Salmonellosis is an infection mainly caused by eating food contaminated with a bacteria called salmonella. Infection can also occur as a result of contact with an animal carrying the bacteria, even if the animal is neither sick nor has symptoms. Salmonella mainly causes intestinal diseases in humans. There are several kinds of salmonella.
The most common symptoms of salmonellosis are the following:
- Diarrhea, sometimes accompanied by blood in the feces
- Abdominal cramps
- Vomiting (sometimes)
Symptoms generally appear 6 to 72 hours after eating contaminated food or coming into contact with an animal carrying the bacteria. Symptoms usually last 3 to 7 days.
After symptoms have subsided, salmonella can remain in the intestine for several weeks, and even months. People with salmonella in their intestines are ‘carriers’ of the bacteria. They can still spread the disease even when they no longer have symptoms.
Most people infected heal without antibiotic treatment.
People with diarrhea must drink a lot of fluids to avoid being dehydrated. To know more about this, go to the Hydrating and rehydrating When You Have Gastroenteritis page.
Some people with more severe symptoms may have to be hospitalised and treated with antibiotics.
It can take many weeks for some people’s intestines to function properly again. In rare cases, the infection can lead to more serious consequences such as infection of the blood and, exceptionally, arthritis or meningitis (infection of membranes that surround the brain).
The bacterium that causes salmonellosis lives in the intestines of some humans and animals, including birds.
Salmonellosis is an illness spread in 3 ways:
- Through direct contact of hands with the feces of infected people or animals (poultry, birds, cats, reptiles, etc.). It is important to know that an animal can be infected without having had diarrhea
- Through indirect contact with contaminated people or food:
- By eating food contaminated by an infected person handling foodstuff without first washing their hands with soap and water
- By touching surfaces or objects contaminated with human or animal feces
- Through cross contamination, in other words, from a working surface contaminated with salmonella during preparation of meats or raw foods. For example: cutting fruits and vegetables on a working surface already used to cut raw chicken without cleaning it thoroughly first with soap and water
Foods that may be contaminated with salmonella
Though all foods can be contaminated with salmonella, the following are those most often infected:
- Raw meats (mainly chicken, but also pork and beef)
- Fresh produce (vegetables, fruits, grains) contaminated by animal feces
- Raw or undercooked eggs
- Raw or unpasteurized milk
Here are some tips to prevent salmonellosis:
Practice adequate personal hygiene habits
You can protect yourself from salmonellosis and avoid transmission through simple hygiene measures:
- Wash your hands properly with soap and water:
- After using the toilet
- After changing a baby’s diaper
- After helping a child use the toilet
- Before handling food
- After handling raw eggs, meat and poultry
- Before eating
- After touching an animal or its environment
Practice safe handling and preparation of food
- Wash working surfaces after preparation of each type of food (raw meats, vegetables and fruits, etc.)
- When handling food outdoors, such as when barbecuing for instance:
- Use different utensils and plates for raw and cooked meats
- Clean, with soap and water, serving dishes, cutting boards and utensils between handling of raw and cooked foods
- Make sure that the poultry you eat is completely cooked
- Avoid preparing food or drinks or serving them yourself to other people when you suffer from gastrointestinal symptoms
Follow safe practices for conserving food
- Keep food cool at a temperature not exceeding 4 °C (40 °F)
- Refrigerate or freeze food quickly, including leftovers from a meal
- Thaw food in the refrigerator, in cold water or in the microwave, never at room temperature
- Keep raw meats properly wrapped at the bottom of the refrigerator to prevent blood or fluids from leaking on other food
- Always separate raw meats from fruits, vegetables, cooked food and ready-to-eat products
For further information on habits to take when handling and storing foods, see the Guide du consommateur de l'épicerie à la maison (in French only) on the ministère de l'Agriculture, des Pêcheries et de l'Alimentation du Québec (MAPAQ) website.
People at risk
The disease can affect the entire population. However, it can affect most severely:
- Young children
- Pregnant women
- People with health problems
Consumption of food being recalled for salmonella
A recall is a warning published about a food when the consumption of it is considered to be dangerous to health. If you have eaten food that is subject to a recall and show symptoms in the 3 days that follow, contact Info-Santé 811 or your doctor.
To know the list of recalled foods, visit the websites of the ministère de l’Agriculture, des Pêcheries et de l’Alimentation du Québec (MAPAQ) (in French only) or the Canadian Food Inspection Agency .
Salmonellosis is a reportable disease in Québec. When a laboratory test reveals the presence of salmonella in a specimen from an infected person, the laboratory must inform public health authorities in their region.
Last update: September 13, 2018