What you need to know about measles

Measles, a viral respiratory illness, typically presents with a high fever, fatigue, cough, nasal congestion and conjunctivitis of the eyes, followed by a rash. The rash appears as flat, red spots that start on the head and neck and spread down the body to the trunk, arms and legs. Patients are considered contagious for four days before and four days after the rash appears.

People at highest risk of developing measles include infants and children under 5; unvaccinated people; pregnant women; and people with compromised immune systems, such as those with cancer and HIV. Additionally, some adults who received only one dose of the vaccine as children may still have be susceptible to the illness.

Complications of having measles include ear and throat infection, pneumonia, diarrhea, swelling of the brain and death.

Measles is very contagious. One infected person will spread measles to 90% of the unvaccinated people around them. Measles is transmitted by direct contact with viral particles from an infected person who breathes, coughs or sneezes. The virus can remain in a room for up to two hours after the infected person leaves the area.

You have immunity to measles if you have one of the following:

• Written documentation of one or more doses of a measles-containing vaccine administered after 1968, on or after the first birthday, for preschool-age children and for adults not at high risk

• Written documentation of two doses of measles-containing vaccine after 1968 for school-age children and for adults at high risk, including college students, health care personnel and international travelers

• Laboratory evidence of immunity by checking for antibodies in the blood

After vaccination, the body’s immune system makes protective virus-fighting antibodies against the harmless vaccine virus. The measles vaccine protects against wild-type — or, naturally occurring — measles. If a vaccinated person is exposed to someone with measles, their immune system remembers how to fight the wild-type virus because the vaccine trained it.

In 1989, measles outbreaks among vaccinated school-age children prompted the Advisory Committee on Immunization Practices, the American Academy of Pediatrics, and the American Academy of Family Physicians to recommend a second dose of the MMR (measles, mumps and rubella) vaccine for all children.