France, May 11 -- Health Minister Stephanie Rist confirmed that one of the five French passengers flown back from the MV Hondius cruise ship at the centre of the outbreak tested positive for the virus after exhibiting symptoms on Sunday.

Her condition "has unfortunately deteriorated overnight", she said on France Inter radio on Monday.

There are no vaccines or specific treatments for the Andes hantavirus, a rare disease that is usually spread among rodents. It is endemic in Argentina, where the ship departed from in April.

The World Health Organization recommends a 42-day quarantine and "active follow-up," including daily checks for symptoms such as fever.

The other four French passengers have tested negative, but will remain in hospi...