Introduction

Definition of salmonella 

Salmonella is a genus of bacteria that causes salmonellosis, an infection typically characterised by gastrointestinal symptoms. These bacteria are commonly found in the intestines of animals and humans and can be transmitted through contaminated food or water.¹ The two main species of Salmonella that cause infections in humans are Salmonella enterica and Salmonella bongori. Salmonella enterica has numerous serotypes that are often implicated in foodborne outbreaks.

Importance of the topic 

Salmonella infections are particularly concerning in children due to their developing immune systems, which can lead to more severe symptoms and complications. Infections in children can result in prolonged illness, hospitalization, and, in severe cases, death. Understanding the causes, symptoms, diagnosis, treatment, prevention, and potential complications of Salmonella infections in children is crucial for managing and reducing the incidence of this public health issue. Preventive measures and early treatment can significantly reduce morbidity and mortality associated with these infections.

Causes of salmonella infections in children

Contaminated food and water 

The primary source of Salmonella infections is the consumption of contaminated food and water. Common culprits include undercooked or raw meat, particularly poultry, eggs, unpasteurized milk and dairy products, and contaminated fruits and vegetables.² Poor food handling and preparation practices can exacerbate the risk of contamination. Improper food storage, such as keeping food at unsafe temperatures, also contributes to the growth of Salmonella bacteria.

Animal contact

Children can contract Salmonella through direct or indirect contact with animals, particularly reptiles, amphibians, and birds, which are known carriers of the bacteria. Pets such as turtles, snakes, lizards, and chicks pose a significant risk.³ Children who handle these animals or their environments (such as cages and tanks) without proper handwashing are at increased risk. Public health campaigns often warn against keeping such pets in households with young children due to the heightened risk of transmission.

Person-to-person transmission 

Salmonella can also spread from person to person, especially in settings where hygiene practices are insufficient. This includes childcare centres, where young children may not consistently wash their hands after using the restroom.⁴ Infected individuals can shed the bacteria in their stool, and if proper hygiene is not practised, the bacteria can be transferred to surfaces, toys, and other children, perpetuating the spread of the infection.

Symptoms of salmonella infections in children

Gastrointestinal symptoms 

The primary symptoms of Salmonella infections include diarrhoea, abdominal cramps, nausea, and vomiting. These symptoms typically appear 6 to 72 hours after exposure to the bacteria.5 The diarrhoea can range from mild to severe and may sometimes be bloody, which is an indicator of a more severe infection.

Systemic symptoms 

In addition to gastrointestinal symptoms, children may experience systemic symptoms such as fever, headache, and muscle pain. These symptoms reflect the body's systemic inflammatory response to the infection. In some cases, children may also exhibit chills and general malaise. These symptoms can vary in intensity depending on the child’s immune status and the severity of the infection.⁶

Duration and severity 

Salmonella infections usually last between 4 to 7 days. However, young children, especially those under five years old, are at a higher risk of severe illness and complications due to their immature immune systems.⁷ In some cases, the infection can lead to dehydration, requiring hospitalization. Severe cases may involve the bacteria spreading to the bloodstream (bacteremia) or other body sites, leading to more serious conditions such as septicemia or meningitis.

Diagnosis of salmonella infections

Clinical examination 

Diagnosis begins with a thorough clinical examination, where healthcare providers assess symptoms and gather medical history, including recent food intake and potential exposure to contaminated sources such as undercooked meats, eggs, unpasteurized dairy products, or contaminated water.⁸ Additionally, they may inquire about recent travel history, particularly to areas where Salmonella infections are more prevalent, and any known contact with infected individuals or animals that could serve as carriers of the bacteria.

During the physical examination, clinicians look for signs indicative of a Salmonella infection, such as fever, abdominal tenderness, and signs of dehydration like dry mucous membranes or reduced skin turgor. This assessment helps determine the need for further diagnostic testing and the urgency of intervention.

Laboratory tests

Laboratory tests are essential for confirming a diagnosis of Salmonella infection and for identifying the specific serotype involved. The primary diagnostic test is a stool culture, where a sample of the patient’s stool is analyzed to detect the presence of Salmonella bacteria. This process involves culturing the stool sample on selective media that encourage the growth of Salmonella while inhibiting other bacteria. The results from stool cultures not only confirm the infection but also allow for antibiotic susceptibility testing, which guides treatment decisions if antibiotics are needed.

In severe cases, particularly when systemic involvement is suspected, blood cultures may be performed to check for bacteremia, which is the presence of bacteria in the bloodstream. This is crucial for patients exhibiting signs of systemic infection, such as high fever and persistent vomiting, as it indicates a more serious progression of the illness that requires immediate and aggressive treatment.

Advancements in diagnostic techniques have introduced rapid diagnostic tests and polymerase chain reaction (PCR) assays, which provide quicker identification of Salmonella. These methods can detect bacterial DNA in stool samples, offering results much faster than traditional culture methods. While PCR assays are highly sensitive and specific, they are also more costly and not as widely available in all healthcare settings.

Imaging studies, although rarely used, may be employed if complications such as abscesses or bowel perforation are suspected. These complications are more common in severe or prolonged cases and necessitate detailed visualization to plan appropriate interventions.⁹

Treatment of salmonella infections

Hydration and nutrition 

The cornerstone of treating Salmonella infections is maintaining hydration and nutrition. Oral rehydration solutions are often recommended to prevent dehydration caused by diarrhoea and vomiting.¹⁰ These solutions contain a balanced mix of salts and sugars that help replenish lost fluids and electrolytes more effectively than plain water. For children who are unable to maintain adequate hydration through oral intake, intravenous (IV) fluids may be necessary. IV rehydration is particularly important in cases of severe dehydration, where oral rehydration is insufficient or impractical.

Nutritional support also plays a vital role. Children should be encouraged to continue eating small, frequent meals that are easy to digest. The BRAT diet (bananas, rice, applesauce, toast) is commonly recommended during the acute phase of the illness. Gradual reintroduction of a regular diet can occur as symptoms improve.

Medication 

Antibiotics are generally not prescribed for uncomplicated Salmonella infections, as their use can prolong the carrier state where the bacteria remain in the intestines and are shed in the stool for an extended period. However, in severe cases or for children who are at high risk of complications, such as those with weakened immune systems, antibiotics may be necessary. The choice of antibiotic and duration of therapy depends on the severity of the infection and the specific Salmonella serotype involved.

Antipyretics, such as acetaminophen or ibuprofen, can be used to manage fever and alleviate discomfort. Antiemetics may be prescribed to control severe vomiting, thus helping maintain oral intake and preventing dehydration.¹¹

Hospitalization

Hospitalization is required for children who develop severe dehydration, systemic infection, or other complications. In the hospital setting, children receive intravenous fluids, electrolytes, and medications under close supervision. Continuous monitoring ensures timely intervention if the patient's condition worsens or complications arise. Hospital care may also include supportive treatments such as pain management and nutritional support through tube feeding if necessary.¹²

Prevention of salmonella infections

Food safety practices 

Preventing Salmonella infections involves stringent adherence to food safety practices. Key measures include cooking meat and eggs to safe internal temperatures, which effectively kill Salmonella bacteria. Avoiding cross-contamination in the kitchen is also critical; this means using separate cutting boards and utensils for raw meats and other foods, and thoroughly cleaning surfaces and hands after handling raw meat.

Proper storage of food is another important preventive measure. Perishable items should be refrigerated promptly to inhibit bacterial growth, and foods should be consumed within their recommended time frames to avoid spoilage. Educating families about the risks of consuming raw or undercooked eggs, unpasteurized dairy products, and raw sprouts can also reduce infection rates.¹³

Personal hygiene

Personal hygiene, particularly handwashing, is a cornerstone of preventing the spread of Salmonella. Children should be taught proper handwashing techniques and encouraged to wash their hands frequently, especially before eating, after using the restroom, and after handling animals. Effective handwashing involves using soap and running water, scrubbing all parts of the hands for at least 20 seconds, and drying them with a clean towel.

Parents and caregivers should also model good hygiene practices and ensure that young children are supervised during handwashing to reinforce these habits.¹⁴

Safe animal handling 

Handling animals safely is crucial in preventing Salmonella infections, particularly in households with young children. Children should wash their hands thoroughly after touching pets, especially reptiles and amphibians, which are known carriers of Salmonella. Public health guidelines often advise against keeping high-risk pets, such as turtles and snakes, in homes with children under five years old.

Additionally, families should be educated on proper cleaning and maintenance of pet habitats to minimize the risk of environmental contamination. Keeping pets out of areas where food is prepared or consumed can further reduce the likelihood of infection.¹⁵

Complications of salmonella infections

Dehydration

Dehydration is a common and potentially severe complication of Salmonella infections, resulting from extensive fluid loss due to diarrhoea and vomiting. Symptoms of dehydration include dry mouth, decreased urine output, sunken eyes, and lethargy. In severe cases, dehydration can lead to hypovolemic shock, a life-threatening condition that requires immediate medical intervention. Preventing and treating dehydration through adequate fluid intake is essential to managing this complication ⁽¹⁶⁾. 

Severe infections 

In rare instances, Salmonella can lead to severe infections such as bacteremia, sepsis, and reactive arthritis. Bacteremia occurs when the bacteria enter the bloodstream, potentially spreading to other organs and causing systemic infection. This condition can progress to sepsis, a severe and life-threatening response to infection characterized by widespread inflammation, tissue damage, and organ failure.

Reactive arthritis, an autoimmune condition triggered by an infection, can develop in some children following a Salmonella infection. It is characterized by joint pain, swelling, and inflammation. Early recognition and treatment of these severe infections are crucial for preventing long-term health issues.¹⁷

Long-term gastrointestinal issues 

Some children may experience long-term gastrointestinal issues following a Salmonella infection, including irritable bowel syndrome (IBS). IBS is a chronic condition that involves recurrent abdominal pain, bloating, and changes in bowel habits. It can significantly impact a child’s quality of life and may require ongoing medical management, including dietary modifications and medications to alleviate symptoms.¹⁸

Summary 

Salmonella infections in children are a significant public health concern due to their potential severity and complications. Diagnosing these infections accurately involves clinical examination and laboratory tests, while effective treatment focuses on hydration, supportive care, and in severe cases, hospitalization. Preventive measures, including food safety practices, personal hygiene, and safe animal handling, are crucial for reducing infection rates. Raising awareness among parents, caregivers, and healthcare providers about Salmonella infections and implementing preventive measures can help reduce the incidence and impact of these infections in children. Public health campaigns and education can play a pivotal role in enhancing food safety practices and personal hygiene, thereby protecting children from this preventable illness.