Wade, the only wicketkeeper in the squad, is the second Australian cricketer after leg-spinner Zampa to have tested positive on Wednesday evening.
Wade was however scheduled to play in their rained out blockbuster clash against England on Friday.
“That’s highly possible (more COVID cases) really the way it’s gone. I suppose the strong point around that was that Matthew Wade was going to play tonight (Friday). So each individual is affected differently by the virus,” McDonald said after the match was abandoned without a ball being bowled.
Zampa had tested positive for COVID earlier and had to miss Australia’s win over Sri Lanka on Tuesday.
“Obviously, Zampa wasn’t quite right. We had a caution there to make sure he was ready to go for this game whereas Wade responded totally differently, less symptoms and he was ready to go tonight.
“(Zampa) Had to be isolated from the group. That was probably the only thing where we had to communicate separately from him, which is a little bit unique. But yeah, it’s a real possibility for all teams,” he added.
Ireland’s Geroge Dockrell is the other cricketer to have tested positive for the virus in the tournament so far, but took the field in the nine-wicket loss against Sri Lanka on Sunday.
The Australian government lifted the mandatory isolation requirements for COVID positive cases earlier this month.
As per the current ICC regulations, a positive test does not stop a player from playing in the ongoing T20 World Cup or training with his teammates.