Rubella Virus

Virology

Rubella virus (RV) is the only member of the Rubivirus genus of the family Togaviridae. The viral particle is 60nm in diameter, and nucleocapsid is 33nm. The genome of the rubella virus is approximately a 10 Kb long, positive-sense single-stranded RNA, that codes for the two nonstructural and three structural proteins. Three structural proteins include the capsid protein (31 kDa) and the glycoproteins E1 (58 kDa) and E2 (42-47 kDa). The capsid protein interacts with the RNA genome and forms the nucleocapsid, which is surrounded by a lipid membrane upon which E1 and E2 are arranged. The E1 protein is responsible for viral hemagglutination and neutralization. The E2 protein can take two different forms depending on glycosylation (E2a or E2b), inducing differences in antigenicity. Two nonstructural proteins, p90 and p150, are involved with virus replication.

Fig.1 A plot of immune response to rubella virus infections (left) and a schematic diagram of rubella virus (right). (Dimech, 2016)

Congenital Rubella Syndrome

Congenital rubella syndrome (CRS) is an illness in an infant resulting from rubella virus infection from pregnancy. Maternal infection with rubella can have serious consequences for the developing fetus. During the first 11 weeks of gestation, there is a very high risk (90%) that the child will be born with CRS. Rubella infection during the first trimester of pregnancy can cause miscarriage, stillbirth, or the birth of a child with CRS. CRS can lead to deafness, cataract, and variety of other permanent manifestations including cardiac and neurological defects.

Epidemiology

• Rubella has a worldwide distribution except in countries where the disease has been eliminated.
• Epidemics occurred roughly every 6-9 years. It usually occurs in a seasonal pattern (i.e. in temperate zones during the late winter and spring).
• Humans are the only known hosts susceptible to rubella infection, making it a candidate for eradication. Infection is uncommon in preschool children but outbreaks involving school children and young adults were common.
• Rubella is only moderately contagious; it is acquired via inhalation of aerosols with the maximum infectivity occurring from 3 days before the onset of rash until 3 days after.

Symptoms

Rubella is not the same as measles which is called Rubeola which is a serious disease. The average incubation period for rubella is 14 days but can range from 12-23 days. In adolescents and adults, a short prodromal phase (1-5 days) occurs before the rash appears. In children, prodromal symptoms are rare, and a rash is usually the first manifestation. The prodrome consists of low-grade fever, malaise, and mild conjunctivitis. Other symptoms may include headache, anorexia, coryza, sore throat, and cough. Enlargement of the lymph nodes (lymphadenopathy) occurs from 5-10 days before the onset of the rash. At approximately 14-17 days after infection, a maculopapular rash (a pink skin rash of discrete spots) develops. The rash starts on the face and neck, progresses down the trunk to the extremities, and lasts about 3 days. The rash is much fainter than that seen in measles and is occasionally pruritic.

Prevention and Treatment

• Vaccine

There is a safe and effective vaccine to prevent rubella. The rubella vaccine is recommended for all children. The rubella vaccine is a live attenuated strain that has been in use for more than 40 years. A single dose gives more than 95% long-lasting immunity.

• Treatment

There is no specific treatment for rubella, but symptoms will normally pass within 7 to 10 days. If the rubella infection occurs in women pregnant, antibodies called hyperimmune globulin can fight off the infection. But it doesn't eliminate the possibility of the foetus developing CRS.

Anti-Rubeola Virus Products and Services

Having been committed to antibody development for decades of years, Creative Biolabs has devoted itself to the field of virology to provide various ViroAntibody products and services. Our anti-Rubella virus monoclonal antibody can be used to serve your research of Rubella virus. A full comprehensive suite of primary antibodies, secondary antibodies, and isotype controls are supplied to meet your needs. Please feel free to contact us.

Reference

1. Dimech, W.; et al. Standardization of assays that detect anti-rubella virus IgG antibodies. Clin Microbiol Rev. 2016, 29(1): 163-174.

All products and services are intended for Research Use Only, and NOT to be used in diagnostic or therapeutic procedures.