Adenovirus

Classification:

Adenoviridae

Structure:

linear, dsDNA, icos., non env.

Diseases

Sites and Sources

Diagnostic Factors

Virulence Factors

Treatment and Prevention

Commentary

Adenoviruses infect epithelial cells that line the respiratory and enteric organs. This can lead to a variety of diseases in the respiratory tract, gastrointestinal tract, and eyes. The initial site of infection is usually the pharynx or the eye. Following local replication, viremia can spread the virus to other organs. This is more likely to occur in immunocompromised individuals. The particular disease is determined by the tissue tropism of the serotype of the infecting virus. Damage is caused by cell death in these organs. The virus can also become latent in lymphoid tissue such as adenoids or Peyers patches, and can be reactivated by immunosuppression. Adenoviruses were first isolated in 1953 in cultures of human adenoid cells. There are some 100 serotypes, of which at least 42 infect humans. They account for between 5% and 10% of all viral infections in humans, most of which occur in children. Most infections are of the gastrointestinal or respiratory tracts. Because some adenoviruses cause tumors in rodents, they have been extensively studied. No association between adenoviruses and human cancer has ever been found, but studies of the replication and mechanisms of tumor formation in rodents have led to the elucidation of many of the molecular-genetic mechanisms of eukaryotic cells. One of the more startling of these was the fact that eukaryotic mRNAs contain introns and undergo splicing in the formation of a mature message.