Measles is a highly contagious, airborne disease able to infect up to 90% of people who are not immune and come into contact with someone who has the illness, according to the CDC. Symptoms can include a rash, high fever, cough and runny nose, and typically appear anywhere from seven to 14 days after exposure to the virus.

The measles outbreak in West Texas now counts almost 600 cases, according to Texas health data released Friday. The 597 cases is 36 more than were tallied Tuesday, according to information from Texas Health and Human Services.