Rubella is a highly contagious viral disease, spread through contact with discharges from the nose and throat of an infected person. A person infected with the rubella virus is contagious for about seven days before any symptoms appear and continues to spread the disease for about four days after the appearance of symptoms. Rubella has an incubation period of 12–23 days.
Rubella is also called German measles or the three-day measles. This disease was once a common childhood illness, but its occurrence has been drastically reduced since vaccine against rubella became available in 1969. In the three decades following the introduction of the vaccine, reported rubella cases dropped 99.6%. Only 229 cases of rubella were reported in the United States in 1996. A recent study indicates, however, that the age group pattern of rubella is shifting. As of 2002, the number of cases reported in people aged 15 years or younger is dropping, while the number of cases in people between 25 and 45 is rising.
People of any age who have not been vaccinated or previously caught the disease can become infected. Having rubella once or being immunized against rubella normally gives lifetime immunity. This is why vaccination is so effective in reducing the number of rubella cases. The United States had a public health goal of eliminating all rubella within its borders by the year 2000; however, this goal was not attained because of new strains of the rubella virus entering the country from the Caribbean and Central America. The availability of molecular typing indicates that three separate strains of the virus caused localized outbreaks that were quickly contained. As of 2002, cases of rubella in the United States are more common among Hispanics than among Caucasians, Native Americans, or African Americans.
Women of childbearing age who do not have immunity against rubella should be the most concerned about infection. Rubella infection during the first three months of pregnancy can cause a woman to miscarry or cause the baby to be born with severe birth defects, including mental retardation and sensory impairments. In addition, recent studies indicate that infants exposed to rubella in utero (in the womb) are at increased risk of developing schizophrenia as adults.
Although it has been practically eradicated in the United States, rubella is still common in less developed countries because of poor immunization penetration, creating a risk to susceptible travelers. Some countries have chosen to target rubella vaccination to females only. As a result, outbreaks among foreign-born males have occurred on cruise ships and at summer camps in the United States. The United Kingdom is considering targeting immigrants of either sex from underdeveloped countries for rubella immunization following several cases of babies born with congenital rubella syndrome.
Kathleen Wright, Rebecca J. Frey PhD, The Gale Group Inc., Gale, Detroit,