In the last three weeks, 48 cases of measles have been identified, sending 13 patients to the hospital, according to the Texas Department of State Health Services.

Measles is marked by high fevers and a telltale rash. People can spread the infection from four days before the rash develops to four days afterward. In addition to the miserable illness, measles can cause complications, particularly in children younger than 5, pregnant people, adults over the age of 20, and people with compromised immune systems.

A growing measles outbreak in west Texas has infected 48 people, according to official state data released Friday -- the latest sign that the once-vanquished childhood disease is making a comeback as vaccination rates decline.