A French woman was taken from the MV Hondius cruise ship and has now tested positive for hantavirus, according to French health officials. The woman is being treated in a hospital in Paris, and her health became worse overnight. She was one of five French people brought back to France after an outbreak of the virus on the ship.

Health officials in the United States also confirmed that one American passenger from the ship tested positive, but does not have symptoms. International health agencies are watching passengers from over 20 countries to prevent further spread of the virus.

The outbreak is linked to the Andes virus strain, which can sometimes spread from person to person after close contact. At least eight cases have been confirmed or suspected, and three people have died so far. The World Health Organization is investigating the outbreak and has sent testing kits around the world.