Immunization Issues

Rubella Parties

Updated: Abril 14, 2004

Rubella in childhood is usually a mild illness and its major cause of harm is when infection occurs during pregnancy, especially during the early months of pregnancy.

The risk of women contracting rubella infection has been greatly reduced in the United States by the universal immunization of young children and women with rubella vaccine.

However, some people, confused about the possible risks of the measles-mumps-rubella (MMR) vaccine, have opted to not vaccinate their children against those diseases. Instead, some have sought to expose them in gatherings with other children that they believe have rubella as a way to protect their daughters before their childbearing years.

Unfortunately the child that is thought to have rubella may not have it. In fact, rubella is impossible to distinguish from many other common infections that produce a rash without special laboratory tests. Indeed, experienced physicians can be incorrect in their diagnosis of rubella when lacking those tests—sometimes calling other illnesses with a rash “rubella” and sometimes not recognizing rubella at all. Thus children who are thought to have rubella at a “rubella party” may not really have rubella. Some of these infections may cause serious risks to health.

If the “host” at such a party truly has rubella, not all children will become infected and thus will remain susceptible. Although rubella like measles is caused by a virus that is transmitted from person to person in mucus droplets coughed or sneezed into the environment, rubella doesn’t spread as effectively as measles in this type of setting.

Children infected with rubella at the “party” may or may not develop a rash, so there is no way to know which children have become immune without laboratory testing. This is because rubella usually is a mild illness; about half of infected persons will have no symptoms.

Anyone infected with rubella at the “party” becomes a hazard in the community for the unborn fetuses of women who may be susceptible to rubella and who are pregnant. Thus not only may the child who gets rubella not have symptoms they may be contagious for 3 to 4 weeks.

When rubella symptoms occur, they may include low-grade fever and swollen lymph nodes in the back of the neck followed by a generalized rash.

Complications of rubella are uncommon in children but may include joint pain, a temporary decrease in platelets, and encephalitis (inflammation of the brain). Temporary arthritis may also occur, particularly in adolescents and adult women.

So why is rubella a problem? Rubella in expectant women often leads to congenital rubella syndrome (CRS) in their fetuses. This is a devastating disease characterized by deafness, mental retardation, cataracts and other eye defects, heart defects, and diseases of the liver and spleen that may result in a low platelet count with bleeding under the skin.

The incidence and severity of congenital defects are greater if infection occurs during the first month of gestation. Up to 85% of expectant mothers infected in the first trimester will have a miscarriage, fetal death (stillbirth), or a baby with CRS.

The World Health Organization estimated that, in 1999, 110,000 infants were born with CRS worldwide. Although most CRS occurs in developing countries, it also continues to occur in the U.S., mostly among the infants of unimmunized women.

The first vaccines for rubella were licensed in 1969. Today rubella vaccine is generally given in combination with measles and mumps vaccines (MMR).

Before a vaccine was available, there was a rubella outbreak in the U.S. (1963 to 1964), during which it is estimated that about 12 million people developed the infection. Because some of those infected were expectant mothers, 11,000 fetuses died and 20,000 babies were born with permanent disabilities as a result of exposure to the virus during pregnancy. The number of cases of rubella fell very sharply once the rubella vaccine was licensed in 1969; today there are fewer than 10 cases of congenital rubella syndrome in the U.S. each year.

Persons exposed to infants with congenital rubella syndrome, particularly post-pubertal women for whom rubella immunity is critical, should be aware that infants with CRS may shed rubella virus for at least one year.

Researchers estimate that about one in every 22,000 MMR vaccinations could result in a child developing a temporary bleeding disorder called idiopathic thrombocytopenic purpura (ITP). ITP following MMR immunization is rarely dangerous — generally much less serious than measles, mumps, or rubella — and is easily treated. A recent study found that children who had ITP from other causes who then later received the MMR vaccine had no vaccine-associated recurrences. ITP can also occur as a result of rubella infection.

Risks of Rubella vs. Risks of the Rubella Vaccine

Risks of Rubella Parties

  • Rubella generally is not a serious disease in children but is caused by a contagious virus, which spreads when people touch or breathe in infectious droplets passed by coughing and sneezing.
  • Rubella causes spontaneous abortions in many pregnant women and severe birth defects in many of those that are subsequently born.
  • If the “party” results in the child becoming infected the child may have no symptoms but can spread the virus in the community to women who are pregnant.
  • The index case (the person used to expose the other children) may not have rubella.
  • The “rubella party” may not result in the child becoming immune to rubella.
  • The “party may result in an exposure to a more serious disease.
  • Complications of rubella are not common, but tend to occur more often in adults than in children. For example, arthralgia (joint pain) or arthritis (joint redness or swelling) may occur in up to 70% of adult women who contract rubella, but is rare in children and adult males. Fingers, wrists, and knees are often affected. Joint symptoms tend to occur about the same time or shortly after appearance of the rash and may last for up to 1 month; chronic arthritis is rare.
  • Encephalitis (brain swelling) is uncommon in children but can occur in one in 6,000 adults (especially in women).
  • Bleeding in the skin may occur in approximately 1 per 3,000 cases, occurring more often in children than in adults due to low platelets.
  • Gastrointestinal, cerebral, or intrarenal bleeding may occur uncommonly.
  • Additional complications include inflammation of the testis, neuritis, and a rare late syndrome of progressive panencephalitis.
  • Congenital infection (infection of the fetus) with rubella virus can affect virtually all organ systems, leading to miscarriage or severe consequences including impaired vision, hearing and mental retardation.

Risks of the Vaccine

  • MMR is an attenuated (weakened) live virus vaccine. It prevents measles, mumps and rubella.
  • Nearly all children who get the MMR vaccine (more than 80%) will have no side effects.
  • Most children who have a side effect will have only a mild reaction, such as soreness, redness or swelling where the shot was given, mild rash, mild to moderate fever, swelling of the lymph glands, and temporary pain, stiffness, or temporary swelling in the joints.
  • In about 5% to 15% of children given MMR, a fever in excess of 103 degrees F may occur—usually beginning about 7 to 12 days after they receive the vaccine.
  • Joint pain with or without redness or swelling following rubella immunization only occurs in those who are susceptible. Joint symptoms are uncommon in children and men. About 25% of women have joint pain and about 10% may have temporary (1 day to 3 weeks) arthritis (redness and swelling) 1-3 weeks after the vaccination.
  • In rare cases (about 3 children out of 10,000 given MMR, or 0.03% of recipients) a moderate reaction such as seizure related to high fever may occur. In rare cases (about 1 child out of 30,000 given MMR) develop temporary low platelet count, which can cause bleeding.
  • In extremely rare cases (less than 1 child out of 1,000,000 given MMR), children have a serious reaction, such as lowered consciousness, coma, or hypersensitivity (anaphylaxis)—swelling inside the mouth, difficulty breathing, low blood pressure, and rarely, shock.