Measles : History

by CDC

(Page 4 of 4)

References to measles can be found as far back as the 7th century A.D. In fact, the disease was described by Rhazes in the 10th Century A.D. as "more dreaded than smallpox." But all that changed in 1963 when the measles vaccine was first licenced in the U.S.

Impact of the Measles Vaccine

Prior to 1963, almost everyone got measles; it was an expected life event. Each year in the U.S. there were approximately 3 to 4 million cases and an average of 450 deaths, with epidemic cycles every 2 to 3 years. More than half the population had measles by the time they were 6 years old, and 90 % had the disease by the time they were 15. This indicates that many more cases were occurring than were being reported. However, after the vaccine became available, the number of measles cases dropped by 98 % and the epidemic cycles drastically diminished.

Second Measles Vaccine Dose

It was discovered that, between 1985 and 1988, many measles cases had occurred in children who had been vaccinated. While there were far fewer measles cases among vaccinated children than among unvaccinated, the children who received only one dose were not always protected from the disease. This led to the recommendation of a second dose for children between the ages of 5 and 19 years of age to ensure protection for those who had not developed immunity from the first dose.

1989-1990 Measles Epidemic

A dramatic increase in measles cases occurred between 1989 and 1991. During those three years, 55,622 cases were reported Most of the cases occurred in children under 5 years of age, with the number of cases among unvaccinated Hispanic and African American populations being four to seven times higher than among non-Hispanic whites. This also marked the first time the number of measles cases for children under 5 years of age exceeded those for the 5 to 19 years old group.

During this period, 123 people died from measles-related illnesses - almost half were under 5 years old. Ninety percent of those who lost their lives had not been vaccinated. The 64 deaths in 1990 was the largest number that had been seen in almost 20 years.

Measles Outbreaks in Recent Years

Since 1993, the largest outbreaks of measles have occurred in populations that refuse vaccination, including communities in Utah and Nevada, and in Christian Scientist schools in Missouri and Illinois. Smaller outbreaks were reported in unvaccinated preschool populations, vaccinated school populations, among college students, and in adult communities, but these outbreaks were much smaller than those reported during 1989-1991. In recent years, outbreaks of measles have been small (less than 50 cases) and have chiefly involved high school and college students who are unvaccinated or have received only one dose of measles No large preschool-type outbreak has been reported since 1992.

Source of Today's Measles Cases

In March of 2000, a group of expert consultants convened by the CDC concluded that measles is no longer endemic in the U.S. Rather, all cases in the U.S. appear to be the result of importations, with limited domestic spread. This means that the only measles cases we see in the U.S. today have been brought in from other countries, usually Europe and Asia. Due to an aggressive measles vaccination program by the Pan American Health organization, measles incidence is now very low in Latin America and the Caribbean. Measles elimination from the Americas appears to be an achievable goal.

About the Author

www.cdc.gov
The Centers for Disease Control and Prevention (CDC) is one of the 13 major operating components of the Department of Health and Human Services (HHS), which is the principal agency in the United States government for protecting the health and safety of all Americans and for providing essential human services, especially for those people who are least able to help themselves.