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.

There has been one confirmed measles death while officials in New Mexico determine if a recent death in the state was caused by measles.

In Texas specifically, a total of 223 people have contracted measles since the outbreak began in January, with at least 29 people, mostly children, requiring hospitalization. One child, who was unvaccinated, has died from measles, while a second unvaccinated person’s death is currently being investigated by health officials.