Infection with one of the many adenoviruses may be asymptomatic or result in specific syndromes, including mild respiratory infections, keratoconjunctivitis, gastroenteritis, cystitis, and primary pneumonia. Diagnosis is clinical. Treatment is supportive.
Adenoviruses are DNA viruses classified according to 3 major capsid antigens (hexon, penton, and fiber). Adenoviruses are commonly acquired by contact with secretions (including those on fingers of infected people) from an infected person or by contact with a contaminated object (eg, towel, instrument). Infection may be airborne or waterborne (eg, acquired while swimming). Asymptomatic respiratory or GI viral shedding may continue for months, or even years.
In immunocompetent hosts, most adenovirus infections are asymptomatic; when infections are symptomatic, a broad spectrum of clinical manifestations is possible. The most common syndrome, especially in children, involves fever that tends to be > 39° C and to last > 5 days. Sore throat, cough, rhinorrhea, or other respiratory symptoms may occur. A separate syndrome involves conjunctivitis, pharyngitis, and fever (pharyngoconjunctival fever). Rare adenoviral syndromes in infants include severe bronchiolitis (see Bronchiolitis) and pneumonia. In closed populations of young adults (eg, military recruits), outbreaks of respiratory illness may occur; symptoms include fever and lower respiratory tract symptoms, usually tracheobronchitis but occasionally pneumonia.
Epidemic keratoconjunctivitis (see Etiology) is sometimes severe and occurs sporadically and in epidemics. Conjunctivitis is frequently bilateral. Preauricular adenopathy may develop. Chemosis, pain, and punctate corneal lesions that are visible with fluorescein staining may be present. Systemic symptoms and signs are mild or absent. Epidemic keratoconjunctivitis usually resolves within 3 to 4 wk, although corneal lesions may persist much longer.
Nonrespiratory adenoviral syndromes include hemorrhagic cystitis, diarrhea in infants, and meningoencephalitis.
Most patients recover fully. Even severe primary adenoviral pneumonia is not fatal except for rare fulminant cases, predominantly in infants, military recruits, and immunocompromised patients.
Treatment is symptomatic and supportive. Ribavirin and cidofovir have been used in immunocompromised patients; results varied.
To minimize transmission, heath care practitioners should change gloves and wash hands after examining infected patients, sterilize instruments adequately, and avoid using ophthalmologic instruments in multiple patients.
Vaccines containing live adenovirus types 4 and 7, given orally in an enteric-coated capsule, can reduce lower respiratory disease. The vaccine was unavailable for a number of years but was reintroduced in 2011. However, it is available only for military personnel. It may be given to patients aged 17 through 50 yr and should not be given to women who are pregnant or breastfeeding.