Measles, also called rubeola, is one of the most contagious infectious diseases. It is marked by symptoms that are similar to a common cold, as well as a characteristic red rash. Less than two decades ago, measles was almost wiped out in the United States, thanks to vaccines.
Overall, the global incidence of measles and the mortality caused by the disease decreased by 66 percent and 74 percent between 2000 and 2010, according to the World Health Organization (WHO). Recently, the virus has had a resurgence. Since infection is becoming more widespread, it is important to understand the disease and how to prevent it.
Measles is caused by a virus. According to the Centers for Disease Control and Prevention (CDC) the virus lives in the nose and throat mucus of an infected person. When a person infected with the measles coughs or sneezes, the virus is spread to others.
According to the CDC, measles is so contagious that 90 percent of the people who stand near someone with the virus will become infected. Those infected can be contagious for four days before and four days after they get the measles rash.
The reproduction rate of measles is estimated at 12 to 18. This means that the average person with measles infects 12 to 18 other people who are near them, according to the Michigan Center for Public Health Preparedness. “Near means within 50 feet or entering a room where the measles person had been in — even two hours after the infected person left the room," said Dr. Aileen M. Marty, professor of infectious diseases at the Herbert Wertheim College of Medicine and member of the WHO Advisory Group on Mass Gatherings.
Rubeola should not be confused with German measles, also called rubella or three-day measles. According to the Mayo Clinic, rubeola and rubella share some symptoms, such as a red rash, but they are caused by different viruses, and rubella is not as infectious or as severe as measles.
Symptoms & diagnosis
According to Marty, most cases of the measles have some combination of cough, runny nose, red eyes, high fever and tiny white to blueish spots in the mouth. The infection progresses to develop the characteristic red rash. The measles rash is very easily identifiable. It typically looks like large, red, flat splotches on the skin. The patient may also have a dry cough. Almost all cases require treatment by a doctor.
To test for measles, a doctor will simply examine the patient for telltale symptoms, such as spots inside of the mouth and the skin rash. If a doctor has any doubt, a blood test may be ordered to confirm infection, according to the Mayo Clinic.
"This is a disease where complications are common — complications such as ear infection (acute otitis media), diarrhea and dehydration, pneumonia, encephalitis, and even death," Marty told Live Science. "In the United States, one to three of every 1,000 infected persons will die from its complications — which is better than in the Third World where as many as two to 15 per 100 infected persons die from measles and its complications."
Young children are much more susceptible to the virus. According to the Mayo Clinic, measles kills 100,000 people a year, most under the age of 5. Pregnant women and those with a compromised immune system are also at risk of severe complications.
There is no specific anti-viral drug that is used to treat measles. Instead, doctors treat the symptoms. "This means we provide/advise hydration, antipyretics (e.g. acetaminophen) for comfort and fever control, airway humidification in patients with respiratory tract involvement)," Marty said. Though not licensed in the United States for the treatment of measles, some pediatricians have used Ribavirin to treat severe measles pneumonitis, Marty added.
According to the Mayo Clinic, low levels of vitamin A can decrease the severity of measles. A large dose of 200,000 international units (IU) for two days can lessen the severity of the disease. Giving vitamin A therapy to patients has also been shown to reduce the mortality rates of children under the age of 2, according to research published by the U.S. National Library of Medicine. Marty agrees that this is a helpful treatment for patients over six months of age.
For many people, recovering from the measles includes resting at home until the symptoms subside. It is important for patients to drink plenty of fluids to replace fluids lost during fevers. It may also be helpful to use a humidifier to relieve congestion and to block out bright lights that may bother sensitive eyes, according to the Mayo Clinic. Once the disease has run its course, the person will be immune from the virus.
The best way to prevent the measles is by inoculation. Those who receive the proper vaccinations usually do not contract the measles virus. In fact, 997 out of 1,000 that are inoculated for measles never get the disease, according to the San Francisco Department of Health.
According to the March of Dimes, children should be vaccinated for the first time when they are between 12 and 15 months old, then again at 4 to 6 years old. "Children who are fully immunized are highly protected from acquiring common childhood diseases. The main risk remains with children who are not immunized and acquire vaccine-preventable diseases," Dr. Scott Lillibridge, a professor at the Texas A&M Health Science Center School of Public Health and an infectious disease expert, told Live Science.
Some reasons a child may not be vaccinated include: they are allergic to components of the serum, they have a compromised immune system or they are too young to receive the vaccine.
Getting the proper vaccinations not only protects the individual receiving the vaccine, it also protects those who cannot be vaccinated in what is called herd immunity. Herd immunity is when a non-vaccinated person is protected from a disease because all of the people in their community have been inoculated. Basically, a person can't be infected if all of the people he comes in contact with don't have a virus.
"While the reality remains that fully immunized children are at little risk of acquiring disease, it's important to note that vaccinations protect not only the child that was immunized, but, indirectly, others in the community as well," Lillibridge said. "Vaccines are one of the most effective tools we have to protect public health and prevent deaths around the world."
Herd immunity only works when a person remains around treated individuals, though. "People who aren’t vaccinated have a very low risk of being exposed to the virus or bacterium in question while in that area," Dr. Ivan Oransky, vice president and global editorial director of MedPage Today, told Live Science. "But it’s important to remember those unvaccinated people only have indirect protection, so if they are exposed somehow, particularly if they travel to an area where the virus or bacterium is in circulation, they can develop an infection."
To protect those who have been exposed to the virus, but have not been vaccinated, a doctor may order a post-exposure vaccination. If given within 72 hours of exposure, the vaccination may prevent the measles. Even if it doesn't prevent the disease, the vaccinated patient will only have a mild case of the measles, according to the Mayo Clinic. Another way to protect at-risk individuals is to inject them with immune serum globulin within six days of exposure to the virus. Like a vaccination, this treatment can prevent the measles or make the onset less severe.
Correction: This article was updated on Feb. 4, 2015, to correct the number of people who die of measles in the United States.