The member for Cardiff Central – and shadow secretary of state for digital, culture, media and sport – was said to have been “laying low” due to symptoms of the virus since the end of December.
On Saturday, her team tweeted: “Jo has asked us to let you know that she is being treated in hospital for Covid. Thanks for all your good wishes we will give an update when we can.”
Labour leader Sir Keir Starmer replied to the tweet, saying: “Get well soon Jo, a dear friend and colleague.”
First Minister Mark Drakeford said: “All of our thoughts and best wishes are with Jo for a speedy recovery.
“Thank you to Jo’s constituency team for continuing to support Cardiff Central constituents at this difficult time.”