Conditions Salmonellosis

Salmonellosis is a gastrointestinal disease caused by bacteria of the genus Salmonella. The bacteria can multiply on food and are usually ingested when these foods are eaten. 

In Germany, this foodborne infection occurs primarily after consuming dishes containing raw eggs or raw meat that have not been heated sufficiently. This typically causes diarrhea. Salmonellosis should be treated with antibiotics only in certain cases. This applies if there are signs that the infection is spreading through the body, and for certain high-risk groups. 

Salmonellosis causes acute intestinal inflammation. This typically results in sudden-onset diarrhea. There may also be a mild fever, headache and abdominal pain, discomfort and, sometimes, vomiting. The symptoms can last for several days and then usually subside on their own.

If severe diarrhea persists for a long time, significant loss of fluid (dehydration) can occur. Important salts are also lost in the process. This further impacts a person’s general condition. In infants, young children, and the elderly, severe fluid and salt loss can cause significant strain on the person’s circulation and become life-threatening. 

In rare cases, the infection spreads from the intestine to other organs and can be accompanied by a high fever (septic course).

A salmonella infection is caused by bacteria of the genus Salmonella. Salmonellosis is one of the classic foodborne infections. It is different from typhoid and paratyphoid that are caused by other types of Salmonella bacteria and are usually accompanied by fever and severe illness. Both of these illnesses are rare in Germany and are usually contracted during travel.

In most cases, the pathogens causing salmonellosis enter the body through foods contaminated with the pathogen. However, they can also be spread from person to person or from animal to human.

Infection through food containing eggs

The Salmonella species Salmonella Enteritidis is widespread in Germany. It is transmitted primarily through raw or insufficiently heated eggs, or food containing eggs.

Infection through meat

The Salmonella species Salmonella Typhimurium is also common in Germany. It is primarily transmitted through raw meat or meat products that have not been heated or have not been heated sufficiently, such as minced meat or “Mettwurst” meat paste.

Infections caused by other foods 

Plant foods can also contain Salmonella. For example, herbal tea, mung bean sprouts, and melons have been previously identified as sources of infection. Chocolate and smoked eel are other rare sources of infection in Germany.

Infection from person to person

Infection from person to person can occur through a smear infection, especially if hygiene is inadequate. Infection can also occur via contaminated surfaces. However, this route of transmission is very rare.

Infection from animal to human

Infections through direct contact with domestic animals are rare. Salmonella transmission via the animals’ feces can occur, particularly when keeping reptiles. Surfaces contaminated with feces can also be a source of infection.

In most people, symptoms last a few days. For certain risk groups, however, salmonellosis can sometimes be dangerous, for example, if it leads to severe fluid and salt loss or if the bacteria spread into the body beyond the intestine. This can lead to longer and more severe courses of the disease.

The following groups are at an increased risk of a severe infection: 

• infants
• older persons
• people with pre-existing conditions 

It is also possible that taking antacid medications increases the risk of contracting the disease. However, the data on this is not clear.

Salmonella infections are common worldwide. Illnesses occur as sporadic cases, clusters of cases, such as in families, or as larger outbreaks. In 2019, there were 277 outbreaks in Germany, with 1,101 people affected. A total of 13,693 cases were reported in Germany in 2019. Due to the measures taken to prevent the spread of COVID-19 between 2020 and 2022, the figures from those years are of limited value.

There were 15,274 reported cases of salmonella poisoning in Germany in 2024. This figure is similar to those recorded in the years before the COVID pandemic. Many infections occur in late summer. Children under 5 years of age are most frequently affected. Deaths resulting from a Salmonella infection are rare in Germany. 

Mandatory vaccination was introduced in Germany in 2008 for laying hens, broilers, and turkeys. Since then, the number of human infections with Salmonella enteritidis has significantly declined.

After a person becomes infected, symptoms usually appear within 12 to 36 hours (known as the incubation period). Typically, the disease progresses without complications.  

Mild cases

Salmonellosis begins as an acute intestinal inflammation with the symptoms of a gastrointestinal infection. The symptoms subside on their own within 4 to 10 days.

Severe form 

In rare cases, Salmonella infection can spread to other organs. 

Possible symptoms include:

• inflammation of the joints
• gall bladder inflammation
• inflammation of the innermost layer of the heart (endocardium) and heart valves
• meningitis
• pericarditis
• pneumonia
• skin infections
• inflammation of the renal pelvis and kidneys

If severe, salmonellosis should be treated with antibacterial drugs (antibiotics). Treatment in hospital is sometimes necessary.

Fewer than one in 1,000 people die from salmonellosis. Those most at risk are the elderly and people with weakened immune systems.

Salmonella multiplies in a temperature range between 10 and 47 degrees Celsius, and in some cases as low as 6 to 8 degrees Celsius. It can survive for several months in its surroundings and in various foods.

Food handling 

The following measures will reduce the risk of Salmonella infection:

• Salmonella can be reliably killed at temperatures above 70 degrees Celsius with a minimum cooking time of 10 minutes.
• Raw meat and sausage products, poultry, seafood, eggs, creams, salads, and mayonnaises with raw egg should be stored in the refrigerator. Ice-cream should be put in the freezer immediately after purchase.
• The cooling time should be kept short for precooked foods. Hot foods should be consumed within 2 hours of the last time they were heated.
• When thawing frozen poultry and game, the water produced often contains Salmonella. It should therefore be collected separately and disposed of immediately. All items that came into contact with it should be thoroughly cleaned with hot water afterwards.
• When meals are heated up in the microwave, a sufficient cooking time is essential to ensuring that the food is fully heated. 
• Baby food should be prepared with water at a temperature of at least 70 degrees Celsius, then allowed to cool quickly and consumed as soon as possible, but no later than within 2 hours.

The Bundesinstitut für Risikobewertung (BfR) (Federal Institute for Risk Assessment) has compiled further information on protection against foodborne infections in private households.

Hygiene when cooking

• Wash hands thoroughly with soap after contact with food potentially containing Salmonella.
• Meat should always be prepared using kitchen utensils that haven’t been used for vegetables or salad. Clean the kitchen utensils thoroughly before further use. 
• Change kitchen towels frequently and wash them at a minimum temperature of 60 degrees Celsius.

Prevention in kindergartens, schools, and homes

The most important precaution is hand washing. This is especially true after using the toilet, after contact with suspected infectious items such as diapers. Handwashing is also always essential before preparing meals and following contact with foods such as poultry. 

Avoiding infection by affected persons

• Sick persons with symptoms are usually not able to work and should stay home.
• Sick children under 6 years of age should not visit community facilities such as daycare centers and schools. Once recovered, they must be symptom-free for 2 days before returning. Parents must inform community facilities of their child’s illness. 
• Special rules apply to certain food establishments or community food service facilities. Persons suspected of having salmonellosis, who are ill, or who are excreting (“shedding”) Salmonella are temporarily prohibited from working in these locations.

Further information on what to do in the event of a salmonella infection is provided in various languages by the Federal Institute for Public Health (BIÖG) on the website infektionsschutz.de.

It is not usually necessary to determine the cause of a gastrointestinal infection. Detection of the precise pathogen responsible is only required in certain cases. Diagnostic identification of pathogens is required, for example, in severe cases, in people with certain pre-existing illnesses or those who work with food. It is also useful to detect the pathogen if several people become ill and an outbreak is suspected.

If salmonellosis is suspected, the following specimens may be tested:

• stool
• anal swab
• vomit
• suspicious food
• blood (in severe cases)

All detected cases of salmonella infection must be reported to the local health authority.

Treatment of salmonellosis depends on the progression and severity of the infection.

Treatment of a mild infection

Salmonellosis usually clears up without treatment provided that it is confined to the gastrointestinal tract. However, it is important to compensate for the loss of fluids and salt that it causes. For this reason, it’s important to drink plenty of fluids. Electrolyte solutions, available from pharmacies, can also be beneficial. In uncomplicated cases, antibiotic therapy is usually not administered, as they have no effect on the course of the disease, but can prolong bacterial shedding and therefore the potential for transmission.

Treatment of a severe infection

Severe cases require treatment with antibiotics. This applies, for example, to signs that the pathogens are spreading beyond the intestines into the body, such as fever. This treatment helps prevent the spread to other organs.

To avoid complications, antibiotics may be used in high-risk groups, even in cases with a mild course. 

These high-risk groups include:   

• babies in the first year of life
• older persons
• persons with congenital or acquired immunodeficiency
• patients with known damage to the heart valves or blood vessels.