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 New Mexico Health Department says there are now 30 cases of measles in New Mexico. This is a jump in 20 cases since the last update, which included one death. That person tested positive for the measles after their death.

New Mexico health officials say an unvaccinated adult has died after a measles infection, though the virus has not been confirmed as the cause. The death comes as cases rise in Texas and New Mexico, prompting the CDC to send a response team.