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 that first discovered them, Daniel Salmon.

How can you get infected with Salmonella?

The most common way to get Salmonella is through consumption of food products contaminated with Salmonella. Salmonella reaches these food products from infected animals – eggs, chicken, undercooked meat, dairy products or from fresh products washed using 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 so on. Also, one can get infected through contact with an infected person’s stool. Transmission of infection between family members is therefore very common.

How infectious is Salmonella?

In infectious diseases, there is a term known as “inoculum,” commonly used to describe the quantity of pathogen (usually virus or bacteria), needed to cause disease. For Salmonella, an inoculum of 1,000,000 bacteria is to be consumed for illness to occur.
Why is this so important? In contrast to other infectious organisms, for which the inoculum can be much lower (as low as 10), when it comes to Salmonella, one needs to consume quite a large quantity of organisms for them to develop disease. Or, in other words, that same kinder egg needs to contain about a million Salmonella organisms for the consumer to get sick.

What kind of symptoms does Salmonella illness result in?

It depends on the age and general health condition of the person infected. In the majority of healthy individuals, the symptoms range between asymptomatic illness (no symptoms at all), to transitory diarrhea. Gastrointestinal symptoms start to develop usually following incubation of up to two days from the exposure. These symptoms include abdominal pain, diarrhea (may or may not be bloody), nausea and vomiting. Sometimes, you can also get fever and chills. In healthy individuals, the fever will usually resolve within two to three days and the diarrhea resolves within a few days to one week.
I advise you to read the pivotal chapter about diarrhea in children on my website here, where you can learn about the different types of diarrhea out there, including watery, bloody and mucosal, as well as look through some pictures.
It is important to emphasize that most people who get infected with Salmonella continue to carry the organism in their intestines for a short period of time and may secrete it from their intestines for a period of about 5-7 weeks following the infection. This asymptomatic carriage does not require any further workup or treatment. In people with a medical history (mainly immunosuppression), younger infants and elders, the illness can be much more significant and dangerous as you will see later in this chapter.

So, is getting infected with Salmonella dangerous?

As I previously mentioned, most cases of Salmonella infections in healthy individuals will lead to diarrhea that will resolve on its own. Sometimes, this infection can last for a longer period and require hospitalization for treatment and fluids.
Rarely, in up to 5% of those infected that we know about, (remember that that are many people who get Salmonella but remain asymptomatic, so we never actually come around to diagnosing them), the infection breaks into the bloodstream through the intestines and settles in different organs and vessels.
Such complications occur mostly in patients with risk factors, as you will see later in this chapter.

Is there a vaccine against Salmonella?

I started off by explaining that there are several different types of Salmonella.
There is a vaccination against Salmonella Typhi (the abdominal type). This vaccine is recommended for those travelling to developing countries for extended periods of time. The Salmonella I am currently discussing in this chapter, the own that was found in the chocolate outbreak, is not Salmonella Typhi and so the vaccination that exists doesn’t cover it.

How is Salmonella infection diagnosed?

Stool sample testing.
The clinical presentation of the stool produced by Salmonella bacteria isn’t any different from the diarrhea caused by any other organism. Therefore, stool sampling needs to be done. The stool sample taken from the patient is sent for culture or PCR testing (yes, that same PCR testing method that we are familiar with from COVID-19 testing). If you would like to read more about the different types of stool testing and their advantages and disadvantages, please refer to this article here.
In cases where an infection develops in the blood or one of the bodily organs – the organism can be isolated from those sources as well.

Who are the people at risk of developing an invasive Salmonella infection?

Age – children under the age of one (more so under the age of 6 months) and elders.
People that are immunosuppressed.
People that suffer from chronic gastrointestinal diseases.
People with congenital heart disease and cardiovascular illness, severe atherosclerosis, artificial valves and joints (if the bacteria is able to break into the blood it loves lodging on artificial devices).
People with inherent diseases in hemoglobin of red blood cells.
For people who get infected with Salmonella and belong to one of these risk groups, we recommend starting an antibiotic treatment.

How do you treat Salmonella?

Just like any other diarrheal disease, treatment is mostly supportive and includes painkillers, fever-reducing medications, encouraging adequate food and fluid consumption for prevention of dehydration or salt and mineral imbalance.
When it comes to antibiotics – most healthy people with mild to moderate disease do not need to be treated with antibiotics; their disease will resolve on its own. Evidence has not only been unable to prove that antibiotic treatment reduces the length of illness but has shown longer periods of organism carriage in the intestines.

Who needs antibiotic treatment?

Those people that fall into one of the risk groups I described earlier or in people with severe illness. Treatment of these patients with antibiotics can reduce the risk of invasive disease.
You can find more information about diarrhea in children, the signs and symptoms of dehydration and how to prevent it here.

What do I need to do now about the Ferrero chocolate outbreak (or any other outbreak)?

If you have had one of these chocolates and are feeling well, just forget about it.
If you are suffering from diarrhea, with or without fever, refer to your family doctor or pediatrician as you would usually, and discuss the need for further workup together.
Especially if you belong to one of the groups at risk of developing severe disease, make sure not to consume products that are suspected to have been contaminated.

And just relax, there’s no reason to worry.