The number of measles cases associated with an outbreak in western Texas has grown to 259, according to new data released Friday.

Texas and New Mexico on Tuesday reported an increase of 28 cases of measles in the last five days, bringing the total known infections to 256 in the two states since an outbreak began in late January.

Nearly 230 measles cases have been identified in outbreaks in West Texas and a nearby New Mexico county. One hundred ninety-eight measles cases have been reported in the West Texas outbreak, the Texas Department of State Health Services said in an update Friday — 39 more confirmed cases since an update on Tuesday.