Rubella, also known as German measles or three-day measles, is a viral infection that typically causes mild symptoms in most people but can have devastating consequences for unborn babies if a pregnant woman becomes infected.

Understanding Rubella

Rubella is a contagious illness caused by the rubella virus, also called RuV. Despite its mild nature in most people, this infection has earned serious attention from public health officials worldwide because of its potential to cause severe birth defects. The disease spreads easily from person to person, though it is not as contagious as measles, even though both illnesses share some similar symptoms like a rash.^[1]

The name “German measles” can be confusing because rubella is not the same disease as measles. Both are caused by completely different viruses and have different levels of severity. While measles tends to be more serious and spreads more easily, rubella poses its greatest threat to developing babies in the womb rather than to the infected person.^[2]

Many people infected with rubella may not even realize they have it. Research shows that between 25% and 50% of people who get rubella have no symptoms at all, yet they can still spread the virus to others. This hidden transmission makes preventing the spread of rubella particularly challenging and highlights why vaccination programs are so important.^[4]

Epidemiology: Who Gets Rubella and Where

The pattern of rubella infection has changed dramatically in countries with strong vaccination programs. In the United States, rubella was officially eliminated in 2004, meaning it no longer continuously spreads within the country. However, elimination does not mean the disease has disappeared entirely. Travelers can still bring rubella into the country from other parts of the world where the virus continues to circulate.^[2]

Globally, there are approximately 26,000 cases of rubella reported each year, though the true number may be higher because many infections go undetected. The disease remains most common in Asia, Africa, and the Middle East, where vaccination coverage may be lower. In the United States, only a few cases are diagnosed each year, usually linked to international travel.^[2]

Before the rubella vaccine became available in 1969, the disease was common, especially among children. Following widespread vaccination, the number of cases dropped dramatically. Today, adults account for an increasing proportion of the few cases that still occur in the United States. These cases often involve people who remain unvaccinated for religious or personal reasons, or foreign-born individuals who come from areas where rubella vaccination is not routine.^[5]

The World Health Organization announced in October 2018 that Australia had eliminated rubella, joining other countries with successful vaccination programs. Despite these achievements, an estimated 17,865 cases of rubella occurred worldwide in 2022 across 78 countries, reminding us that global vigilance remains necessary.^[9]

Causes and Transmission

Rubella is caused by the rubella virus, a small infectious agent that contains genetic material in the form of RNA. Like all viruses, the rubella virus cannot reproduce on its own and must invade human cells to make copies of itself. Once inside the body, the virus uses the cell’s own machinery to create more viral particles, which then spread to infect other cells.^[2]

The rubella virus spreads primarily through respiratory droplets. When an infected person coughs, sneezes, or even talks, tiny droplets containing the virus are released into the air. Other people can breathe in these droplets and become infected. The virus can also spread through direct contact with nasal or throat secretions from an infected person, or by touching surfaces contaminated with these secretions and then touching your eyes, nose, or mouth before washing your hands.^[7]

One of the most concerning aspects of rubella transmission is that infected people can spread the virus before they know they are sick. A person with rubella is contagious for about one week before the rash appears and remains contagious for at least four days after the rash starts. This means someone can unknowingly infect many others during this infectious period.^[13]

Pregnant women who become infected with rubella can pass the virus to their developing baby through the bloodstream. This is called vertical transmission and represents the most serious consequence of rubella infection. Babies born with rubella infection can shed the virus in their nose, throat secretions, and urine for months or even years, making them a long-term source of infection to others.^[4]

Unlike some infectious diseases that can spread through insect bites, rubella only spreads directly between humans. Insects do not carry or transmit the rubella virus. Once a person recovers from rubella, they typically develop lifelong immunity and will not get the disease again.^[6]

Risk Factors

Anyone who has not been vaccinated against rubella or has not had the disease before is at risk of getting rubella. The greatest risk exists in areas where vaccination coverage is low or in communities where people choose not to vaccinate for personal or religious reasons. International travelers who visit countries where rubella is still common face increased risk, especially if they are not immune.^[5]

Pregnant women who are not immune to rubella face the most serious risk, not for themselves but for their developing babies. When a woman gets rubella during pregnancy, especially in the first trimester, her unborn baby faces a very high chance of developing serious birth defects or dying. Medical experts estimate that if a woman contracts rubella early in pregnancy, she has a 90% chance of passing the virus to her fetus.^[9]

The timing of infection during pregnancy greatly affects the severity of consequences. The risk of serious birth defects is highest when infection occurs in the first eight to ten weeks of pregnancy, potentially affecting up to 90% of babies. Multiple defects are common during this period. If infection occurs around 16 weeks of pregnancy, the risk drops to about 10% to 20%, and defects are rare after 20 weeks of pregnancy.^[5]

Healthcare workers and childcare staff who are not immune to rubella face occupational risk because they may encounter infected individuals. These professionals should have their immunity assessed through blood tests and receive vaccination if they are not already protected. This protects not only the workers themselves but also the vulnerable populations they serve, including pregnant women and infants.^[5]

Symptoms and Clinical Presentation

The symptoms of rubella are often mild, and many people may not notice they are sick. When symptoms do occur, they usually appear between two and three weeks after exposure to the virus. This period between infection and the appearance of symptoms is called the incubation period and typically ranges from 14 to 17 days, though it can extend from 12 to 23 days.^[7]

The most recognizable symptom of rubella is a distinctive rash. In young children, the rash is often the first and sometimes only symptom they develop. The rash typically begins on the face, particularly around the forehead and hairline, and then spreads downward to the neck, chest, and eventually the entire body. The rash appears as small, pink or red spots that may be flat or slightly raised. On white skin, the rash appears pink or red, but it can be harder to see on brown or black skin, where it might be more noticeable by touch, feeling rough or bumpy.^[8]

The rubella rash usually lasts about three days, which is why the disease is sometimes called “three-day measles.” Unlike some other rashes, it typically does not itch very much, though some people may experience itching. The rash disappears in the same order it appeared, clearing first from the face and last from the legs and feet.^[1]

Before the rash appears, especially in older children and adults, other symptoms may develop. These can include a mild fever, usually no higher than 102 degrees Fahrenheit (38.9 degrees Celsius). People may experience headache, stuffy or runny nose, and red, itchy eyes similar to conjunctivitis (inflammation of the eye surface). A sore throat and general feeling of being unwell, called malaise, are also common.^[1]

One characteristic feature of rubella is swollen lymph nodes, particularly those at the base of the skull, at the back of the neck, and behind the ears. These swollen glands may be tender to touch and often appear before the rash develops. They can remain swollen for several weeks after other symptoms have disappeared.^[7]

Joint pain is another symptom of rubella, though it occurs more commonly in adults than in children. Women are especially likely to experience arthralgia (joint pain) or arthritis (joint inflammation), often affecting the fingers, wrists, and knees. Up to 70% of adult women with rubella may develop joint symptoms. These symptoms can be quite uncomfortable but typically resolve within a month after the rash appears.^[2]

Prevention Strategies

Vaccination represents the most effective way to prevent rubella. The rubella vaccine is typically given as part of a combination vaccine called MMR, which protects against measles, mumps, and rubella. Some formulations also include protection against varicella (chickenpox) and are called MMRV. The vaccine is safe, highly effective, and provides lifelong protection against rubella in most people.^[1]

A single dose of the rubella-containing vaccine is about 97% effective at preventing rubella infection. The standard vaccination schedule recommends that children receive two doses of MMR vaccine. The first dose is typically given between 12 and 15 months of age, and the second dose is usually administered before school entry, around 4 to 6 years of age. Getting both doses provides even stronger, longer-lasting protection.^[13]

Adults who were born on or after January 1, 1957, and do not have evidence of immunity to rubella should also receive the MMR vaccine. Evidence of immunity includes laboratory confirmation of antibodies, documentation of vaccination, or proof of having had rubella disease in the past. However, being born before 1957 is not considered acceptable evidence of immunity for women who could become pregnant. These women should have their immunity checked through blood testing and receive vaccination if needed.^[5]

Healthcare workers, childcare staff, and anyone who works with vulnerable populations should ensure they are immune to rubella. If immunity cannot be verified, vaccination should be provided. This is particularly important because these professionals may encounter infected individuals and could spread rubella to pregnant women or other susceptible people.^[5]

For people who have been exposed to rubella, prevention options are limited. The rubella vaccine does not prevent infection if given after exposure to the virus. Pregnant women who have been exposed to rubella and do not have immunity may be offered immunoglobulin (IG), a preparation containing antibodies. However, IG does not reliably prevent rubella infection or completely eliminate the risk of birth defects, though it may reduce the severity of symptoms and lower the chance of problems for the baby.^[10]

Simple hygiene measures can help reduce the spread of rubella. People with rubella should stay home from work, school, or childcare for at least five days after the rash appears. They should practice good respiratory hygiene by covering coughs and sneezes with tissues or their elbow, disposing of used tissues promptly, and washing their hands frequently with soap and water. People with rubella should avoid close contact with pregnant women and anyone who may not be immune.^[8]

Pathophysiology: What Happens in the Body

When the rubella virus enters the body through the respiratory tract, it begins reproducing in the tissues of the upper respiratory system and in nearby lymph nodes. From these initial sites of infection, the virus spreads throughout the body via the bloodstream in a process called viremia. This widespread distribution of virus typically occurs about five to seven days after initial infection.^[4]

Once the virus has spread throughout the body, the immune system recognizes it as a foreign invader and mounts a response. The body produces specific proteins called antibodies that are designed to recognize and neutralize the rubella virus. This immune response is what causes many of the symptoms of rubella, including the fever and rash. The rash appears as blood vessels near the skin surface dilate in response to immune system activity.^[4]

The characteristic swelling of lymph nodes occurs because these structures are working overtime to produce immune cells and antibodies. Lymph nodes are part of the body’s defense system and filter fluid from tissues to trap and destroy infectious agents. When actively fighting an infection, lymph nodes enlarge and may become tender. In rubella, the lymph nodes behind the ears and at the back of the neck are particularly affected because they drain the areas where the virus initially multiplies.^[1]

Joint pain and arthritis in rubella result from immune complexes—combinations of antibodies and viral particles—being deposited in joint tissues. These immune complexes trigger inflammation, causing pain and swelling. This reaction is more common in adult women, possibly due to hormonal factors that influence immune responses. The joint symptoms usually resolve as the immune system clears the infection, though they can persist for several weeks.^[5]

In pregnant women, the rubella virus can cross the placenta (the organ that connects mother and baby and provides nutrients). Once in the fetal circulation, the virus can infect developing tissues. The virus has a particular ability to interfere with normal cell division and development. During the first trimester, when organs and body systems are forming, this interference can result in severe malformations. The virus may also damage the placenta itself, affecting the baby’s growth and nutrition.^[4]

Rubella infection during pregnancy can affect almost every developing organ system. The virus can damage cells in the developing eyes, leading to cataracts (clouding of the lens) or other vision problems. It can interfere with the formation of the inner ear structures, causing permanent deafness. Heart defects occur when the virus disrupts the normal development of cardiac structures. Neurological problems result from viral damage to the developing brain. The earlier in pregnancy the infection occurs, the more severe and widespread the damage tends to be because more organ systems are in critical developmental stages.^[2]