The Danger of Rubella, the "Other" Measles

The large multi-state measles outbreak in the United States highlights the threat of reemergence of an infectious disease--even though a relatively small part of the population is susceptible to it.

The outbreak of this highly contagious, potentially fatal disease occurred when an infected visitor from another country reintroduced and transmitted the disease among the unvaccinated.

While some with up-to-date immunizations might get infected by measles (the small group that doesn’t develop immunity, the immunosuppressed and infants who are too young for vaccination), those who are at greatest risk have put their children in that position by refusing vaccination.

Birth Defects from Congenital Rubella Syndrome

Lack of universal immunization also poses a greater threat--one that could affect the children of today’s unvaccinated youth.

For a variety of reasons, there is no inoculation against measles alone. Rather, pharmaceutical manufacturers bundle the measles, mumps and rubella vaccines into one injection (commonly called MMR). Therefore, a lack of immunization to measles also means lack of immunization to mumps and rubella.

Mumps outbreaks have been even more common than measles. Mumps usually do not cause mortality, but can cause encephalitis and permanent sterility.

Those effects are serious, but there’s an even bigger problem with rubella (commonly called the German measles or three-day measles). A disease rarely seen in the US for the last 30 years, rubella causes a mild fever with a faint rash. Unlike its cousin measles, recovery from rubella is quick and uncomplicated. Furthermore, about half of those who get rubella don’t have symptoms.

But appearances can be deceiving. The real problem with rubella is its devastating effect on the fetus of nonimmune women infected duringpregnancy. Rubella causes a wide variety of severe congenital abnormalities, including prematurity, blindness, deafness, heart defects, developmental delays, hepatitis, blood abnormalities and others. The infection is so severe that the medical community has taken extraordinary measures to eliminate the horrific complications of an otherwise trivial infection.

All prenatal women are screened for rubella and get the MMR after the pregnancy is over if they are not immune. But pregnant women should not get the vaccine and pregnancy should be delayed for three months following immunization. This effort has been extremely successful and is a tribute to the success of universal vaccination. In the United States, congenital rubella syndrome has virtually disappeared with literally one or no cases reported annually.

Reversing Success?

In 2004, the Centers for Disease Control and Prevention announced that rubella had been eliminated from the United States. It is quite a success story, considering that the disease caused 20,000 disabled babies per year in the 1960s.

Now, very few pediatricians have even seen a case of rubella, let alone a case of congenital rubella syndrome. What used to be commonly feared among mothers--polio--is an unknown entity today. The success is based on herd immunity, which does not allow a re-introduction of the disease to spread. However, over the next 20 years, it is not hard to imagine a scenario where rubella and the congenital rubella syndrome reemerge as unvaccinated girls reach child-bearing age.

Complicating this scenario even further is that many women do not undergo prenatal testing until they learn they are pregnant. By then, it is too late to vaccinate for rubella, even if testing demonstrates no immunity. This could easily occur in women whose parents refused to vaccinate them as infants, resulting in a significant group of young girls who will be susceptible to rubella. In addition, a mother with a mild rubella infection may appear asymptomatic, causing the disease to be overlooked.

Regardless of how clinically mild rubella may be for the mother, it will be devastating to the fetus.

Just as a single case of measles from a foreign traveler caused the recent outbreak of measles, the same could happen with rubella. There will be no warning signs. Unlike measles, a rubella outbreak will be difficult to recognize until infants with severe abnormalities are born and diagnosed with congenital rubella syndrome.

The consequences could be shattering. Although it is nonexistent in the United States, rubella is still prevalent in many parts of the world that do not practice universal vaccination. Even in developed countries such as Japan, 15,000 cases of rubella and 43 cases of congenital rubella have been reported in recent years.

It is sad and ironic that parents would deny their children the safe, effective MMR vaccine for fear of autism when the association has been disproven, even while they increase the risk of severe rubella-related abnormalities in their grandchildren.

This is a tragedy waiting to happen--one we can easily prevent.

This post was written by Bruce Farber, MD, director of infectious diseases for the North Shore-LIJ Health System.

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