Measles can claim the dubious distinction of being the world's most contagious disease. One infected person in a crowded room can spread the disease to nearly every other person present who hasn't been vaccinated. Primarily a childhood viral illness spread through airborne droplets from nasal secretions, measles ranks among the top four childhood killers worldwide, especially among young, malnourished children with undeveloped or compromised immune systems. The tragedy is, measles can be prevented with a vaccine that costs a mere 26 cents per dose — a vaccine which has yet to reach many of the world's poorest countries.
Characterized by a widespread red rash, cough, sore and red-rimmed eyes, and fever, measles was first described by the 10th-century Persian physician al-Rhazes. He believed measles was a natural stage of childhood rather than an infectious illness. He called the disease hasba, meaning "eruption." Its current name derives from the 14th-century Arabic word miser, meaning the "unhappiness of lepers." (In fact, measles was sometimes known as "little leprosy.") The medical name for measles is rubeola, and it is sometimes called red measles to differentiate it from the much milder rubella, or German measles.
After spreading across North Africa to Europe during the 16th century measles was introduced to the Americas by European explorers. Christopher Columbus and his men carried both measles and smallpox to Native Americans, triggering widespread epidemics among populations with no previous exposure, and therefore no immunity, to the disease. In the United States in 1912, the first year for which there were nationwide statistics on the disease, 12,000 people died of the disease.
The measles virus was first isolated in a laboratory at Harvard University in 1954; an effective vaccine was licensed in 1963. At first, world health experts thought the disease could be eradicated by 1982, since measles affects only humans and there is no animal reservoir for the virus. When this deadline was missed, the eradication target date shifted to 1990. But instead of waning, measles cases began to rise. In developing nations, a child has a 5 percent to 15 percent chance of dying from measles. Of those children who do survive, many suffer serious complications, including blindness, loss of hearing, and nerve damage.
Since childhood vaccinations against measles became routine in many parts of the world, measles deaths have fallen by more than 80 percent compared to the pre-vaccine era. But the death toll remains stubbornly high across most of Africa and in some regions of South Asia, where vaccination has not yet reached all children. Today an estimated 750,000 people, mostly children, lose their lives to measles. Half of those deaths occur in sub-Saharan Africa; 200,000 occur in Asia; and the remainder take place primarily in the Middle East and northeast Africa. The World Health Organization reported in 2002 that fewer than half of all 1-year-olds in 15 African countries had been immunized.
One case of measles gives a person lifelong immunity; two doses of today's improved vaccine given during childhood does the same. (Boosters are recommended for those who may have received only one childhood dose or who may have received an older, less effective version of the vaccine. This is why many high schools and colleges in the United States now require older students to be re-immunized.) If 90-plus percent vaccination coverage worldwide can be reached, the population will achieve "herd immunity," a state in which immunization levels are so high that even the small minority not immune will still be protected.
There is no cure for measles; symptoms can be treated with fluids and painkillers like acetaminophen (e.g. Tylenol™). Infants, elderly people, and those with compromised immune systems may become severely ill with measles and die. Diarrhea, vomiting, and pneumonia are other possible complications.
In Latin America and the Caribbean, public health officials led by Dr. Ciro de Quadros and acting on the recommendation of the Pan American Health Organization pursued a strategy of "catch up, keep up, and follow up." This involved a single nationwide "catch-up" campaign to achieve 90 percent vaccination coverage; sustained routine maintenance to "keep up" to 80 percent coverage; and regular "follow-up" campaigns every three to four years. Through this effort, Latin American and Caribbean nations brought down the number of measles cases from 250,000 in 1990 to 537 in 2001. Now a number of countries in southern Africa are attempting to follow suit. The Measles Initiative, an alliance of many organizations including the Red Cross, the Centers for Disease Control, the World Health Organization, and UNICEF, began an effort to cut the death toll of measles by half between 2000 and 2005. In the first three years of the campaign, it's estimated that at least 270,000 deaths have been prevented.
What seems to work best is when routine immunization can be combined with special measles immunization campaigns. Sometimes vitamin A supplements, which can dramatically help reduce measles-caused deaths, are given at the same time as the immunizations. It's hoped that the Measles Initiative can repeat the success of the seven African countries which have reduced their numbers of measles cases from 60,000 to 117, and their number of reported measles deaths from 166 to zero.