Cornell University is warning that COVID-19 infections are on a scary rise, with a total of 47 active cases — all but eight of which were linked to student athletes — resulting from students’ “dangerous disregard” of anti-virus guidelines.

And the problem is likely to get worse at the prestigious Ivy League university in upstate Ithaca, provost Michael Kotlikoff said Thursday.

“We expect the size of the clusters to grow further over the coming days as we learn the results of pending tests,” Kotlikoff said in a statement.

The top-tier school said two clusters had grown to 39 positive cases by Thursday; eight other cases aren’t linked to them.

“While these clusters represent approximately only 0.1% of our campus population, and a very small percentage of our student-athletes, it points to a dangerous disregard by a group of students for the behavioral guidelines that we established to protect the public health of our community,” he said.

The alarming rise triggered a “yellow alert” on campus, and could mean more frequent testing, a possible reduction in on-campus space capacity and student gatherings limited to 10 people or fewer, with social distancing and masks required, the provost said.

All the infected people are in isolation.

“To be clear, however—all is not well,” Kotlikoff scolded. “Far from it. There is potential for just a few small student gatherings to destroy all our plans for an in-person semester.”

He said the case numbers still represented “a manageable situation,” but declared the “rapid growth ... puts us perilously close to needing to take drastic action, such as moving to wholly online classes for a period of time.”