Calabrian man in quarantine after sharing a flight with a woman who later died of hantavirus.Biological samples from a 25-year-old Italian sailor from Calabria has been sent to Rome's Spallanzani Hospital - the country's main centre for infectious diseases - after he developed symptoms potentially consistent with hantavirus infection.  The man is already in quarantine after travelling on the same KLM flight from Johannesburg on which a woman later confirmed to have died of hantavirus had also been a passenger.   The transfer of samples on Tuesday was ordered to allow for full clinical assessment and to determine whether the man has tested positive for the virus.   The Spallanzani denied earlier media reports that the man had been transferred to the hospital for tests, stressing that it would be carrying out analysis on his biological samples, not on him in person.   Italy's health ministry had placed four Italian passengers under observation after they shared the connecting KLM flight to Rome with the deceased woman, who had been aboard the Dutch expedition cruise ship MV Hondius, the vessel at the centre of the hantavirus outbreak.   The four individuals, located in Calabria, Campania, Tuscany and Veneto, were instructed to be monitored by regional health authorities for up to six weeks - the maximum known incubation period for the virus.   The Andes virus strain behind the MV Hondius outbreak is the only known hantavirus capable of spreading between humans, and only through prolonged, close contact with a symptomatic person.   Both the World Health Organisation and the European Centre for Disease Prevention and Control have assessed the risk to the general population as low globally and very low in Europe.   The Italian health ministry has stated it is preparing hantavirus guidance, while stressing that the risk associated with the virus remains low.