PARAMYXOVIRUS - RUBELLA VIRUS
Definition
- Rubella virus is a member of the Paramyxoviridae family.
Morphology
- Rubella virus is a small, enveloped virus with a single-stranded RNA genome.
- It has a helical nucleocapsid with a diameter of 60-70 nm.
- The virus has a glycoprotein spike on its surface.
Clinical Features
- Rubella virus infection typically causes a mild, self-limiting illness.
- Symptoms include fever, sore throat, and a rash that starts on the face and spreads to the rest of the body.
- The rash usually lasts for 2-3 days.
- In adults, the infection is usually asymptomatic or mild.
Congenital Rubella Syndrome (CRS)
- CRS occurs when a pregnant woman infected with rubella virus passes the virus to her fetus.
- Symptoms of CRS include birth defects, such as heart defects, cataracts, and deafness.
- CRS can also cause miscarriage or stillbirth.
- The risk of CRS is highest during the first trimester of pregnancy.
Laboratory Diagnosis
- Diagnosis of rubella virus infection is confirmed by serological tests, such as ELISA or immunofluorescence.
- PCR (polymerase chain reaction) can also be used to detect the virus in clinical samples.
Pathogenesis → The virus enters the body through the respiratory tract. → The virus replicates in the respiratory tract and spreads to the lymphoid tissues. → The virus then spreads to the bloodstream and infects various organs, including the placenta during pregnancy. → The virus causes inflammation and damage to the infected tissues.
Life Cycle
- Attachment: The virus attaches to the host cell receptor.
- Penetration: The virus penetrates the host cell membrane.
- Uncoating: The virus releases its genetic material.
- Replication: The virus replicates its genetic material.
- Assembly: The virus assembles new viral particles.
- Release: The virus is released from the host cell.
Memory Trick
- "ARISE" - Attachment, Replication, Infection, Spread, Evasion, Release (A.R.I.S.E.)
Word Trick
- "Rubella" - "Rash, Ugly, Big, Loud, Epidemic, Lousy" (R.U.B.E.L.L.A.)