Rubella virus
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Rubella virus
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Rubella p. 166
cardiac defect association p. 304
cataracts p. 550
heart murmur with p. 296
rash p. 178
ToRCHeS infection p. 181
unvaccinated children p. 183
Lymphadenopathy
rubella p. 166, 181, 178
Cataracts p. 550
rubella p. 181
Congenital heart disease p. 302-304
rubella p. 181
Deafness
rubella p. 181
Blueberry muffin rash
rubella p. 166, 181
Polyarthralgias
rubella p. 181
Polyarthritis
rubella p. 181
Rashes
rubella p. 166, 178
Arthralgias
rubella p. 166, 181
Togaviruses
rubella as p. 164
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Rubella, the infection formerly known as “German Measles,'' is caused by the Rubella virus.
Thanks to vaccination, it’s a disease we see less and less, although because some groups are under-immunized, it’s still possible to see outbreaks.
The Rubella virus is part of the Togaviridae family.
Togaviruses are single-strand RNA viruses surrounded by an icosahedral capsid, which is a spherical protein shell made up of 20 equilateral triangular faces, all within a spherical outer lipid envelope.
They’re also positive sense RNA viruses, which means that their genetic material is actually mRNA, so it can be used right away by the host cell to make viral proteins.
Now, the Rubella virus is transmitted through respiratory droplets, which are released into the environment when you sneeze or cough on another person.
Within the nasopharynx mucous membrane, the virus binds to a specific receptor on the membrane of epithelial cells.
It’s then surrounded by a little section of cell membrane that pinches off to form an endosome, that’s brought into the cell.
The low pH in the endosome uncoats the viral RNA and the virus causes changes to the endosome.
Now, when the Rubella virus enters the cell it also rearranges some of the organelles, gathering the endoplasmic reticulum, golgi apparatus, and mitochondria around the endosome.
The result is a membrane-bound Viral Replication Complex where - like the name says - the virus replicates.
So, after the virus replicates, its structural proteins are synthesized using the rough endoplasmic reticulum and these proteins are then transported to the golgi apparatus to be assembled and surrounded by membrane, a process called viral budding.
The new virus copy eventually exits the cell by exocytosis and enters nearby lymphatic and blood vessels, travelling to lymph nodes where it will replicate once again.
From the lymph nodes, it enters blood vessels again, and spreads to various parts of the body, making its way into various bodily fluids like urine, cerebrospinal fluid, and synovial fluid of joints.
Finally, the Rubella virus has a cytopathic, or cell-damaging, effect, that’s linked to viral replication.
Summary
Rubella virus is a single-strand, positive-sense RNA virus of the Togaviruses family, which is known to cause rubella, sometimes referred to as German measles. The virus is spread through respiratory droplets and infects and replicates in mucous membrane cells of the nasopharynx, then does the same in lymph nodes, triggering apoptosis in infected cells. Infected children are often asymptomatic or might have mild symptoms like fever, lymphadenopathy, and a rash, whereas adults tend to show more serious symptoms and get sick longer. Complications of rubella are rare but may include arthritis, encephalitis, and thrombocytopenia. Treatment for Rubella is supportive and prevention involves a live attenuated vaccine.