Rubella is a contagious viral infection best known by its distinctive red rash. It's also called German measles or three-day measles. While this infection may cause mild symptoms or even no symptoms in most people, it can cause serious problems for unborn babies whose mothers become infected during pregnancy.

Rubella isn't the same as measles, but the two illnesses share some symptoms, including the red rash. Rubella is caused by a different virus than measles, and rubella isn't as infectious or as severe as measles.

The measles-mumps-rubella (MMR) vaccine is highly effective in preventing rubella.

In many countries, rubella infection is rare or even nonexistent. However, because the vaccine isn't used everywhere, the virus still causes serious problems for babies whose mothers are infected during pregnancy.

The signs and symptoms of rubella are often difficult to notice, especially in children. Signs and symptoms generally appear between two and three weeks after exposure to the virus. They usually last about one to five days and may include:

• Mild fever of 102 F (38.9 C) or lower
• Headache
• Stuffy or runny nose
• Inflamed, red eyes
• Enlarged, tender lymph nodes at the base of the skull, the back of the neck and behind the ears
• A fine, pink rash that begins on the face and quickly spreads to the trunk and then the arms and legs, before disappearing in the same sequence
• Aching joints, especially in young women

When to see a doctor

Contact your doctor if you think you or your child may have been exposed to rubella or if you have the signs or symptoms listed above.

If you're considering getting pregnant, check your vaccination record to make sure you've received your MMR vaccine. If you're pregnant and you develop rubella, especially during your first trimester, the virus can cause death or serious birth defects in the developing fetus. Rubella during pregnancy is the most common cause of congenital deafness. It's best to be protected against rubella before pregnancy.

If you're pregnant, you'll likely undergo a routine screening for immunity to rubella. But if you've never received the vaccine and you think you might have been exposed to rubella, contact your doctor immediately. A blood test might confirm that you're already immune.

Rubella is caused by a virus that's passed from person to person. It can spread when an infected person coughs or sneezes. It can also spread by direct contact with an infected person's respiratory secretions, such as mucus. It can also be passed on from pregnant women to their unborn children via the bloodstream.

A person who has been infected with the virus that causes rubella is contagious for one to two weeks before the onset of the rash until about one or two weeks after the rash disappears. An infected person can spread the illness before the person realizes he or she has it.

Rubella is rare in many countries because most children receive a vaccination against the infection at an early age. In some parts of the world, the virus is still active. This is something to consider before going abroad, especially if you're pregnant.

Rubella is a mild infection. Once you've had the disease, you're usually permanently immune. Some women who have had rubella experience arthritis in the fingers, wrists and knees, which generally lasts for about one month. In rare cases, rubella can cause an ear infection or inflammation of the brain.

However, if you're pregnant when you contract rubella, the consequences for your unborn child may be severe, and in some cases, fatal. Up to 80% of infants born to mothers who had rubella during the first 12 weeks of pregnancy develop congenital rubella syndrome. This syndrome can cause one or more problems, including:

• Growth delays
• Cataracts
• Deafness
• Congenital heart defects
• Defects in other organs
• Intellectual disabilities

The highest risk to the fetus is during the first trimester, but exposure later in pregnancy also is dangerous.

The rubella vaccine is usually given as a combined measles-mumps-rubella (MMR) vaccine. Doctors recommend that children receive the MMR vaccine between 12 and 15 months of age, and again between 4 and 6 years of age — before entering school. It's particularly important that girls receive the vaccine to prevent rubella during future pregnancies.

Babies born to women who have received the vaccine or who are already immune are usually protected from rubella for six to eight months after birth. If a child requires protection from rubella before 12 months of age — for example, for certain foreign travel — the vaccine can be given as early as 6 months of age. But children who are vaccinated early still need to be vaccinated at the recommended ages later.

Widespread concerns have been raised about a possible link between the MMR vaccine and autism. However, extensive reports from the American Academy of Pediatrics, the National Academy of Medicine and the Centers for Disease Control and Prevention conclude that there is no scientifically proven link between the MMR vaccine and autism. There is also no scientific benefit to separating the vaccines.

These organizations note that autism is often identified in toddlers between the ages of 18 and 30 months, which is about the time children are given their first MMR vaccine. But this coincidence in timing typically shouldn't be mistaken for a cause-and-effect relationship.

Do you need the MMR vaccine?

You don't need a vaccine if you:

• Had two doses of the MMR vaccine after 12 months of age.
• Have blood tests that indicate you're immune to measles, mumps and rubella.
• Were born before 1957. Women born before 1957 don't need a vaccine if they already had the rubella vaccine or if they have a positive rubella immunity test.

You typically should get a vaccine if you don't fit the criteria listed above and you:

• Are a nonpregnant woman of childbearing age
• Attend college, trade school or postsecondary school
• Work in a hospital, medical facility, child care center or school
• Plan to travel overseas or take a cruise

The vaccine is not recommended for:

• Pregnant women or women who plan to get pregnant within the next four weeks
• People who have had a life-threatening allergic reaction to gelatin, the antibiotic neomycin or a previous dose of MMR vaccine

If you have cancer, a blood disorder or another disease, or you take medication that affects your immune system, talk to your doctor before getting an MMR vaccine.

If you've been exposed to the virus that causes rubella, you can help keep friends, family and co-workers safe by telling them about your diagnosis. If your child has rubella, let the school or child care provider know.

Side effects of the vaccine

Most people experience no side effects from the vaccine. About 15% of people develop a fever between seven and 12 days after the vaccination, and about 5% of people develop a mild rash. Some teens and adult women experience temporary joint pain or stiffness after receiving the vaccine. Fewer than 1 out of 1 million doses causes a serious allergic reaction.

The rubella rash can look like many other viral rashes. So doctors usually confirm rubella with the help of laboratory tests. You may have a virus culture or a blood test, which can detect the presence of different types of rubella antibodies in your blood. These antibodies indicate whether you've had a recent or past infection or a rubella vaccine.

No treatment will shorten the course of rubella infection, and symptoms don't usually need to be treated because they're often mild. However, doctors often recommend isolation from others — especially pregnant women — during the infectious period.

If you contract rubella while you're pregnant, discuss the risks to your baby with your doctor. If you wish to continue your pregnancy, you may be given antibodies called hyperimmune globulin that can fight off the infection. This can reduce your symptoms, but doesn't eliminate the possibility of your baby developing congenital rubella syndrome.

Support of an infant born with congenital rubella syndrome varies depending on the extent of the infant's problems. Children who have multiple complications may require early treatment from a team of specialists.

Simple self-care measures are required when a child or adult is infected with the virus that causes rubella, such as:

• Bed rest
• Acetaminophen (Tylenol, others) for relief from fever and aches

As you prepare for your appointment, it's a good idea to write down any questions you have. Your doctor is likely to ask you a number of questions as well. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:

• Have you been vaccinated for rubella?
• How long have you had signs or symptoms, such as a rash or aching joints?
• Have you been exposed to anyone with rubella?
• Have you traveled to other countries in recent weeks? Which countries?
• Does anything seem to improve your symptoms?
• Does anything seem to worsen your symptoms?

When you check in for the appointment, be sure to tell the check-in desk that you suspect an infectious disease. The person may choose to give you a face mask or show you to your room immediately.