Q: I thought measles was eradicated, so how is there a new outbreak now?
A: Measles is caused by the rubeola virus. It is extremely contagious; up to 90% of those exposed to the virus (even entering a room where a person with measles was two hours earlier) will contract the disease, with symptoms typically starting one to two weeks after exposure. They then have a prodromal illness with fever (as high as 103 or higher), malaise, loss of appetite, conjunctivitis, cold-like symptoms, a cough and/or Kolpik spots (a ‘grains of salt on a red background’ rash inside their mouths by the rear molars).
After a few days to a week of these prodromal symptoms, the patient will develop the measles rash (a red rash that is slightly raised and can be palpated when you run your hand over it), which starts on the head and progresses down the body (like the rash was ‘poured over’ the patient’s head). These lesions eventually become confluent and mesh together, and after two or three days begin to fade, typically lasting three to five days total. The cough may persist for a couple of weeks.
Complications of measles include respiratory problems including pneumonia; neurological problems including encephalitis (an inflammation of the brain); weakened immune system, opening up the possibility of acquiring bacterial infections in addition to the measles infection; and many other complications ranging from ear infections to life threatening inflammations of other body organs.
Overall, almost a quarter of patients have some complication, although many are mild and resolve on their own. Over 1% of patients have severe enough disease that they need hospitalization, and the overall death rate from measles and its ensuing complications is about one in 1,000. There is another complication of measles that is important to mention, called subacute sclerosing panencephalitis (SSPE). This is a progressive and usually fatal inflammation of the brain thought to be due to an autoimmune reaction that occurs years (typically 5 to 10 years) after the measles infection.
The measles vaccine is a live attenuated vaccine, and although many people get a mild reaction to it (fever or a mild rash), only 1 in 10,000 suffer a severe reaction and many studies have shown there is no increase in autism. A series of two shots, the first shot is recommended at 12- to 15-months of age (mom’s antibodies have protection for baby before then) and the second between ages 4-6, offers 97% protection, and in the small number that still get measles the disease is milder.
The efficacy of the measles vaccine, first introduced in 1963, has radically changed this disease, essentially eradicating measles in the U.S. by the year 2000, and worldwide saving over 20 million lives since 2000. Unfortunately, because the disease is still endemic in some countries and too many people are foolishly not getting their recommended vaccinations, a traveler with measles can now set off a widespread outbreak in the U.S., and that is exactly what has occurred.
Jeff Hersh, Ph.D., M.D., can be reached at DrHersh@juno.com