Salmonella infection in humans

Salmonella infections occur mainly via ingestion of contaminated food. Ingested bacteria are usually killed by the acid in the stomach but when they do survive they can cause enteritis. Certain conditions that reduce the acidity in the stomach predispose to infection (e.g.infants, H2 pr Proton pump inhibitor use and pernicious anemia). It has been predicted that about one million organisms need to be ingested to cause infection.

Infection manifests with fever, loose stools, vomiting, dehydration and cramping pain.

Treatment 

Salmonella enteritis is usually self-limiting and does not need antibiotic therapy. Fluid management and symptoms control are the mainstay of the treatment.

However, antibiotics may be indicated in the following high risk groups:

Infants especially in the first 3 months of life
Elderly
Immunocompromised hosts
Individuals with prosthetic heart valves or joints

Salmonella is sensitive to a variety of antibiotics including fluoroquinolones(ciprofloxacin, ofloxacin, levofloxacin), azithromycin, trimethoprim/sulfamethoxazole(Bactrim/Septran) or amoxicillin.

Carrier state

Carrier state is defined as having positive stool cultures for >12 months. It can occur in 1 in about every 200 patients with salmonella enteritis. The bacteria resides in the biliary tree. Chronic antibiotic therapy (Ampicillin) or surgery is needed.