Summary Points

• Acute respiratory disease is often caused by adenoviruses and is common among children and military recruits
• The incubation period is generally 5-8 days
• Conjunctivitis is also seen in adenovirus infections
• Acute hemorrhagic cystitis can also occur and is more common in boys
• Gastrointestinal disease can also occasionally be attributed to adenovirus infection

Respiratory Disease caused by Adenovirus

Respiratory symptoms caused by adenoviruses are most commonly seen amongst children under the age of two. The incubation period before the onset of these symptoms is generally 5-8 days. Patients most often complain of symptoms including pharyngitis (sore throat), fever, cough, croup, and bronchiolitis. While all of these symptoms are common to many viral infections, if they are accompanied by conjunctivitis, adenovirus infection becomes a much more likely candidate for the cause of infection.

A common complication of adenovirus infection is the development of pneumonia. Approximately 10% of all childhood pneumonias are caused by adenovirus infections.

Conjunctivitis caused by Adenovirus

Conjunctivitis caused by adenovirus infection is a more serious manifestation of the virus. This form of adenovirus infection is highly contagious and will often spread from one eye to the other. The serotypes that cause conjunctivitis infections can be transmitted in swimming pools with insufficient chlorination or from eye equipment that has not been properly sterilized.

Acute Hemorrhagic Cystitis

Occasionally adenoviruses can cause patients to have painful and bloody urine. These symptoms are more commonly associated with serotypes 11 and 21 and generally seen in younber boys, in ages 6 -15. The bloody urine will generally persist for three days. Blood in urine should be distinguished from more serious types of infections; the differential diagnosis includes bacterial cystitis, stones, and tumors. Hematuria (urine containing blood) can be distinguished from more serious infections by imaging tests; adenovirus infection usually does not cause the patient to have renal or bladder abnormalities when they are imaged with X-rays.

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Acute Gastroenteritis

Gastrointestinal symptoms, including abdominal pain and diarrhea have been reported and are caused by serotypes 40 and 41. In children, respiratory symptoms are also commonly found with gastrointestinal infections. These infections, while not often identified as being specifically caused by adenoviruses, are quite common - studies have shown that 50% of children have antibodies to adenoviruses by the age of 4.

Adenovirus is also associated with intussusception in younger children. However, the association is not with the enteric strain of adenoviruses; instead they are linked to serotypes 1, 2, 5, and 6. The exact mechanism by which adenovirus infection gives people a higher risk of intussusception is unknown.

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