Around the world, Salmonella is one of the main causes of diarrhea. Other common symptoms of a Salmonella infection include abdominal cramps and vomiting.
Most people with Salmonella infections have mild symptoms and recover without treatment. However, some require care in a hospital setting.
People often develop this type of infection after coming into contact withcontaminated food or water.
In 2019, 13 people from eight states became sick after eating ground beef that contained a strain of Salmonella. The Centers for Disease Control and Prevention (CDC) issued a safety alert but declared the outbreak over by the end of the year.
Pet reptiles and amphibians can also transmit Salmonella. In 2017, an outbreak linked to pet turtles affected at least 76 people in 19 states, according to the CDC.
Salmonella is a type of bacteria that can cause diarrheal illness in humans.
There are over 2,500 subtypes, including animal and human strains. Some are present in animals but can also affect humans. Fewer than 100 strains of Salmonella bacteria are likely to infect people.
In the United States, Salmonella is a major cause of bacterial infection. According to the CDC, it causes around 1.35 million infections, leading to 26,500 hospitalizations and 420 deaths, every year.
Symptoms usually appear between 6 hours and 6 days after the initial infection and last 4–7 days, according to the CDC.
- stomach cramps and abdominal pain
- a sudden fever
- vomiting, in some cases
Some strains of Salmonella can infect the urine, blood, bones, joints, and the nervous system, including the spinal fluid and brain. Severe complications can result.
Salmonella bacteria live in the intestines of birds, animals, and humans. Most infections in humans develop after eating food or drinking water that has been contaminated by feces.
Uncooked meat, seafood, and poultry
Contamination can occur during processing. For example, harvesting seafood in contaminated waters is a common cause of Salmonella infection.
Also, the infection can spread if a person handles contaminated raw meat, then touches other food without washing their hands.
Eggs from a bird with a Salmonella infection can contain the bacteria.
The Food and Drug Administration (FDA) estimate that every year, 79,000 cases of foodborne illness occur in the U.S. due to eggs containing Salmonella.
Cooking the eggs can reduce the risk. However, some popular sauces, such as mayonnaise, can contain raw eggs.
Fruits and vegetables
Watering fruit or vegetable plants with contaminated water, or washing the produce in this water, can lead to Salmonella infection.
Lack of hygiene
Contamination and infection can occur if people do not keep kitchen surfaces clean and do not wash their hands during food preparation, after using the bathroom, and after changing a baby’s diapers.
When a person has the bacteria on their hands, they can spread it by touching other people or by touching frequently used objects and surfaces.
Pet reptiles or amphibians
Most reptiles and amphibians carry Salmonella in their guts without becoming ill. They shed the bacteria in their droppings.
The bacteria can then quickly spread to their skin and anything that they come into contact with, including cages, toys, clothes, furniture, and household surfaces.
People should not keep pet reptiles indoors if there are children under 5 years of age, pregnant women, older people, or people with weakened immune systems in the household.
Since 1975, the FDA have banned the sale and distribution of small turtles because of the risk of Salmonella infection.
Salmonella infections are more common in summer than in winter.
Overall, people with the highest risks of infection are:
- older people
- people with weakened immune systems
- pregnant women
Because of the risk of infection, caregivers should not allow young children to handle reptiles or chicks and young birds.
If a woman develops a Salmonella infection during pregnancy, there can be additional risks. Dehydration and a lack of nutrients that result from the infection can harm the mother and baby.
In around 4% of Salmonella infections during pregnancy, the bacteria spread to the blood. This can lead to intrauterine sepsis, a potentially life threatening condition.
A doctor will ask about:
- other ongoing health issues
- changes in the diet or food preparation habits
- contact with pets
- recent travel
Diarrhea and vomiting are usually a clear sign of gastroenteritis. Blood and stool tests can help determine the cause of the infection.
Symptoms of Salmonella-induced gastroenteritis usually disappear without treatment after 4–7 days.
Treatments may include:
- fluids to prevent dehydration.
- antimotility drugs to reduce cramping and stop diarrhea
- antibiotics for severe symptoms or if bacteria have entered the bloodstream or are likely to do so
Good hygiene is key to preventing Salmonella infection. Here are some tips:
People should regularly wash their hands with soap and warm water or use hand sanitizer. This is especially important:
- before preparing or eating food
- after using the bathroom
- after changing a baby’s diapers
- after touching pets and other animals
- after gardening
When dealing with food:
- Keep cooked and raw foods separate.
- Store raw foods in a fridge on the shelves below ready-to-eat foods.
- Wash raw fruits and vegetables thoroughly before eating them.
- Cook foods thoroughly, especially meats and eggs.
- Keep cooking utensils and work surfaces clean.
- Regularly replace used dishcloths with clean ones.
- Avoid drinking untreated water, for example, from streams, rivers, and lakes.
Salmonella can live for varying amounts of time in different foods. For example, in 2015, researchers found that the bacteria can live in cookie and cracker sandwich snacks for at least 6 months.
When buying eggs, make sure that they come from a supplier who keeps them refrigerated.
At home, it is important to store eggs at a temperature no higher than 40°F (4°C). Throw away any cracked or dirty eggs.
The FDA require any boxes of eggs that have not been treated for Salmonella by pasteurization to carry this warning:
“Safe handling instructions: To prevent illness from bacteria, keep eggs refrigerated, cook eggs until yolks are firm, and cook foods containing eggs thoroughly.”
The FDA provide further detailed advice about storing and cooking eggs.
Pet reptiles or amphibians should not live inside the house if there are older people, pregnant women, very young children, or people with weakened immune systems in the household.
Preventing the spread of infection
If anyone in a household develops Salmonella infection:
- wash clothes, bedding, and towels in the washing machine at the hottest setting possible
- thoroughly clean toilet seats, toilet bowls, and all bathroom handles, basins, and taps with detergent and hot water, followed by a household disinfectant regularly
The CDC recommend seeing a doctor if any of the following occur:
- diarrhea, vomiting, or both persisting for at least 2 days
- symptoms of dehydration, such as dark urine, dizziness, reduced urination, and dry mouth
- a fever above 102˚F (39˚C)
- blood in stool
If a child has any of the following, they should receive medical care:
- diarrhea that lasts more than 1 day
- vomiting that lasts at least 12 hours
- signs of dehydration, including no urination for at least 3 hours or a dry mouth or tongue
- blood in stool
- a fever above 102˚F (39˚C)
Older people, pregnant women, and people with weakened immune systems should not hesitate to seek medical advice.
Salmonella is a type of bacteria that commonly causes diarrhea.
People often develop Salmonella infection after coming into contact with pet reptiles or contaminated water or food. It is crucial to ensure that all foods are stored and cooked properly.
Symptoms of the infection usually go away without treatment. However, if a person has a high risk of complications or if symptoms persist, the person should receive medical care.