Rubella, commonly known as German measles, is a disease caused by Rubella virus. The name is derived from the Latin, meaning little red. Rubella is also known as German measles because the disease was first described by German physicians in the mid-eighteenth century. This disease is often mild and attacks often pass unnoticed. The disease can last one to five days. Children recover more quickly than adults. Infection of the mother by Rubella virus during pregnancy can be serious; if the mother is infected within the first 20 weeks of pregnancy, the child may be born with congenital rubella syndrome (CRS), which entails a range of serious incurable illnesses. Spontaneous abortion occurs in up to 20% of cases.
Rubella is a common childhood infection usually with minimal systemic upset although transient arthropathy may occur in adults. Serious complications are very rare. Apart from the effects of transplacental infection on the developing foetus, rubella is a relatively trivial infection.
Acquired, (i.e. not congenital), rubella is transmitted via airborne droplet emission from the upper respiratory tract of active cases. The virus may also be present in the urine, faeces and on the skin. There is no carrier state: the reservoir exists entirely in active human cases. The disease has an incubation period of 2 to 3 weeks.
In most people the virus is rapidly eliminated. However, it may persist for some months post partum in infants surviving the CRS. These children are a significant source of infection to other infants and, more importantly, to pregnant female contacts.
Rubella can affect anyone of any age and is generally a mild disease, rare in infants or those over the age of 40. The older the person is the more severe the symptoms are likely to be. Up to one-third of older girls or women experience joint pain or arthritic type symptoms with rubella. The virus is contracted through the respiratory tract and has an incubation period of 2 to 3 weeks. During this incubation period, the carrier is contagious but may show no symptoms.
The disease is caused by Rubella virus, a togavirus 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. It is capable of crossing the placenta and infecting the fetus where it stops cells from developing or destroys them.
Increased susceptibility to infection might be inherited as there is some indication that HLA-A1 or factors surrounding A1 on extended haplotypes are be involved in virus infection or non-resolution of the disease.
The vaccine is now given as part of the MMR vaccine. The WHO recommends the first dose is given at 12 to 18 months of age with a second dose at 36 months. Pregnant women are usually tested for immunity to rubella early on. Women found to be susceptible are not vaccinated until after the baby is born because the vaccine contains live virus.
The immunization program has been quite successful. Cuba declared the disease eliminated in the 1990s, and in 2004 the Centers for Disease Control and Prevention announced that both the congenital and acquired forms of rubella had been eliminated from the United States.
During the epidemic in the US between 1962-1965, Rubella virus infections during pregnancy were estimated to have caused 30,000 still births and 20,000 children to be born impaired or disabled as a result of CRS. Universal immunisation producing a high level of herd immunity is important in the control of epidemics of rubella.
In 1814, George de Maton first suggested that it be considered a disease distinct from both measles and scarlet fever. All these physicians were German, and the disease was known as Rötheln (from the German name Röteln), hence the common name of "German measles". Henry Veale, an English Royal Artillery surgeon, described an outbreak in India. He coined the name "rubella" (from the Latin, meaning "little red") in 1866.
It was formally recognised as an individual entity in 1881, at the International Congress of Medicine in London. In 1914, Alfred Fabian Hess theorised that rubella was caused by a virus, based on work with monkeys. In 1938, Hiro and Tosaka confirmed this by passing the disease to children using filtered nasal washings from acute cases.
In 1940, there was a widespread epidemic of rubella in Australia. Subsequently, ophthalmologist Norman McAllister Gregg found 78 cases of congenital cataracts in infants and 68 of them were born to mothers who had caught rubella in early pregnancy. Gregg published an account, Congenital Cataract Following German Measles in the Mother, in 1941. He described a variety of problems now known as congenital rubella syndrome (CRS) and noticed that the earlier the mother was infected, the worse the damage was. The virus was isolated in tissue culture in 1962 by two separate groups led by physicians Parkman and Weller.
There was a pandemic of rubella between 1962 and 1965, starting in Europe and spreading to the United States. In the years 1964-65, the United States had an estimated 12.5 million rubella cases. This led to 11,000 miscarriages or therapeutic abortions and 20,000 cases of congenital rubella syndrome. Of these, 2,100 died as neonates, 12,000 were deaf, 3,580 were blind and 1,800 were mentally retarded. In New York alone, CRS affected 1% of all births
In 1969 a live attenuated virus vaccine was licensed. In the early 1970s, a triple vaccine containing attenuated measles, mumps and rubella (MMR) viruses was introduced.