Adenovirus infection is a contagious viral disease, caused by Adenoviruses, commonly resulting in a respiratory tract infection. Typical symptoms range from those of a common cold, such as nasal congestion, coryza and cough, to difficulty breathing as in pneumonia. Other general symptoms include fever, fatigue, muscle aches, headache, abdominal pain and swollen neck glands. Onset is usually two to fourteen days after exposure to the virus. A mild eye infection may occur on its own, combined with a sore throat and fever, or as a more severe adenoviral keratoconjunctivitis with a painful red eye, intolerance to light and discharge. Very young children may just have an earache. Adenovirus infection can present as a gastroenteritis with vomiting, diarrhoea and abdominal pain, with or without respiratory symptoms. However, some people have no symptoms.Adenovirus infection in humans are generally caused by Adenoviruses types B, C, E and F. Spread occurs mainly when an infected person is in close contact with another person. This may occur by either fecal–oral route, airborne transmission or small droplets containing the virus. Less commonly, the virus may spread via contaminated surfaces. Other respiratory complications include acute bronchitis, bronchiolitis and acute respiratory distress syndrome. It may cause myocarditis, meningoencephalitis or hepatitis in people with weak immune systems.Diagnosis is by signs and symptoms, and a laboratory test is not usually required. In some circumstances, a PCR test on blood or respiratory secretions may detect adenovirus DNA. Other conditions that appear similar include whooping cough, influenza, parainfluenza, and respiratory syncytial virus.
Adenovirus infection may result in symptoms of myocarditis, dilated cardiomyopathy, and pericarditis. Other signs and symptoms depend on other complications such as dark urine, itching and jaundice in hepatitis, generally in people who have a weakened immune system. Adenovirus is a rare cause of urethritis in men, when it may present with burning on passing urine associated with red eyes and feeling unwell. Cause and mechanism
Adenovirus infection in humans are generally caused by Adenoviruses types B, C, E and F.Although epidemiologic characteristics of the adenoviruses vary by type, all are transmitted by direct contact, fecal-oral transmission, and occasionally waterborne transmission. Some types are capable of establishing persistent asymptomatic infections in tonsils, adenoids, and intestines of infected hosts, and shedding can occur for months or years. Some adenoviruses (e.g., serotypes 1, 2, 5, and 6) have been shown to be endemic in parts of the world where they have been studied, and infection is usually acquired during childhood. Other types cause sporadic infection and occasional outbreaks; for example, epidemic keratoconjunctivitis is associated with adenovirus serotypes 8, 19, and 37. Epidemics of febrile disease with conjunctivitis are associated with waterborne transmission of some adenovirus types, often centering on inadequately chlorinated swimming pools and small lakes. ARD is most often associated with adenovirus types 4 and 7 in the United States. Enteric adenoviruses 40 and 41 cause gastroenteritis, usually in children.