adenovirus infection

What Is It?
An adenovirus infection is caused by a group of common viruses that can infect the lining of your eyes, airways, lungs, intestines, urinary tract, and nervous system. These infections range from mild to severe and are especially common in children, though they can affect people of any age. Adenoviruses are highly contagious and can spread through close contact, airborne droplets, or contaminated surfaces.

Why It Matters
While most adenovirus infections cause mild illness and resolve without treatment, they can lead to serious complications, particularly in infants, elderly adults, and people with weakened immune systems. Certain strains have been linked to outbreaks in military recruits and closed communities like daycares or nursing homes. Some forms can even lead to pneumonia, bladder infections, or neurologic diseases.

Key Facts (At a Glance)

  • Virus Type: Over 50 known human adenovirus types

  • Common Age Group: Mostly affects children under age 5

  • Transmission: Touching contaminated surfaces, droplets, fecal-oral route

  • Seasonality: Occurs year-round, but some types peak in late winter and early spring

  • Infectious Period: Virus can be shed for weeks, even after symptoms improve

How It Affects the Body
Once adenovirus enters the body, it targets mucous membranes—the moist linings of organs and tissues. The virus replicates and triggers an inflammatory immune response, leading to symptoms depending on the area affected:

  • In the respiratory tract: causes cold-like symptoms or bronchitis

  • In the gastrointestinal tract: leads to vomiting and diarrhea

  • In the eyes: causes conjunctivitis ("pink eye")

  • In the urinary tract: may trigger bladder inflammation (cystitis)

Common Symptoms
Symptoms depend on the part of the body infected but may include:

  • Fever and sore throat

  • Runny nose or nasal congestion

  • Cough and sneezing

  • Red, irritated eyes (conjunctivitis)

  • Diarrhea, vomiting, or abdominal pain

  • Painful urination (especially in children)

  • Rash (in some strains)

  • Fatigue or body aches

Risks & Side Effects
Most healthy people recover in 7–10 days, but potential complications include:

  • Pneumonia or severe respiratory illness

  • Ear infections

  • Conjunctivitis outbreaks (very contagious)

  • Bladder infections in children

  • Encephalitis or meningitis (rare, but serious)

  • Long viral shedding in immunocompromised patients

Who Should Be Cautious

  • Infants and young children

  • People with weakened immune systems (e.g., transplant recipients, chemotherapy patients)

  • Individuals in close-living settings (e.g., dorms, military barracks)

  • Unvaccinated military recruits (vaccine is available for types 4 and 7 in military use only)

  • People with chronic lung conditions, like asthma or COPD

When to See a Doctor
You should seek medical care if:

  • Fever lasts more than 3 days

  • Symptoms worsen or don’t improve after a week

  • Signs of dehydration appear (dry mouth, reduced urination, dizziness)

  • Breathing becomes difficult

  • A child has bloody diarrhea or severe eye redness/swelling

Related Conditions / Interactions

  • Conjunctivitis (Pink Eye)

  • Acute Gastroenteritis (especially in infants)

  • Bronchiolitis and pneumonia in young children

  • May exacerbate asthma or cause reactive airway symptoms

Last Updated: June 15, 2025