A measles outbreak in Texas’ South Plains neared 100 cases Friday, according to the Texas Department of State Health Services, which warned more cases of the highly contagious virus are likely to pop up in outbreak areas.

At least 58 cases of measles have been reported in West Texas within the last three weeks — marking the largest outbreak in the state in close to 30 years. The dozens of reported cases have mostly affected children,

An outbreak of the wildly contagious — and potentially fatal — measles virus is spreading in Texas, with experts estimating hundreds could be infected.