All you need to know about: measles

Measles outbreak in the US, with 164 cases reported, highlights the importance of vaccination to prevent this contagious disease.

The United States is in the grip of a measles outbreak at present, with a major chunk of these cases in West Texas. As of February 27, 2025, a total of 164 measles cases were reported by nine jurisdictions: Alaska, California, Georgia, Kentucky, New Jersey, New Mexico, New York City, Rhode Island, and Texas, according to the Centers for Disease Control and Prevention, the country’s national public health agency. In 95% of these cases, the patients were unvaccinated or their vaccination status was unknown.

The outbreak, which began in late January, tragically claimed the life of a child, who was unvaccinated -- the first such death in over 10 years -- and another unvaccinated man has since died after contracting measles, though his cause of death is yet to be confirmed. The United States declared measles eliminated from the country in 2000.

Here is all you need to know about the disease:

Measles is a highly contagious viral infection. It can affect anyone, but is more common in children. According to the World Health Organization, measles is one of the world’s most contagious diseases, spread by contact with infected nasal or throat secretions (coughing or sneezing) or breathing the air that was breathed by someone with measles. The virus remains active and contagious in the air or on infected surfaces for up to two hours. One person infected by measles can infect nine out of 10 of their unvaccinated close contacts. 

While the disease is generally thought to be mild, that is not always the case: it can lead to serious complications (especially in young children) and even cause deaths.

Any person who is unvaccinated is susceptible. Children under five, pregnant women and persons with compromised immune systems are at higher risk of severe complications.

Symptoms of measles (also known as rubeola) generally begin about 10 to 14 days after exposure to the virus. The symptoms do not appear all at once: they may start with a cough, runny nose, sore throat, fever and red, watery eyes. Tiny white spots (known as Koplik’s spots) may develop inside the mouth or the back of the lips a few days later.