What is measles?
Measles is a common viral infection that causes a typical rash followed by fever, cough and runny nose. It is uncommon in the United States because of an effective routine vaccination program. Prior to routine measles shots, millions of Americans were infected yearly. Measles continues to be a worldwide health issue and infects 20 million people annually. Every year, measles outbreaks are also reported in many regions of the developed world, which concern health authorities.
Why are there measles outbreaks in the United States?
Despite an aggressive vaccination program, there are still Americans who are vulnerable to measles infection. Infants under 1 year of age have not yet been vaccinated and are susceptible to infection. A minority of youngsters are not vaccinated because of religious beliefs or from fear of an adverse reaction to the vaccine. Finally, those who have received only one MMR vaccine may have lost immunity to measles and need a booster shot.
How is measles transmitted?
Measles, like many viral infections, is a highly contagious illness. If an individual is infected, then nearly all of his close contacts will become infected, unless they are immune. An important reason the disease spreads so easily is because people can transmit the virus before they know they are ill. Measles is spread through the air by coughing and sneezing or after contact from a contaminated surface. Measles virus can survive on doorknobs and tabletops for up to 2 hours.
What are the symptoms?
Measles symptoms are typical of many viral infections. They include a rash, fever, cough and runny nose. In most cases, the illness resolves in a week. About 20% of measles cases are not so fortunate. Complications may develop which include ear infections, pneumonia and encephalitis, a condition that can lead to deafness, seizures and permanent brain damage. In the developing world, measles has a fatality rate that can approach 25%.
How is measles diagnosed?
Physicians usually diagnose measles based on symptoms including the typical measles rash. Blood tests can confirm the diagnosis, but these cannot be performed until several weeks after recovery.
Is treatment available?
There is no effective medical treatment for measles. Like the common cold, the infection is cleared by the body’s own immune system. If measles complications develop, however, then a physician may advise certain medical treatments.
Can measles be prevented?
Absolutely! The measles vaccine is one of the triumphs of the medical profession. It is usually administered as the MMR vaccine, which protects against measles, mumps and rubella viruses. The vaccine contains live measles virus in a weakened form that can create immunity but not cause disease. In nearly all cases, vaccine immunity after 2 doses is lifelong.
Adults born before 1957 are assumed to have immunity and are not advised to be vaccinated. Certain populations are considered to be higher risk and vaccination should be strongly considered. These categories include college students, hospital workers, women of childbearing age and international travelers or cruise ship passengers.
Anyone who potentially has measles should limit contact with susceptible individuals and avoid crowded regions including air travel and public transportation.
Do international travelers need to be protected?
Definitely! The CDC warns that international travelers and cruise ship passengers face higher risks of measles infection and should have measles immunity before travel. Travelers should discuss the measles vaccine, as well as other important travel shots, with their travel doctors several weeks before departure.
Measles is also a public health issue related to foreign travel. About half of measles infections brought into the United States are carried by Americans returning from abroad. Therefore, it is important that American travelers are immune, not only to protect themselves, but also to prevent them from spreading the disease to others after they return.