brown et al., 2017). According to Brown et al. (2017), non-typhoidal Salmonella is among the most frequent causes of foodborne infections in the U.S., causing at least a million new cases every year. As for the distinctive features of these bacteria, it is important to note that various serotypes of Salmonella are quite hardy, which means that they do not always need a host organism to survive (Brown et al., 2017). The etiologic agent causes various changes in host organisms, varying from mild to life-threatening symptoms.
In epidemiology research, the host factors are understood as the traits or characteristics of living organisms that make them more vulnerable to some diseases. In the case of foodborne salmonellosis outbreaks, the potential host factors can be divided into two groups. To begin with, people’s risks to get this infection are related to some habits and unhealthy behaviors that can be stopped or changed. Among them are poor food processing practices, lack of proper hand hygiene, and similar factors (Appling, Lee, & Hedberg, 2019). Apart from the presence of preventable mistakes, there are host factors that do not depend upon the host’s behaviors and food choices. Thus, for instance, the risks of the infection are increased for people in some age groups due to the peculiarities of their immune system. This group of host factors includes the age under five, being a person of advanced age, the history of immune system disorders, the diagnosis of AIDS or malaria, and the extensive use of antibiotics and antimicrobial drugs prior to exposure to Salmonella (Appling et al., 2019; Brown et al., 2017). Therefore, the factors associated with the risks of getting sick are drastically different in terms of their preventability.
As for the final component of the triad, the environmental factors, they involve external conditions that facilitate the survival of the etiologic agent. In relation to foodborne salmonellosis, the disease affects people since they consume many products of animal origin. These bacteria easily survive in the gastrointestinal tract of different farm animals and birds, which leads to the contamination of various products such as meat, eggs, and milk (Appling et al., 2019). However, if fruits and vegetables contact with the feces of animals carrying the bacteria, they can also become the source of infection (Appling et al., 2019). Without the host organism, the etiologic agent can live in small ponds for months (Appling et al., 2019).
In summary, the outbreaks of foodborne salmonellosis are caused by different subspecies of Salmonella that easily survive in different environmental conditions and contaminate a range of products of animal origin, as well as agricultural products. The host factors include some preventable behaviors such as improper hand hygiene and mistakes in product processing. Other factors influencing the occurrence of this disease are presented by age, the history of problems with the immune system, and drug overuse.
References
Appling, X. S., Lee, P., & Hedberg, C. W. (2019). Understanding the relation between establishment food safety management and Salmonella risk factor violations cited during routine inspections. Journal of Food Protection, 82(2), 339-343.
Brown, A. C., Grass, J. E., Richardson, L. C., Nisler, A. L., Bicknese, A. S., & Gould, L. H. (2017). Antimicrobial resistance in Salmonella that caused foodborne disease outbreaks: United States, 2003–2012. Epidemiology & Infection, 145(4), 766-774.