Some private schools have shut down because of a rapidly escalating measles outbreak in West Texas. Local health departments are overstretched, pausing other important work as they race to limit the spread of this highly contagious virus.

A fast-growing measles outbreak in West Texas has nearly doubled in just one week, now totaling 90 cases across seven counties and spreading to New Mexico. Earlier this week, the Texas Department of State Health Services confirmed 49 cases in five counties.

At least 58 cases have been confirmed. Health officials — who are scrambling to get a handle on the vaccine-preventable outbreak — suspect 200 to 300 people may be infected.