Introduction 

Adenovirus is a common virus that can cause various symptoms. It spreads through coughing, sneezing, or touching infected surfaces. There are different types of adenovirus, each causing different symptoms. While most cases are mild and resolve on their own, severe cases can occur, especially in babies and people with weakened immune systems.

Newborns are more vulnerable to infections because their immune systems are still developing. Adenovirus can be particularly risky for them, leading to severe respiratory problems, pneumonia, or even death in rare cases. Recognising symptoms early is crucial because prompt medical attention can prevent complications and save lives. Symptoms in newborns may include fever, difficulty breathing, poor feeding, and irritability. Since newborns cannot communicate their discomfort, parents must closely observe any signs of illness and seek medical help if needed.

By understanding the risks and being vigilant, parents can help protect their newborns from complications associated with adenovirus infections. In providing simple and clear information, this article hopes to empower parents to take proactive steps in safeguarding their baby's health.

What is adenovirus? 

Adenoviruses, or AdVs, are tiny viruses that contain double-stranded DNA in their genome. Since their discovery in 1953,^1,2 over 120 types of adenoviruses have been identified, affecting humans, animals, birds, fish, and reptiles.^3,4 Human adenoviruses typically cause mild illnesses in healthy individuals but can lead to severe infections in those with weakened immune systems.^5,7 Animal adenoviruses, on the other hand, are associated with significant diseases in animals and birds. AdVs belong to the Adenoviridae family and are grouped into six genera based on their genetic makeup.^8,9

How adenovirus spreads 

Adenoviruses spread through various means, including inhalation of droplets carrying the virus, direct contact with infected eyes, fecal-oral transmission, or exposure to infected tissues or blood. The incubation period varies depending on the specific adenovirus type and mode of transmission, ranging from 2 days to 2 weeks.¹⁰ Infected individuals can shed the virus through respiratory secretions, stool, or eye discharge for different durations, depending on the type of illness.

Common types of adenovirus infections

Adenovirus infections occur worldwide and throughout the year, with no significant seasonal variation. Most infections are sporadic, but localised or regional outbreaks can occur, especially in crowded or closed environments.^11,12 Children, individuals living in close quarters, such as college dormitories or military barracks, and those with weakened immune systems are at higher risk.^13,14,15 While adenovirus infections in healthy individuals are usually self-limiting, they can cause severe disease in patients with a weakened immune system, such as those who have undergone stem cell or solid organ transplants. These severe infections can involve multiple organs and have a higher mortality rate. Adenovirus infections are commonly detected through stool cultures, especially during the first two weeks of illness, and may persist intermittently for months or even years, in some cases.

Adenovirus in newborns 

Vulnerability of newborns to infections 

Newborns and young infants are especially vulnerable to infections as their immune systems are still developing. Unlike older children and adults, newborns have immature immune responses, particularly in the innate immune system innate immunity is the body's first line of defense against infections, but in newborns, it may not be fully developed, leaving them more susceptible to intracellular pathogens like adenovirus. Their adaptive immune system, responsible for specific responses to pathogens, is also naive at birth, adding to their vulnerability.

Risk factors for adenovirus in newborns 

Adenovirus infections in neonates are rare but can be life-threatening. Neonatal transmission of adenovirus can occur vertically from the mother or horizontally from other family members. Horizontal transmission is more likely when neonatal symptoms appear around 16 days of age on average.^{16, 17} Adenoviruses are highly stable and easily spread through respiratory secretions, contaminated hands, surfaces, and equipment. Newborns with adenovirus infections can present with a wide range of symptoms, from asymptomatic to fatal, depending on their immunological status.

Importance of early detection and treatment

Early detection and prompt treatment of adenovirus infections in newborns are crucial for improving outcomes. Adenoviral infections can manifest differently depending on the immune status of the newborn, ranging from mild flu-like symptoms to severe respiratory or gastrointestinal complications. Diagnosis typically involves various laboratory tests like PCR or viral cultures from infected sites.^18,19 While there's no specific antiviral therapy approved for adenovirus, reducing the viral load with medications like cidofovir or ribavirin, along with supportive care, can help manage symptoms. In severe cases, treatments like intravenous immunoglobulin (IVIG) or virus-specific T-cell lymphocytes may be considered. Despite advancements in treatment, adenovirus infections in newborns still carry high morbidity and mortality rates,²⁰ highlighting the need for further research into new therapeutic strategies. Early detection allows for timely intervention, potentially preventing severe complications and improving the chances of recovery for newborns infected with adenovirus.

Recognizing adenovirus symptoms in newborns 

Respiratory symptoms 

• Runny nose
• Sore throat
• Fever
• Severe cough
• Swollen lymph nodes
• Pink eye
• Chest cold (bronchitis)
• Pneumonia

Gastrointestinal symptoms 

• Watery diarrhoea that starts suddenly
• Fever
• Belly (abdominal) pain
• Vomiting
• Gastroenteritis (inflammation of the stomach or intestines)

Fever and other general symptoms

• Fever may accompany both respiratory and gastrointestinal symptoms

Other possible symptoms

• Eye redness and pain
• Diarrhea
• Frequent peeing, burning pain while peeing, blood in the urine
• Headache
• Conditions affecting the nervous system, such as encephalitis and meningitis

When to seek medical help 

Urgent symptoms that require immediate medical attention 

• High fever or fever lasting more than a few days
• Breathing problems
• Red eyes, eye pain, or change in vision
• Severe diarrhoea, vomiting, or signs of dehydration like peeing less, dry mouth, sunken eyes, acting tired

Importance of consulting a healthcare provider for any concerning symptoms

Even if symptoms seem mild, it is important to seek medical help if they don't improve or worsen. New symptoms should also prompt a call to the healthcare provider. Remember, you know your child best. If they seem very ill, don't hesitate to contact the doctor right away.

For adenovirus infections in children, treatment focuses on easing symptoms. Antibiotics don't work against adenoviruses. Treatment may include giving more fluids, medicines to help breathing for respiratory symptoms, and oral rehydration for digestive symptoms. Severe cases, especially in infants or those with weak immune systems, may require hospitalisation for IV fluids, tube feedings, and other supportive measures.

Complications of adenovirus infections can include chronic lung disease, severe infections in individuals with weakened immune systems, and intussusception, a serious intestinal condition mostly seen in babies where a portion of the intestine slides into the next section.²¹ If your child's symptoms persist or worsen, it's crucial to contact the healthcare provider promptly.

Preventing adenovirus infections involves good hygiene practices like frequent handwashing, avoiding close contact with sick individuals, and disinfecting commonly touched surfaces.²² While there's currently no vaccine available to the general public, these preventive measures can help reduce the risk of infection. If you or your child experience symptoms, rest, stay hydrated, and seek medical advice if symptoms persist or worsen.

Conclusion 

In conclusion, recognising adenovirus symptoms in newborns is vital for early intervention and ensuring their well-being. Key symptoms include respiratory and gastrointestinal manifestations such as runny nose, sore throat, fever, severe cough, diarrhoea, abdominal pain, and vomiting. Additionally, fever and other general symptoms like eye redness and pain should not be overlooked. Prompt medical attention is crucial, especially for urgent symptoms such as high fever, breathing difficulties, or signs of dehydration. Parents play a crucial role in observing and responding to their newborn's health, as early detection can prevent complications and save lives.

It's essential for parents to stay informed about adenovirus symptoms and seek medical help if they notice any concerning signs. While most cases resolve with supportive care, severe infections can occur, particularly in infants and those with weakened immune systems. Treatment focuses on symptom management, as antibiotics are ineffective against adenoviruses. Complications such as chronic lung disease or severe infections underscore the importance of proactive medical care.

Moreover, preventive measures like frequent handwashing, avoiding close contact with sick individuals, and disinfecting surfaces can reduce the risk of adenovirus transmission. While there's currently no vaccine available to the general public, maintaining good hygiene practices can help protect newborns from infections.

In essence, staying vigilant, seeking timely medical care, and practising preventive measures are crucial in safeguarding newborns from adenovirus infections. By remaining informed and proactive, parents can contribute to their newborn's health and well-being.