Measles is one of the most highly communicable infections. It’s spread through direct contact with infectious droplets or through the air (less common). For persons who are unimmunized and have never been exposed to the virus, the likelihood of contracting measles is 90% in close-contact settings. Patients with measles infection are contagious from four days before the rash through four days after the rash appears.
People typically develop symptoms such as fever, runny nose, red and watery eyes and a cough eight to 12 days after their initial exposure to the virus. The characteristic measles rash appears three to five days after the first symptoms.