[7] Most commonly, salmonellosis cases arise from salmonella bacteria from animals,[8] and chicken is a major source for these infections.

[10][11][12] Both vegetarian and non-vegetarian populations are susceptible to Salmonella infections due to the consumption of contaminated meat and milk.

At the hospital, the patient may receive fluids intravenously to treat the dehydration, and may be given medications to provide symptomatic relief, such as fever reduction.

In severe cases, the Salmonella infection may spread from the intestines to the blood stream, and then to other body sites, and can cause death, unless the person is treated promptly with antibiotics.

[citation needed] Those whose only symptom is diarrhea usually completely recover, but their bowel habits may not return to normal for several months.

Endotoxins first act on the vascular and nervous apparatus, resulting in increased permeability and decreased tone of the vessels, upset thermal regulation, vomiting, and diarrhea.

[22] Salmonella bacteria can survive for some time without a host; they are frequently found in polluted water, with contamination from the excrement of carrier animals being particularly important.

The Malawian researchers identified an antibody that protects children against bacterial infections of the blood caused by nontyphoidal Salmonella.

A study at Queen Elizabeth Hospital in Blantyre found that children up to two years old develop antibodies that aid in killing the bacteria.

A similar approach was considered in the United States, but the Food and Drug Administration decided not to mandate vaccination of hens.

[44] Salmonellosis annually causes, per CDC estimation, about 1.35 million illnesses, 26,500 hospitalizations, and 420 deaths in the United States every year.

[45] About 142,000 people in the United States are infected each year with Salmonella Enteritidis specifically from chicken eggs, and about 30 die.

In 1998, the USDA moved to close plants if salmonella was found in excess of 20 percent, which was the industry's average at the time, for three consecutive tests.

After several DNA analyses seemed to point to a specific Belgian strain, the "Joint ECDC/E FSA Rapid Risk Assessment" report detected turkey production as the source of infection.

[citation needed] In March 2007, around 150 people were diagnosed with salmonellosis after eating tainted food at a governor's reception in Krasnoyarsk, Russia.

[citation needed] In Singapore about 150 people fell sick after eating Salmonella-tainted chocolate cake produced by a major bakery chain in December 2007.

[56] Both salmonellosis and the microorganism genus Salmonella derive their names from a modern Latin coining after Daniel E. Salmon (1850–1914), an American veterinary surgeon.

Bacteriophages have a number of advantages over other alternatives: (i) high efficacy in killing bacteria, (ii) minimal or no side effects, (iii) no allergic effects, (iv) production is rapid and inexpensive, and (v) they are host-specific and therefore do not affect the intestinal microbiota or other saprophytic bacteria in the environmental milieu.

In the specific case of poultry, good results have been obtained by reducing the infection of Salmonella, E. coli and Campylobacter.

[60] Bacteriophages are suitable to prevent or reduce the colonization of pathogenic bacteria and therefore diseases in cattle,[61] where phages are supplied either individually or in cocktail to farm animals, the routes and methods of application were examined by various authors and the application of phages through oral tube feeding or feed intake showed a reduction of pathogenic bacteria without affecting the intestinal microbiota of the host.

From an immunological point of view Salmonellosis is an infection caused by gram-negative bacteria infiltrating epithelial cells of the small intestine in the distal ileum whereby inducing acute inflammatory response called enteritis.

This happens because lymphatic vessels are responsible for draining fluids, cells, and microbes from the intestinal tissues and carrying them to these lymph nodes.

Once in the mesenteric lymph nodes, Salmonella can then enter the bloodstream, leading to a systemic infection that spreads throughout the body.

It enables Salmonella to effectively invade neighboring cells by injecting bacterial proteins directly into them, facilitating its spread and evasion of the host's immune defenses.

Moreover, these cells are essential for producing IFN-γ in the intestinal mucosa, which is crucial for controlling Salmonella Typhimurium through an IFN-γ-dependent mechanism.

[69] Recruited monocytes are specifically adapted to regulating bacterial replication through the production of antimicrobial molecules (anti-microbial factors such as iNOS, TNF-α and IL-1β), however, they exhibit limited capability as antigen-presenting cells.

[70] While monocytes help in containing the bacteria initially, the inability to effectively present antigens can delay or weaken the activation of T cells, which are necessary for a strong and specific immune response.

Recruitment of these cells to follicles plays a crucial role in initiating early T-cells mediated responses to Salmonella infection.

[79] These findings strongly suggest that CD4+-mediated protection is facilitated by the contribution of CD8+ cytotoxic T cells in the immune response against Salmonella.

However, when serum transfer was employed, the observed response indicated the crucial antibody-dependent role in secondary Salmonella infections.