(CNN) — Dozens of spring breakers from Texas boarded a plane for fun and came home with coronavirus.

About 70 people in their 20s chartered a plane from Austin, Texas, to Mexico for spring break two weeks ago. They went against the advice of White House officials who asked that people avoid gathering in groups of more than 10 and nonessential air travel.

Now 44 of those people have tested positive for coronavirus -- all of them University of Texas at Austin students, a university spokesman told CNN on Wednesday.

An elected official had a blunt message for the spring breakers.

"Quit being an a**," Texas House Speaker Dennis Bonnen told CNN affiliate KXAN . "Get over yourselves. Whether you think this is an issue or not, it is. Whether you think it could affect you or not, it does. The reality of it is, if I'm a college kid who's going to spring break in Mexico, you're affecting a lot of people. Grow up."

What's also alarming is that some of the passengers who went on the trip to Cabo San Lucas, Mexico, took commercial flights home, the Austin Public Health Department said.

Related content An open letter to my peers partying on the beach

Dozens of other passengers from the chartered flight are being monitored, public health officials said.

"The virus often hides in the healthy and is given to those who are at grave risk of being hospitalized or dying," Austin-Travis County Interim Health Authority Dr. Mark Escott said in a statement. "While younger people have less risk for complications, they are not immune from severe illness and death from COVID-19."

The local public health department and UT Health UT Health Austin and University Health Services have contacted all of the passengers on the plane using flight manifests from the Centers for Disease Control and Prevention.

The University of Texas at Austin is working to help public health officials.

Related content Is spring break canceled? Student getaways scuttled by coronavirus

"The university is working closely with Austin Public Health to assist in contact tracing," university spokesman J.B. Bird said. "The incident is a reminder of the vital importance of taking seriously the warnings of public health authorities on the risks of becoming infected with COVID-19 and spreading it to others."

The students who tested positive are in self-isolation, health officials said. The Department of State Health Services has been alerted.

University president Gregory L. Fenves urged students to practice good judgment and think about how their actions can affect others.

"(It) is our responsibility to follow local, state and national public health orders, and use good judgment during this crisis," Fenves said in a statement Wednesday. "Our conduct and the decisions we make have direct ramifications on our own health and the health of everyone in our city and beyond. We must do everything we can to limit the spread of this virus -- the consequences of reckless actions at this time could not be clearer."

Mayor Steve Adler issued a stay-at-home order for Austin on March 24.

Mexico was not under a federal travel advisory when this happened, health officials said.