Lewis, 73, was hospitalized in the northern city of Darwin earlier this week after falling ill on Sunday.
"He'll be fine...he's just not well enough to perform," the spokeswoman said.
Lewis planned to fly home to the United States in the next few days, she said.
Lewis became ill over the weekend and was taken to a Darwin hospital, but promised to resume his tour after he overcame what was initially described as a slight viral infection.
However, the tour was cancelled Wednesday after doctors diagnosed meningitis, a potentially fatal illness.
"We're hoping that he'll be out of hospital in the next couple of days," his spokeswoman said.
"He's on the mend, but obviously you'd not want to push something like this, because he's a gentleman of the age of 73."
It's not certain whether Lewis will be well enough to host his annual Labor Day Weekend telethon for the Muscular Dystrophy Association, or to what extent. Meningitis is an infection or inflammation of the membranes covering the brain and spinal cord.