On Monday, provincial health officials said a man who had recently travelled in western Africa was in critical condition in hospital in Saskatoon.
They said the patient had visited Liberia and was being examined for a suspected case of viral hemorrhagic fever.
However, a WHO official has now said on his Twitter account that hemorrhagic fevers have been ruled out.
Gregory Hartl, WHO's head of public relations, said Ebola, Marburg, Lassa and two other diseases have been ruled out.
He said testing continues but the patient may have malaria.
Lab results will be coming from a lab in Winnipeg later today, Hartl said.