Brilliant winger Ioane was in isolation for periods in London last week after medical staff identified he had contracted the infectious viral disease.
The same problem previously struck uncapped Crusaders centre Jack Goodhue, who stayed home through most of the first week of the tour. He missed what would have been an international debut against the Barbarians.
Goodhue has improved but Ioane is being carefully monitored and is an uncertain starter for the French clash in Paris on Saturday, the opening Test of the tour.
