Recognised patterns of clinical features include respiratory, eye, gastrointestinal, genitourinary and central nervous system. There is also a widespread type that occurs in immunocompromised people. Typical symptoms are of a mild cold or resembling the flu; fever, nasal congestion, coryza, cough, and pinky-red eyes. Infants may also have symptoms of an ear infection. Onset is usually two to fourteen days after exposure to the virus. There may be tiredness, chills, muscle aches, or headache. However, some people have no symptoms. Generally, a day or two after developing a sore throat with large tonsils, glands can be felt in the neck. Illness is more likely to be severe in people with weakened immune systems, particularly children who have had a hematopoietic stem cell transplantation. Sometimes there is a skin rash. Respiratory tract
Preschool children with adenovirus colds tend to present with a nasal congestion, runny nose and abdominal pain. There may be a harsh barking cough. It is frequently associated with a fever and a sore throat. Up to one in five infants with bronchiolitis will have adenovirus infection, which can be severe. Bronchiolitis obliterans is uncommon, but can occur if adenovirus causes pneumonia with prolonged fever, and can result in difficulty breathing. It presents with a hyperinflated chest, expiratory wheeze and low oxygen. Severe pneumonia is most common in very young children age three-to-18 months and presents with sudden illness, ongoing cough, high fever, shortness of breath and a fast rate of breathing. There are frequently wheezes and crackles on breathing in and out.
A live adenovirus vaccine to protect against types 4 and 7 adenoviruses has been used in some military personnel. Rates of adenovirus disease fell among military recruits following the introduction a live oral vaccine against types 4 and 7. Stocks of the vaccine ran out in 1999 and rates of disease increased until 2011 when the vaccine was re-introduced. Treatment
Treatment is generally symptomatic and supportive. Medicines to ease pain and reduce fever can be bought over the counter. For adenoviral conjunctivitis, a cold compress and lubricants may provide some relief of discomfort. Steroid eye drops may be required if the cornea is involved. Most adenovirus infections get better without any treatment. Prognosis
After recovery from adenovirus infection, the virus can be carried for weeks or months.Adenovirus can cause severe necrotizing pneumonia in which all or part of a lung has increased translucency radiographically, which is called Swyer-James Syndrome. Severe adenovirus pneumonia also may result in bronchiolitis obliterans, a subacute inflammatory process in which the small airways are replaced by scar tissue, resulting in a reduction in lung volume and lung compliance. Epidemiology
Adenovirus infections occur sporadically throughout the year, and outbreaks can occur particularly in winter and spring. Epidemics may spread more quickly in closed populations such as in hospitals, nurseries, long-term care facilities, boarding schools, orphanages and swimming pools. Severe disease is rare in people who are usually healthy. Around 10% of respiratory infections in children are caused by adenoviruses.