Viral disease | |
---|---|
Other names | Viral infection |
Transmission electron micrograph of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virions | |
Specialty | Infectious disease |
A viral disease (or viral infection) occurs when an organism's body is invaded by pathogenic viruses, and infectious virus particles (virions) attach to and enter susceptible cells. [1]
Examples are the common cold, gastroenteritis and pneumonia. [2]
Basic structural characteristics, such as genome type, virion shape and replication site, generally share the same features among virus species within the same family.[ citation needed]
Human-infecting virus families offer rules that may assist physicians and medical microbiologists/ virologists.[ citation needed]
As a general rule, DNA viruses replicate within the cell nucleus while RNA viruses replicate within the cytoplasm. Exceptions are known to this rule: poxviruses replicate within the cytoplasm and orthomyxoviruses and hepatitis D virus (RNA viruses) replicate within the nucleus.[ citation needed]
This group of analysts defined multiple categories of virus. Groups:[ citation needed]
The clinical characteristics of viruses may differ substantially among species within the same family: