Adenovirus Infections in Children
Content reviewed against published CDC, AAP, NIH guidelines
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Adenoviruses are a family of over 50 virus types that cause a wide range of illnesses in children, including upper and lower respiratory infections, conjunctivitis (pink eye), gastroenteritis, and croup. They account for approximately 5-10% of all respiratory infections in children. Adenovirus infections tend to be more severe and prolonged than typical colds, with high fevers lasting 5-7 days. They are extremely common in young children, especially those in daycare or group settings.
Key takeaways
- Adenoviruses are a family of over 50 virus types that cause a wide range of illnesses in children, including upper and lower respiratory infections, conjunctivitis (pink eye), gastroenteritis, and croup.
- Duration: Fever typically lasts 5-7 days (sometimes up to 10). Cough may persist 2-3 weeks. Conjunctivitis resolves in 1-2 weeks. GI symptoms (if present) last 5-12 days. Total illness may last 1-3 weeks.
- Go to ER if: Difficulty breathing, rapid breathing, or chest retractions
- No vaccine currently available
Symptoms
How It Presents by Age
0-6 months
Can cause severe illness including bronchiolitis and pneumonia. Fever may be high and prolonged. Higher risk of serious lower respiratory infection. May present with apnea episodes.
Risk level: Moderate to high
6 months-2 years
Very common age for adenovirus. High fever lasting nearly a week is typical. May have "pharyngoconjunctival fever" (sore throat, red eyes, and high fever). Often triggers ER visits due to prolonged high fever.
Risk level: Low to moderate
2-5 years
Peak age for adenovirus in group settings. Classic presentation with prolonged high fever, pharyngitis, and conjunctivitis. May have concurrent GI symptoms. Croup-like presentation possible.
Risk level: Low to moderate
5-12 years
Pharyngoconjunctival fever, respiratory illness, or isolated conjunctivitis. Epidemic keratoconjunctivitis can occur. Generally less severe but fever can still be prolonged.
Risk level: Low
Treatment
Supportive care
No specific antiviral treatment for most children. Management focuses on fever control, hydration, and symptom management. The illness must run its course.
Fever management
Acetaminophen and ibuprofen (6+ months), alternating if needed for persistent high fevers. Do not use aspirin. Fevers may be difficult to control and this is normal with adenovirus.
Eye care (conjunctivitis)
Cool compresses on eyes. Artificial tears for comfort. Antibiotic eye drops are not effective against viral conjunctivitis but may be prescribed to prevent secondary bacterial infection.
Cidofovir (severe cases)
Antiviral cidofovir may be considered for severe adenovirus in immunocompromised children (transplant patients). Not used for typical pediatric infections.
Home Care
- Alternate acetaminophen and ibuprofen for persistent fevers
- Keep child well-hydrated — offer fluids frequently
- Cool compresses for red, irritated eyes
- Use saline nasal drops for congestion
- Humidifier for cough and respiratory symptoms
- Rest — allow extra sleep as fever can last many days
- Reassure yourself that prolonged fever (up to 7 days) is normal for adenovirus
- Warm salt water gargle for sore throat (older children)
When to Worry
Go to the ER if:
- Difficulty breathing, rapid breathing, or chest retractions
- High fever in infant under 2 months
- Severe dehydration (no urine for 8+ hours, no tears, lethargic)
- Child appears extremely ill or unresponsive
- Seizure with fever
- Severe abdominal pain with bloody stool
Call your doctor if:
- High fever lasting more than 5 days (to rule out bacterial infection)
- Red eyes with significant discharge
- Persistent cough with worsening breathing
- Earache (common secondary ear infection)
- Child under 3 months with fever over 100.4°F
- Decreased urine output or signs of dehydration
- Child not improving after 7 days
Keep an eye on:
- Fever persisting beyond 7-8 days
- Difficulty breathing or rapid breathing developing
- Child becoming lethargic or very irritable
- Not drinking enough fluids (signs of dehydration)
- Fever improving then returning high (secondary infection)
- Eye discharge becoming thick or purulent with eyelid swelling
Prevention
- Frequent handwashing with soap and water
- Avoid sharing towels, pillows, and personal items
- Proper chlorination of swimming pools
- Avoid touching eyes, nose, and mouth
- Disinfect shared surfaces (adenovirus is resistant to many disinfectants — use bleach-based products)
- Keep sick children home from school/daycare
- No shared eye drops or cosmetics
Contagion & Incubation
Incubation
2-14 days depending on the type (respiratory: 2-14 days; gastroenteritis: 3-10 days)
Contagious for
Respiratory shedding for 1-2 weeks. Stool shedding can continue for weeks to months. Most contagious during the first few days of symptoms, but prolonged shedding makes containment difficult.
Duration
Fever typically lasts 5-7 days (sometimes up to 10). Cough may persist 2-3 weeks. Conjunctivitis resolves in 1-2 weeks. GI symptoms (if present) last 5-12 days. Total illness may last 1-3 weeks.
Frequently asked questions
How long does adenovirus infections in children last?
How does adenovirus infection spread?
When should I take my baby to the ER?
Can adenovirus infection be prevented?
When can my child return to daycare?
Sources
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources
Related Illnesses
Bottom line
Adenovirus Infections in Children is a viral illness that typically resolves on its own. Seek emergency care if difficulty breathing, rapid breathing, or chest retractions.
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.