90-Second Read: Hantavirus outbreak: American oncologist who became cruise ship's de facto head doctor speaks to ABC News

After the MV Hondius' doctor contracted the Hantavirus, one American doctor onboard jumped into action to help passengers. Stephen Kornfeld, an oncologist from Bend, Oregon, told ABC News that he quickly realized he was leading the response to a full-blown medical crisis on board the cruise ship. None of the 17 Americans onboard the boat have tested positive for the virus as of Saturday afternoon.

The ship's unidentified doctor was among the six people onboard who tested positive for the virus. A Dutch woman who tested positive died on April 26 in South Africa while a German woman who tested positive died on May 2. The boat is slated to arrive at the Canary Islands Sunday morning where the passengers will disembark and be flown back to their home countries.

Kornfeld, who went bird watching while on the cruise, told ABC News that the whole ship came together to get through the crisis. Centers for Disease Control said the Americans will be flown out to Nebraska where they will be evaluated, but there will be no mandatory quarantine. A British man who tested positive is hospitalized in South Africa while a Swiss man is hospitalized in Switzerland.