Kelly lives in Columbus Ohio which is far from her mother in Sydney. Her mother is calling due to the recent news.

Source: live.axs.com

Mother: Hello?
Kelly: Yes, Mom.
Mother: Did you get my message? I sent you a screenshot of a news caption.
Kelly: Yes, I have. It's true, Mom. It's Tina, my roommate before.
Mother: O, Dear. How is she now?
Kelly: She is totally fine. No more symptoms.
Mother: Phew, good to hear that.
Kelly: It was a long time ago, by the way.
Mother: Still, take care of your health there.

What symptom are they talking about?