Transmission electron micrograph of<unk>  viruses The disease is caused by the<unk>  virus, in the genus Rubivirus from the family Matonaviridae, that is enveloped and has a single-stranded RNA genome. The virus is transmitted by the respiratory route and replicates in the nasopharynx and lymph nodes. The virus is found in the blood 5 to 7 days after infection and spreads throughout the body. The virus has teratogenic properties and is capable of crossing the placenta and infecting the fetus where it stops cells from developing or destroys them. During this incubation period, the patient is contagious typically for about one week before he/she develops a rash and for about one week thereafter. Increased susceptibility to infection might be inherited as there is some indication that HLA-A1 or factors surrounding A1 on extended haplotypes are involved in virus infection or non-resolution of the disease.
Rubella
Roseola
Ebola
Spanish flu
Polio
Hong Kong flu
Smallpox
Mumps