WASHINGTON -- Smallpox was the first, in 1971. Then polio, in 1994. Wednesday, the Pan American Health Organization said two more diseases had been eradicated from the Americas: rubella and the similar congenital rubella syndrome.
Rubella, a virus also known as German measles, causes mild symptoms in adults and children, but severe birth defects and fetal death during early pregnancy. It affected 15,000 to 20,000 people a year in North America, Central America and South America prior to widespread vaccination, Dr. Cuauhtemoc Ruiz, Pan American Health Organization immunization unit chief, said at a news conference. A mother infected with rubella in early pregnancy can have a child born with congenital rubella syndrome.
Rubella was effectively eradicated from the United States around 2002, thanks to mass vaccination and public education. In 2009, Argentina experienced the Americas' last endemic cases of rubella, and Brazil had the final outbreak of congenital rubella syndrome. Public health experts consider a disease eradicated from a region once no endemic cases have been reported for at least three years.
If history is a guide, erasing rubella and congenital rubella syndrome from the Americas suggests the diseases will soon be eradicated from the planet.
The Americas was the first of the World Health Organization's six designated regions to eradicate smallpox. About a decade later, in 1980, the disease was eradicated worldwide. Polio followed a similar pattern, although a few hundred endemic cases are reported annually in Afghanistan, Nigeria, and Pakistan, so the disease isn't yet officially eradicated.
Replicating that success with rubella and congenital rubella syndrome will prove formidable, given the approximately 120,000 cases a year worldwide.
Dr. Susan Reef, a rubella expert at the U.S. Centers for Disease Control, said only two of the six WHO global regions, Europe and the Americas, have goals to eliminate rubella. "We need the four other regions to establish targeted elimination goals," she said. "So I can tell you it will not be before 2020" that the disease is eradicated globally.
Ruiz said the next goal was to eliminate rubella in the European region by the end of 2015, and in the Southeast Asia region by 2020. The other three regions -- African, Eastern Mediterranean, and Western Pacific -- could prove more difficult, he said.
The rubella vaccine, 95 percent effective at preventing infection, was first licensed in 1969.
Pan American Health Organization member countries in 1994 set goals of eliminating measles from the Americas by 2000, and rubella and congenital rubella syndrome by 2010. The measles goal was achieved two years behind the target date, in 2002. Rubella and congenital rubella syndrome were wiped out on schedule, although the official announcement was not made until this year to ensure that the disease had indeed been eradicated.
The U.S. has backslid on its measles eradication in recent months. A measles outbreak originating this year from California's Disneyland infected 117 people. The outbreak triggered a national debate about mandatory childhood vaccines.