Investigating Outbreaks of Salmonella Typhimurium Using Case-Control Studies, with a Reference to the One Health Approach

Abstract

An outbreak is defined as the occurrence of disease cases in excess of normal expectancy within a particular area and a given time. Foodborne outbreaks caused by gastrointestinal bacteria such as Salmonella Typhimurium are among the most commonly reported and most extensively investigated. The classic outbreak investigation follows a series of well-defined steps which lead to a faster confirmation of the source and hopefully preventing of further cases. These steps are ideally undertaken using a One Health cross-sectorial collaboration approach involving partners from public health, food safety, and the veterinary and environmental sectors. In order to firmly identify the source of the outbreak, descriptive epidemiology is often combined with more robust evidence from analytical epidemiology such as a case-control study. A case-control study assesses whether a specific exposure is associated with illness, firstly by identifying cases (persons known to have been ill) and controls (persons who have not been ill, used as a reference group), and then retrospectively through interviews determining specific exposures for all persons. This information ultimately leads to the calculation of an odds ratio ( see Note 3 ) which indicates the strength of the association between specific exposures and the outcome (illness or no illness). A well-conducted case-control study may substantiate or form core evidence as to the vehicle of a foodborne outbreak and is often a very important investigation tool, particularly in situations where microbiological proof cannot be obtained.

Comparison of Phenotype and Genotype Virulence and Antimicrobial Factors of Salmonella Typhimurium Isolated from Human Milk

“…Salmonella Typhimurium is frequently connected with outbreaks [ 8 ]. One such outbreak associated with chocolate products occurred in 2022, during which 453 people, mainly children, from 14 European countries, Canada, and the United States fell ill [ 9 ].…”

Phage‐based technologies for highly sensitive luminescent detection of foodborne pathogens and microbial toxins: A review

“…Some advanced detection methods for foodborne pathogens and microbial toxins have been established, such as polymerase chain reaction (PCR), immunoassays, high-performance liquid chromatography, and mass spectrometry (Geetha et al, 2020;Jackson et al, 2019;Muratovic et al, 2015;Singhal et al, 2015;Vale, 2020). These methods can effectively shorten detection time, improve detection accuracy, and support high-throughput analysis (Law et al, 2014). However, these methods still experience challenges while detecting low-abundance pathogens and microbial toxins.…”

“…In severe cases, coma, blood and brain tissue infection, sepsis, and even death can occur (Tawil et al., 2012). Other pathogens, such as Salmonella enteritidis , Campylobacter jejuni , Escherichia coli , Vibrio parahaemolyticus , and Staphylococcus aureus , commonly lead to gastroenteritis, bloody diarrhea, acute liver and/or kidney injury, and even death (Beier et al., 2021; Irenge & Gala, 2012; Kuhn & Ethelberg, 2021; Porcellato et al., 2021). Furthermore, some pathogens can produce biotoxins, that is, bacteriotoxins and mycotoxins, which can be poisonous even at trace levels, such as aflatoxin B1 (Bennett & Klich, 2009).…”