 |
Infection
with one of the many adenoviruses may be asymptomatic or result
in specific syndromes, including mild respiratory infections, keratoconjunctivitis,
gastroenteritis, 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 finger transmission) from an infected person or by contact with a contaminated object (eg, towel, instrument). Infection may be airborne or waterborne (eg, acquired by swimming). Respiratory or GI viral shedding may continue for months, even if infection is asymptomatic.
Symptoms,
Signs, and Diagnosis
In immunocompetent hosts, most adenovirus infections are asymptomatic; when 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 Respiratory Disorders in Neonates, Infants, and Young Children: 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 Conjunctival and Scleral Disorders: Viral Conjunctivitis) is sometimes severe and occurs both 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 or 4 wk, although corneal lesions may persist much longer. Nonrespiratory adenoviral syndromes include hemorrhagic cystitis, diarrhea in infants, and meningoencephalitis.
Laboratory diagnosis of adenovirus infection rarely affects management. During the acute illness, virus can be isolated from respiratory and ocular secretions and frequently from stool and urine. A 4-fold rise in the serum antibody titer indicates recent adenoviral infection.
Prognosis,
Treatment,
and Prevention
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.
To minimize transmission, heath care practitioners should change gloves and wash hands after examining infected patients, properly sterilize instruments, and avoid using ophthalmologic instruments in multiple patients.
Vaccines containing live adenovirus types 4 and 7, given orally in an enteric-coated capsule, have previously reduced lower respiratory disease in military populations; however, these vaccines are no longer available.
Last full review/revision November 2005
Content last modified November 2005
| |
