Salmonella infection

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at February 24, 2016
StartDiseasesSalmonella infection

Salmonellosis is the name for the infection, usually a foodborne illness caused by the Salmonella bacteria. Every year, an estimated 1.2 million Americans are infected with Salmonella, usually through contaminated food, causing diarrhea, severe stomach cramps, and fever. Though a Salmonella infection will often run its course in about 5 days, for some people it can cause serious complications that require hospitalization.


Definition & Facts

Salmonellosis is a disease of the intestines caused by the bacteria Salmonella, which generally spreads from contaminated food, but may also be contracted by handling infected animals, like lizards, turtles, or geckos. The primary form of food contamination is raw or under-cooked poultry and unpasteurized eggs.

In addition, transmission can come from the poor hygiene habits of already infected individuals, particularly when they use the bathroom without thoroughly washing their hands afterwards. Treatment isn't often necessary with most infections clearing up on their own after a few days, but in the case of severe infections, antibiotics can become necessary. Those at risk of severe complications are the very old and young, and those with compromised immune systems.

Symptoms & Complaints

Signs and symptoms of salmonellosis relate to those of gastroenteritis, centering around the stomach and bowels and include severe cramping and watery diarrhea. In some cases, nausea and vomiting can also occur. Often fever, headaches, chills, and body aches can also be present.

Symptoms can appear several hours to several days after exposure, and the disease often runs its course in about 4-7 days. It is possible to be infected and show very little, milder, or even no symptoms whatsoever. Due to fluid loss from vomiting and diarrhea, dehydration and electrolyte problems can occur.


Salmonellosis is caused by ingesting the Salmonella bacteria, of which there are over 2,500 strains. Transmission can arise from improper food handling and storage, exposure from raw or unprocessed dairy and eggs, and eating under-cooked poultry. In addition, handling amphibians, chickens, and reptiles like turtles, geckos, or frogs and then not adhering to proper hand hygiene is another way of contracting the disease. Finally, being exposed to a person who is currently or recently infected can cause the transmission of the bacteria through the fecal-oral route.

Diagnosis & Tests

The main diagnosis for Salmonella infection is through a stool sample done by a doctor. Since these can take several days to return with a result, often the patient will have cleared up and be on the road to recovery when the actual diagnosis is received.

More often than not, a doctor will ask about risk factors - exposure through an already infected person, handling of raw meat (especially poultry), or ingestion of potentially mishandled food. Given risk factors and the severity of the symptoms, a tentative diagnosis of salmonellosis can be suggested until lab reports come back.

If the diagnosis returns positive, and the infection does not seem to be abating or going away at all, the doctor may prescribe antibiotics designed to help the body eliminate the bacteria completely and quickly. In severe cases, a diagnosis will prompt a hospital stay for administration of fluids and antibiotics to keep the patient stable while they recover.

Treatment & Therapy

Treatment for salmonellosis is primarily bed rest and fluids. Because the disease often resolves on its own with no intervention, the risk of exposing others might deter a patient from going to the doctor to get tested. Outside of extremely bad cases, physicians will not often order tests to diagnose Salmonella infection, as the symptoms are nearly identical to other gastrointestinal infections that also do not require any medical intervention.

Constant fluid intake is key to ensure dangerous fluid balance problems do not arise due to dehydration. In addition, electrolyte problems can be concurrent, and should be addressed through application of liquids designed to replace lost sodium, potassium, and magnesium. Salmonella infection can cause extremely severe diarrhea, so fluid loss is a very real concern, and may require hospitalization to correct.

Prevention & Prophylaxis

Prevention of Salmonella infection is fairly simple, if the patient is diligent about hygiene and food safety. Ensuring thorough hand washing before each and every meal, before and after food preparation, and after any bathroom or diaper-related activity is essential to overall good health.

In addition, foods should be cooked through completely, particularly poultry and eggs, giving care to avoid eating cracked or raw eggs in particular. Avoid completely any cheese or dairy products in general that are unpasteurized or raw, and make sure to promptly refrigerate any leftovers from meals.

When preparing food, take extreme caution to make sure that hands and utensils are washed before coming into contact with prepared foods, particularly those that will not be cooked further. Finally, extreme care needs to be used when handling the contaminated clothing or bedclothes of a person infected with Salmonella bacteria; prompt laundering and sanitizing of cloth and surfaces is essential to kill the bacteria and prevent spread. For young children, extra care needs to be taken to make sure they wash their hands completely after using the bathroom or touching contaminated surfaces.