Salmonellosis

Salmonellosis is a symptomatic bacterial infection caused by members of the genus Salmonella, gram-negative, motile, nonsporulating, facultatively anaerobic bacilli of the family Enterobacteriaceae first identified in 1884 ^[3]. The genus includes Salmonella enterica—with numerous subspecies and more than 2,500 characterized serovars—and Salmonella bongori, and subgroups and serovars can differ substantially in pathogenic potential ^[2][4]. Clinically distinct presentations include nontyphoidal Salmonella gastroenteritis (a self-limiting diarrheal illness) and enteric (typhoid or paratyphoid) fever caused by the human-restricted serovars Typhi and Paratyphi ^[3][4].

Nontyphoidal salmonellosis typically produces diarrhea, fever, abdominal cramps, and vomiting beginning 12–36 hours after exposure and lasting two to seven days, with occasional progression to dehydration; severe cases may involve bloodstream invasion and sepsis, although sepsis is uncommon ^[1][4]. Symptoms can range from mild to severe, and the very young, older adults, and immunocompromised individuals are more likely to develop serious disease ^[1][4]. Enteric fever caused by Salmonella Typhi and Paratyphi is a potentially life-threatening acute febrile systemic infection diagnosed by isolating the pathogen in culture, and treatment options have narrowed with the emergence of extensively drug-resistant S. Typhi.

Salmonella is a leading global cause of acute bacterial gastroenteritis, with the greatest human disease burden attributed to consumption of animal-derived products, particularly poultry, pork, beef, and fish, as well as some non-animal foods such as fruits and vegetables ^[1][2]. In the United States, CDC estimates place annual salmonellosis at approximately 1.35 million illnesses, 26,500 hospitalizations, and 420 deaths, with about 142,000 egg-associated Salmonella Enteritidis infections each year; Salmonella-related mortality from 1990 to 2006 was highest among older adults and immunocompromised persons ^[4]. Reported European examples include a 2012 Salmonella Thompson outbreak traced to smoked salmon that caused over 1,060 infections and four deaths, predominantly in the Netherlands, and a multi-country S. Stanley outbreak in the same year ^[4]. The continued emergence of multidrug-resistant and extensively drug-resistant strains is an increasing public-health concern ^[1][2].

Salmonella is transmitted along the farm-to-fork continuum, most commonly through consumption of contaminated foods of animal origin—especially poultry, eggs, pork, beef, and fish—as well as contaminated water and, less frequently, non-animal foods such as fruits and vegetables ^[1][2][3]. Direct contact with infected persons or animals is an additional route of spread ^[3]. Person-to-person and foodborne outbreaks have been linked to specific products, such as smoked salmon implicated in a Northern European S. Thompson outbreak in 2012 ^[4].

Salmonellosis control relies on two complementary strategies: reducing Salmonella prevalence in animals through herd-health, biosecurity, and food-chain measures, and protecting humans from exposure along the farm-to-fork continuum ^[1]. A One Health framework spanning farm, manufacturing, distribution, retail, and consumer levels is recommended, with emphasis on proper food handling, prevention of cross-contamination, thorough cooking, and safe water ^[1][2]. For enteric fever specifically, vaccination of at-risk persons, improved sanitation, promotion of food hygiene, and detection and management of chronic carriers are essential preventive measures ^[3].

1. 1 Galán-Relaño Á et al. Salmonella and Salmonellosis: An Update on Public Health Implications and Control Strategies. Animals (Basel). 2023 Nov 27. PMID: 38067017. doi: 10.3390/ani13233666. PubMed: https://pubmed.ncbi.nlm.nih.gov/38067017/
2. 2 Lamichhane B et al. Salmonellosis: An Overview of Epidemiology, Pathogenesis, and Innovative Approaches to Mitigate the Antimicrobial Resistant Infections. Antibiotics (Basel). 2024 Jan 13. PMID: 38247636. doi: 10.3390/antibiotics13010076. PubMed: https://pubmed.ncbi.nlm.nih.gov/38247636/
3. 3 Qamar FN et al. Salmonellosis Including Enteric Fever. Pediatr Clin North Am. 2022 Feb. PMID: 34794677. doi: 10.1016/j.pcl.2021.09.007. PubMed: https://pubmed.ncbi.nlm.nih.gov/34794677/
4. 4 Wikipedia contributors. Salmonellosis - Wikipedia [Internet]. Wikipedia. cited 3 Sept 2026. Available from: https://en.wikipedia.org/wiki/Salmonellosis
5. 5 Shih HP et al. Anti-interferon-γ autoantibody-associated immunodeficiency. Curr Opin Immunol. 2021 Oct. PMID: 34175547. doi: 10.1016/j.coi.2021.05.007. PubMed: https://pubmed.ncbi.nlm.nih.gov/34175547/