Experts have identified May 19 and June 21 as key dates to check whether the hantavirus outbreak on the cruise ship Hondius has spread beyond the vessel. Three people have died and several others fallen ill.
The outbreak began aboard m/v Hondius, which last docked in Tenerife. Leo Schilperoord, 70, from the Netherlands has been identified as patient zero. His wife Miriam Schilperoord, 69, later died from the virus.
Thirty passengers left the ship before the infection was known and have likely met hundreds of others in recent weeks. No cases have yet been confirmed outside the vessel.
American doctor Steven Quay says the incubation period means any spread to a third generation could appear around May 19. If no new cases emerge then, the next check date is June 21.