Salmonella: The underestimated danger

Salmon with homemade mayonnaise, tiramisu, and stuffed chicken: all meals that, along with the almost inevitable weight gain, carry a potential hazard—salmonella infection. Here, we explain exactly what Salmonella is and how dangerous it is.

What is Salmonella?

Salmonella are rod-shaped bacteria from the enterobacteria family and are among the most common pathogens worldwide. Salmonella can cause disease in both humans and animals.

Infectious gastrointestinal inflammation caused by Salmonella is called salmonellosis. In addition to poor hygiene or contaminated drinking water, foods infected with Salmonella can also cause salmonellosis. Therefore, it can also be referred to as a food infection.

More than 2,500 types of Salmonella can be distinguished. The most common diseases in humans caused by Salmonella are vomiting, diarrhoea caused by Salmonella Enteritidis and Salmonella Typhimurium, typhoid fever caused by Salmonella Typhi and paratypes caused by Salmonella Paratyphi.

In Germany, salmonellosis is one of the notifiable diseases. Around 16,000 people contract salmonellosis every year. However, experts estimate the number of unreported cases to be higher.

 

Salmonella – stubborn bacteria

Salmonella survive outside of the human – or animal – body for weeks. They can even be detected in dried faeces for over two and a half years. The bacteria like it warm and humid. Under these conditions, they multiply at breakneck speed.

Heat and sunlight or UV radiation accelerate the death of the pathogens. Freezing does not kill Salmonella, but the bacteria multiply more slowly at temperatures below six degrees Celsius.

foodborne infection

Salmonella is often transmitted through foods of animal origin. The pathogens are found particularly often in the following foods:

• raw or undercooked eggs and egg dishes such as mayonnaise or tiramisu
• raw meat such as pork, chicken or other poultry
• Raw sausage types such as mett
• seafood
• ice cream

The insidious thing about Salmonella is that even with extreme bacterial infestation, the food appears completely normal. You can neither see nor smell nor taste the bacteria.

 

Avoid getting Salmonella from food.

To avoid a salmonella infection, raw chicken meat should be heated to a core temperature of 75 degrees Celsius for at least ten minutes. At 55 degrees Celsius, it takes an hour before the risk of infection with Salmonella is sufficiently reduced.

Foods that contain raw eggs are also risky. What makes raw eggs, in particular, so dangerous is that outside of the cold temperatures of the refrigerator, the Salmonella on the eggshell multiplies rapidly and will not die without heat. In addition, the older the egg, the more porous the shell becomes and the easier it is for Salmonella to get inside it. Therefore, you should only use fresh eggs to prepare dishes with raw eggs, then store them as cold as possible and devour them.

Infection through poor hygiene

Unhygienic storage of food that is too warm or too long, as well as an interrupted cold chain when transporting the food, promote the proliferation of Salmonella. Touching or processing infected food can cause Salmonella to infect other foods, objects, or people.

Human-to-human transmission is possible but rare. A salmonella infection through human contact then occurs via a smear infection: the pathogens from the intestine are passed on to other people via the minor stool residue on the hands of the infected person. Salmonella then gets from the hand into the mouth and triggers an infection.

Risk groups for salmonellosis

The human organism can cope with a certain number of germs. From several 10,000 to 1,000,000 germs, however, the body can no longer fight them – you then noticeably suffer from an infection. The higher the number of bacteria, the more severe the course of the disease.

Infants and children, the elderly and people with weakened immune systems are particularly susceptible to infection. Less than 100 germs can trigger one here. People with reduced gastric acid production are also particularly at risk since, in such cases, more Salmonella can get into the intestine.

 

How dangerous is Salmonella?

Poisoning with Salmonella can cause severe gastrointestinal diseases (gastroenteritis) and typhoid or paratyphoid. Salmonellosis usually manifests itself as severe abdominal pain, diarrhoea, nausea, vomiting and fever and can, in extreme cases, lead to death in children and sick or older adults. However, it can also happen that you do not feel any symptoms despite the infection.

The salmonella pathogens of typhoid and paratyphoid enter the bloodstream via the intestines so that the bacteria infect the whole body. The result is often blood poisoning (sepsis), which can also be fatal.

Important: go to the doctor if you suspect Salmonella

Even if the salmonella infection subsides after about a week in most cases, it is essential to see a doctor. Diarrhoea causes a loss of fluids and minerals that need to be replaced.

A laboratory medical examination of stool samples enables the detection of Salmonella. Stool examinations are also required for follow-up checks – until three samples are pathogens-free. Because even after the symptoms have subsided, you can still be contagious for several weeks.

Salmonellosis in pregnancy

If pregnant women are infected with salmonellosis, there is a risk of premature birth. A severe course of the infection can pose a risk to the health of the baby in general. 

Therefore, medical treatment is also essential in this case.

 

Prevention – 7 tips for protection against Salmonella

The primary way to protect yourself is through good hygiene in the kitchen:

1. Raw meat must be well cooked.
2. Foods like mayonnaise that are made with raw eggs should be avoided entirely.
3. Food that could contain Salmonella should be stored strictly separately from other food.
4. Hands should be washed before and after preparing food.
5. It is advisable to change kitchen towels frequently.
6. Kitchen utensils should be rinsed with hot water after use.
7. Defrosting water from frozen meat must not come into contact with other foods.

If you notice symptoms in yourself or your immediate environment indicating salmonellosis, please contact your family doctor immediately.

Another preventive measure is to vaccinate farm animals such as poultry, cattle and pigs against Salmonella of the serotypes Salmonella Enteritidis and Salmonella Typhimurium. There are also numerous (hygiene) guidelines for keepers of farm animals. Nevertheless, these measures only reduce the risk of salmonella infestation in the animals and cannot completely rule it out.