Coronavirus British couple contract pneumonia after leaving cruise ship
Mr Abel has been diagnosed with acute pneumonia, while Mrs Abel has a mild case.
The couple were on the cruise for their 50th wedding anniversary when it was placed in quarantine.
Steve posted video updates on the couple's YouTube channel alongside his wife Roberta last night and this morning.
He said "they are in a really bad way" and tweeted President Donald Trump yesterday in a bid to get his parents out of the Japanese hospital.
"UK government are not helping us.
"They say Japanese hospital is like a prison. Can you help? My folks are big trump supporters."
Other passengers who were trapped on the Diamond Princess cruise ship off the coast of Japan for more than two weeks have been brought back to the UK in a repatriation flight.
They will be isolated for a further 14 days at a facility on Merseyside.
In a statement issued after the flight landed, Foreign Secretary Dominic Raab said: "We have brought 32 British and European citizens safely home from Japan.
"The FCO worked hard to get them back to the UK securely.
"Our number one priority has consistently been the health and safety of UK nationals."
The four Britons on board the Diamond Princess who have recently tested positive for coronavirus were not on the flight, including David and Sally.
Since being kept on board the cruise liner in the port of Yokohama, a total of 634 passengers and crew have been infected, accounting for more than half of all the confirmed coronavirus cases outside of China.