Salmonella infection in children

What is Salmonella?

Salmonella is the name given to a family of many different types of bacteria. These bacteria are named after the American veterinarian who first discovered them, Daniel Salmon.

How can you get infected with Salmonella?

The most common way to get Salmonella is by consuming food products contaminated with the bacteria. Salmonella reaches these food products through infected animals — eggs, chicken, undercooked meat, dairy products — or from fresh produce washed with contaminated water, etc. A less common method of transmission is through direct contact with an infected animal. Salmonella can be found not only in chicken but also in reptiles such as turtles, iguanas, and more. It is also possible to become infected through contact with the stool of an infected person. As a result, transmission within families is quite common.

How infectious is Salmonella?

In infectious diseases, there is a term known as “inoculum,” which describes the quantity of a pathogen (usually a virus or bacteria) needed to cause disease. For Salmonella, an inoculum of about 1,000,000 bacteria must be consumed for illness to occur.

Why is this important? In contrast to other infectious organisms — for which the inoculum can be much lower (as few as 10 organisms) — Salmonella requires a much larger quantity to cause disease. In other words, that same Kinder Egg would need to contain around a million Salmonella bacteria for the consumer to get sick.

What kind of symptoms does a Salmonella illness cause?

It depends on the age and general health of the person infected. In most healthy individuals, symptoms range from asymptomatic illness (no symptoms at all) to temporary diarrhea. Gastrointestinal symptoms usually begin within two days after exposure. These symptoms include abdominal pain, diarrhea (which may or may not be bloody), nausea, and vomiting. Sometimes, fever and chills may also occur. In healthy individuals, the fever typically resolves within two to three days, and diarrhea resolves within a few days to one week.

I recommend reading the key chapter about diarrhea in children on my website here, where you can learn about the different types of diarrhea — including watery, bloody, and mucosal — and view related images.

It’s important to note that most people who get infected with Salmonella continue to carry the bacteria in their intestines for a short time and may shed it in their stool for about 5–7 weeks after the infection. This asymptomatic carriage does not require further workup or treatment. In people with certain medical conditions (especially those who are immunosuppressed), younger infants, and the elderly, the illness can be significantly more severe and dangerous, as you’ll see later in this chapter.

So, is getting infected with Salmonella dangerous?

As mentioned earlier, most Salmonella infections in healthy individuals cause diarrhea that resolves on its own. In some cases, the illness can last longer and may require hospitalization for fluids and supportive care.

Rarely — in up to 5% of known cases (and possibly more, since many asymptomatic cases go undiagnosed) — the infection can enter the bloodstream from the intestines and spread to various organs or blood vessels.

Such complications occur mostly in patients with specific risk factors, which we will discuss below.

Is there a vaccine against Salmonella?

As noted earlier, there are several types of Salmonella.

There is a vaccine against *Salmonella Typhi* (the type that causes typhoid fever). This vaccine is recommended for people traveling to developing countries for extended periods. However, the type of Salmonella involved in the recent chocolate outbreak is not *Salmonella Typhi*, so the existing vaccine does not protect against it.

How is a Salmonella infection diagnosed?

Through stool sample testing.

The clinical appearance of diarrhea caused by Salmonella is similar to that caused by other organisms. Therefore, a stool sample must be taken for testing. The sample is analyzed using culture or PCR testing (yes, the same PCR method used for COVID-19 testing). If you want to learn more about stool testing and its pros and cons, please refer to this article here.

In cases where the infection spreads to the blood or other organs, the organism can also be isolated from those sources.

Who is at risk of developing an invasive Salmonella infection?

Children under the age of one (especially under 6 months), and the elderly.
People who are immunosuppressed.
People with chronic gastrointestinal diseases.
People with congenital heart disease, cardiovascular illness, severe atherosclerosis, or artificial valves and joints (as the bacteria tends to attach to artificial materials).
People with inherited red blood cell disorders affecting hemoglobin.

For individuals in these risk groups who become infected with Salmonella, antibiotic treatment is recommended.

How do you treat Salmonella?

As with most diarrheal illnesses, treatment is mainly supportive. This includes pain relief, fever-reducing medications, and encouraging proper food and fluid intake to prevent dehydration and electrolyte imbalance.

Antibiotics are generally not needed for healthy people with mild to moderate illness. Studies have not shown that antibiotics reduce the duration of illness; in fact, they may increase the length of time the bacteria are carried in the intestines.

Who needs antibiotic treatment?

Antibiotic treatment is recommended for individuals in the risk groups mentioned earlier or for those with severe illness. In these cases, antibiotics can help reduce the risk of complications and invasive disease.

You can find more information about diarrhea in children, the signs and symptoms of dehydration, and prevention strategies here.

What should I do about the Ferrero chocolate outbreak (or any similar outbreak)?

If you’ve eaten one of the affected chocolates and feel fine, there’s no need to worry.

If you’re experiencing diarrhea — with or without fever — consult your family doctor or pediatrician as you normally would, and discuss whether further evaluation is necessary.

If you belong to a risk group for severe disease, avoid consuming products that are suspected to be contaminated.

And just relax — there’s no need to panic.