Salmonellosis: symptoms and signs in adults and children

In 2022, 65,208 laboratory-confirmed cases of salmonellosis were reported in EU countries — 15.3 per 100,000 population — and almost 39% of those affected were hospitalized. In 2022, salmonellosis was the second most frequently reported foodborne intestinal infection in EU countries, and its typical "gateways" are raw poultry, eggs, meat, and unwashed vegetables and fruits. Below are the signs that help suspect this infection in an adult and in a child.

What salmonellosis is

Salmonellae are a group of intestinal bacteria of the Enterobacteriaceae family: they colonize the small intestine, colonize the intestinal wall, and release exotoxins. The toxins cause fluid loss through the intestine, impair vascular tone, and damage the nervous system — hence the combination of diarrhea, weakness, and headache. The mechanism of transmission is fecal-oral, the main route is foodborne, through products of animal origin; the source can be animals and humans, but animals play the leading role in epidemiology. The incubation period is from 6 hours to 3 days, on average 12–24 hours. The disease does not always announce itself with symptoms: a person may remain a bacterial carrier, with no symptoms, while the pathogen is shed into the environment.

First signs of salmonellosis

The picture usually unfolds soon after suspicious food. Most commonly noted are:

• rise in body temperature;
• general weakness and headache;
• nausea, vomiting, loss of appetite;
• abdominal pain;
• repeated loose watery stools.

In most people, symptoms last 4–7 days: diarrhea usually stops within 5–7 days, vomiting within 1–2 days.

Symptoms of salmonellosis in adults

In adults with full-blown forms, fever, weakness, headache, nausea, vomiting, abdominal pain, and repeated loose watery stools are most often noted. Severe course leads to dehydration, enlargement of the liver and spleen, and in rare cases to renal failure. A generalized form is distinguished separately, when the pathogen enters the bloodstream: this condition is considered serious. Older people, infants, and people with chronic diseases tolerate the infection more severely than others.

Symptoms of salmonellosis in children

In children the set of signs is the same — fever, diarrhea, abdominal cramps, nausea, and vomiting. Signs of dehydration in a child under 5 years — for example, fewer wet diapers — are a reason to see a doctor. In children, vomit may be yellow-green or green. If an infant stops taking the breast or bottle, this is a reason to see a doctor without delay.

Complications and dangerous signs

Dangerous consequences include dehydration, enlargement of the liver and spleen, renal failure, and in rare cases death. European statistics for 2022: 38.9% of those affected were hospitalized, and the case fatality rate was 0.22%. Some of those who recover become carriers: there are no symptoms, but the person can infect others. Prolonged diarrhea lasting more than 7 days and vomiting lasting more than 2 days are concerning.

How the diagnosis is confirmed and when to see a doctor

The diagnosis is made comprehensively: epidemiological data are taken into account — what and where the person ate, whether they had contact with animals, especially reptiles — along with symptoms and laboratory tests. The main method is stool testing, which allows isolation of the pathogen; for typing salmonellae, the indirect (passive) hemagglutination test is used. The doctor assesses the degree of dehydration, the duration of symptoms, and the general condition.

You should see a doctor if diarrhea lasts more than 7 days, vomiting lasts more than 2 days, there are signs of dehydration, blood in the stool, or bleeding from the anus. A separate group is infants under one year and children who have stopped drinking.

Salmonellosis by itself is not a reason to call an ambulance: numbers 103 and 112 are needed if vomiting of blood or material resembling coffee grounds appears; green vomit in an adult or yellow-green or green vomit in a child; a stiff neck with pain when looking at bright light; sudden severe headache; sudden sharp abdominal pain; bluish, gray, pale, or mottled skin, lips, or tongue; severe difficulty breathing or frequent short breaths; confusion and an unusual reaction to what is happening.

This material is for reference: it helps to recognize the signs of the disease, but only a doctor can assess the condition and make a diagnosis.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer