One of a group of viruses that produces upper respiratory disease. Viruses, unlike true organisms, are parasites that exist within cells of their host and derive their energy from the metabolism of the cells they infect.
Today there are 31 known human and 17 animal types of adenovirus, but illness is apparently caused by only 10 of these. Strains of nine types have caused a form of cancer in newborn hamsters. Adenoviruses were first isolated from the adenoids in 1953. The types that cause disease produce five different patterns of illness, all occurring in epidemics:
Acute Respiratory Disease (ARD) is primarily associated with military personnel: 15 to 20 percent of respiratory illness among military recruits is caused by adenoviruses, whereas only two percent of re- spiratory illnesses in the general population and six percent in children come from that source. ARD is ån acute illness with fever lasting about one week. The fever reaches its peak of 103 °F. or 104 °F on the second or third day and then drops. Cough, hoarseness, and sore throat are characteristic.
Febrile pharyngitis due to adenoviruses is usually a disease of civilians and resembles ARD. Usually it is accompanied by fever, and often by bronchitis in older children.
Pharyngoconjunctival fever is usually milder than ARD, but fever may be high for several days. A mild to moderate eye irritation
Adenovirus 7, a cause of pharyngitis, conjunctivitis (or “pink eye”), or pneumonia in infants, shown here in a human cell and magnified 38,000 times. Each black spot is a virus.
without discharge is its prime symptom. It often occurs in summer epidemics among school age children; primarily its frequent association with swimming pools may indicate that eye irritation by chlorine, sun, or water may help initiate the disorder. Eye symptoms may occur without pharyngitis.
Adenoviral pneumonia due to adenovirus infection is rare in civilian adults, but occurs frequently in military recruits as a secondary extension of ARD. In infants and children, the adenoviral pneumonia occurs sporadically in epidemics as a primary illness, and is fatal as much as 15 percent of the time.
Keratoconjunctivitis is an epidemic disease occurring in shipyard workers or spread by infected eye solutions. There is usually no fever, but a severe, acute conjunctivitis. The incubation period varies from 5 to 10 days.
There is no specific treatment for adenovirus infection beyond easing discomfort by use of aspirin, cough syrups, and antihistamines. Some vaccines are currently being tested for protection against specific strains of adenovirus infection. Antibiotics are ineffective unless bacterial complication occurs.
However, there are many treatable and some serious diseases whose early symptoms resemble those of adenovirus infection symptoms—infectious hepatitis and infectious mononucleosis, streptococcal sore throat, leptospirosis, and
influenza. For this reason, further signs of illness, persistent fatigue or fever,and local inflammations should be noted by the patient and reported to his doctor.