Health officials in New Mexico are investigating the cause of death of an unvaccinated person who tested positive for measles, the state health department said Thursday.

The patient tested positive for the infection, but state health officials could not confirm that it was the cause of death.

Texas and New Mexico on Friday reported an additional 59 cases of measles for a total of 228 known infections in those states, where an outbreak that began in West Texas in late January has spread, causing the first U.