Measles is a viral infection that usually starts in the respiratory tract. It is highly contagious, with the virus spreading to others by airborne droplets emitted when an infected person coughs or sneezes. These particles can remain in the air for up to two hours. People can also get infected by touching contaminated objects, surfaces, or hands. Those who are at risk of getting measles include unvaccinated children, pregnant women, and those with weakened immune systems.
Most people who get measles recover fully with no complications. However, the disease can cause severe illness and even death. Pregnant women, infants, young children, and those with weakened immune systems are at higher risk of severe complications. The vaccine can prevent measles in 95 percent of those receiving one dose and 99 percent receiving two doses.
People infected with measles should stay home until four days after the rash appears to avoid infecting others. They should not go to work or school or visit anyone else at home, including family members and friends. If they need to leave the house, they should wear a mask. If they have to visit healthcare facilities, such as emergency departments or GP surgeries, they should call ahead and let staff know they have measles so they can be isolated before they arrive. They should also use a mask when traveling on public transport.
Infected people may have a fever of 100 to 105 F (37.2 to 39.8 C). Other symptoms include a runny nose, stuffy or blocked ears, a cough, red eyes that itch and water, headache, and a rash that starts on the forehead and spreads down the neck, trunk, arms, legs, palms, and soles of feet. Sometimes, a rash that looks like blotchy spots may appear on the lips, inside cheeks, and throat. Some people with measles get a complication called subacute sclerosing panencephalitis, or SSPE, a brain inflammation that can cause deafness and other neurological problems.
Symptoms of measles typically start in early childhood, between the ages of 6 and 12 months. They then spread to the rest of the body.
A measles outbreak is considered a “notifiable disease,” the doctor who diagnoses a case must report it to public health authorities. The authorities then take steps to prevent or control the outbreak. The doctors can identify the people in contact with the sick patient and speak to them to determine whether they are immune to measles or have been vaccinated against it. If they have not been vaccinated, the doctors can help them get the vaccine. They should not give aspirin to children or teens if they have a fever, as this can lead to Reye syndrome. They should instead give them non-aspirin fever medicine such as acetaminophen or ibuprofen. Adults need to ensure they have received both doses of the measles vaccine before traveling overseas.