Virus Classification and Families

Parvoviruses have small, single-stranded DNA genomes with inverted terminal repeats (ITRs) at the ends.

Some dependoviruses can replicate without a helper virus, but others rely on adenoviruses for replication.

Parvovirus replication is limited to the S phase of the cell cycle because critical proteins are only available then.

Reoviruses were initially characterized as viruses found in respiratory and intestinal tracts, without apparent disease.

Picornaviruses have small, single-stranded RNA genomes (7-8 kb).

Influenza viruses that infect birds, some of which can infect humans and are highly pathogenic (harmful), causing severe respiratory disease and sometimes death.

A highly pathogenic avian influenza virus that caused a serious outbreak in poultry in Hong Kong in 1997 and spread to other Asian countries, Europe, and Africa later.

Viruses with minus-strand RNA genomes, often rod-shaped in plants or bullet-shaped in animals. They infect mammals, fish, plants, and insects.

A rhabdovirus with a wide host range, highly pathogenic in mammals. Symptoms are typically severe.

The spread of a virus from one human to another.