Brazilian health authorities have placed two people in isolation after suspected Ebola infections.
Officials later said tests on a Belgian man who arrived from Uganda showed no sign of the virus, but he will remain in isolation until all examinations are completed.
In São Paulo, doctors are treating a 37‑year‑old man from the Democratic Republic of Congo who has been running a fever.
Test results for both patients are expected next week.
If confirmed, these would be the first Ebola cases detected outside Africa since the current outbreak began in Congo.