Rubella is a Togavirus that is spherical, enveloped and single stranded RNA virus also known as German measles or the three-day measles.It is one of the TORCH syndrome.Most people are asymptomatic to Rubella virus.The virus manifest itself with rash.
The rashes may start around two weeks after exposure and last for a period of at three days.Rubella virus usually starts on the face then spreads to the rest of the body.
Epidemiology Rubella infection
Rubella virus occurs worldwide and mostly tends to peak during the spring in temperate countries. The vaccine of Rubella was introduced in 1969 but before then,widespread outbreaks usually occurred every 6–9 years in countries such as the United States and Europe with high occurrence among children age between 5-9 year old.The virus infection during pregnancy were estimated to have caused 30,000 stillbirths and 20,000 children to be born impaired or disabled but the introduction of vaccine has greatly reduced the occurrences of the infection.
mode of transmission of Rubella virus
Rubella virus infect only humans. Insects do not spread the rubella virus
- Rubella virus is usually spread through the air possibly via coughs of from infected people(Respiratory route).It replicates in the nasopharynx and lymph nodes.
- People are infectious during the week before and after the appearance of the rash because the virus is found in the blood 5 to 7 days after infection and spreads throughout the body.
- Babies with Congenital rubella syndrome (CRS) may also spread this virus for more than a year and Insects do not spread the disease.
- Because of its teratogenic properties, it is capable of crossing the placenta of the mother infecting the fetus where it stops cells from developing or destroys them.Note that once a person recovers from this infection,they become immune to future infections.
Incubation period and Infectivity of Rubella infection
- Mostly 14 to 21 days is the incubation period of this virus in the body with an average being 18 days.
- Rubella infectivity will drop when the rash disappears but the maximum time of infectivity always occurs before the appearance of rubella rash and at the time the rash is present
Signs and symptoms of Rubella virus
Rubella virus can affect anyone of any age and is generally a mild disease, rare in infants or those over the age of 40. Note that,he older the person is the more severe the symptoms are likely to occur.
- Appearance of rash mostly on the face which eventually spreads to the trunk and limbs and usually fades after three days reason why it is often referred to as three-day measles as stated above.
- Rubella rash is typically pink or light red in color.It causes itching and often lasts for about three days then disappears after a few days with no staining or peeling of the skin. When the rash clears up, the skin might shed in very small flakes where the rash covered it.
- Low grade fever
- swollen glands
- joint pains
- The swollen glands or lymph nodes which can persist for up to a week
Rubella in Children signs and symptoms
Symptoms normally last for two days which includes
- Rashes that begins on the face then spreads to the rest of the body.
- Low fever with temperature less than 38.3 °C (101 °F).
- Posterior cervical lymphadenopathy.
Some older children and adults will experience addition symptoms such as
- Swollen glands
- Coryza (cold-like symptoms) which may convert to pneumonia (direct viral pneumonia or bacterial pneumonia.
- Aching joints (especially in young women)
While sometime complicated symptoms such as
- Brain inflammation
- Ear infection (Otitis media)
Rubella in pregnancy
During pregnancy,Rubella occurrence mainly affect the foetus.There is a probability of up to 80% of pregnant women who contract Rubella to transmit it to the baby especially during the first trimester of pregnancy that is the first 3 months of pregnancy.
This rate of infection decreases When a pregnant woman becomes infected with Rubella in the second trimester of pregnancy ( 4th to 6th months of pregnancy).When Rubella infection occurs during the last three months of pregnancy (3rd trimester) there’s no ill-effects.
The ability of Rubella virus to affect the foetus and form congenital abnormalities, is referred to as Congenital rubella syndrome or Rubella Embryopathy which is characterized by the presence of a cardiac malformations affecting the fetus such as as
- Patent ductus arteriosus and ventricular septal defect
- eye lesions such as cataracts
- mental retardation
- microcephaly (small head)
- spina bifida
The effects of rubella on a fetus vary and not all fetuses affected may have the same abnormalities; the major tetrad comprises cataracts, heart defects (pulmonary artery hypoplasia or stenosis, persistent ductus arteriosus , tetralogy of Fallot, and ventricular septal defect), deafness and mental retardation. Rubella may cause fetal death in some cases.
In the Expanded rubella syndrome, there is manifestation of the congenital rubella syndrome with additional abnormalities such as hepatosplenomegaly which is the enlargement of the liver and spleen, interstitial pneumonia, myocarditis and metaphyseal bone lesions.
Laboratory Diagnosis of Rubella Virus
Immunoglobulin G (IgM) specific antibody body for Rubella virus are present recently infected people and can persist for over a year therefore a positive test result needs to be interpreted with caution.Characteristic rash, soft palate petechial lesions and the lymph nodes along with, or a short time after the presence of these antibodies can be used to confirms the diagnosis after running a proper and specific laboratory test such as :
- Rubella immune status tests carried out to know if one has been infected or not. These tests includes Hemagglutination inhibition (HI), Enzyme Immunoassay (EIA), or Latex Agglutination and is said to be reactive when Hemagglutination inhibition titers are 1:10 or greater
- Immunoglobulin M tests (IgM) are also done for babies in suspected congenital rubella (CSR) infection in order to differential or distinguish maternal antibodies from fetal antibodies.
- The viral genome can be detected in throat swabs (or oral fluid samples), urine and, in the case of intrauterine infection
Rubella Virus Treatment
There is actually no current drug of cure for Rubella.The body immune system antibodies are formed to fight the infection
Prevention of Rubella using Vaccine
This is mostly done by administering vaccine to children in order to enable the body develop antibodies that will fight the infection in case the baby or child get infected. This vaccine is given together with Mumps and Measles vaccines called Measles-Mumps-Rubella (MMR) Vaccine. Route of administration is subcutaneously 0.5 mL usually when the child is 12 to 15 months old.A booster dose is also recommended at 4 to 6 years of age.
Some complication of Rubella
- Cerebral palsy
- Spina bifida
- Thrombocytopenia (due to destruction of the platelets leading to petechiae)
- Congenital Cataract
- Microphthalmia (a small eye):
- Congenital heart diseases such as patent ductus arteriosus, atrial septa defect and ventricular septa defect.
- Neonatal jaundice
- Bell palsy
- Hearing loss
- Viral hepatitis
- Congenital glaucoma
- Pulmonary bacterial super-infection
- Females most often may develop Arthralgia following rubella disease