A 20-year-old British tourist in Italy has been quarantined despite testing negative for the deadly hantavirus after health officials traced her to the same plane where an infected passenger was travelling. 

She was located in Milan on Monday evening and taken to Sacco Hospital in the Lombardy region where she will remain in quarantine, local media reports.

'This time too, following the report we received from the Ministry of Health, we acted promptly and contacted the tourist identified from the United Kingdom as a contact of a hantavirus case,' emphasized Guido Bertolaso, Regional Councilor for Welfare.

It comes after another British man was quarantined last week in the same hospital despite also testing negative for the virus.

The man, in his 60s, was stopped at the guesthouse where he was staying in the Pasteur area of Milan, along with a 50-year-old man who had joined him in Italy.

Officials in Milan said they had been alerted by the UK Ministry of Health and had traced the men to their B&B late last Tuesday, and he and his companion were taken to the Sacco hospital by police.

He will remain in quarantine until June 6, with hantavirus tests repeated weekly until he finishes the isolation period, the Regional Center for Infectious Diseases explained. 

The man was deemed a 'close contact' of Dutch woman Mirijam Schilperood, who died in South Africa and was onboard MV Hondius.

Schilperood, who had been on the April 25 Airlink flight from St Helena to Johannesburg, was sitting in 13C, a subsequent positive hantavirus case sat in 14B, while the British passenger was in 15F.

The man had then flown on to Italy, where he had spent 17 days touring Rome, Florence, Venice and the Cinque Terre near Genoa.

Schilperood's husband Leon also died on the ship, and the two are thought to have contracted the deadly rat-borne Andes virus strain while travelling in southern Argentina, where it is prevalent.

Guido Bertolaso, of the health department at Lombardy council in Milan, said: 'Both men were identified at their B&B after details were provided by British authorities.

'One is in his 60s and a resident of St Helena, while the other is younger, in his 50s.

'Neither is showing symptoms of the virus, and both have tested negative, but the older man will remain in quarantine in Italy until June 6 to ensure he doesn't develop the virus. The younger man will be allowed to return home.'

It comes as the ship hit by a deadly hantavirus outbreak arrived Monday at the Port of Rotterdam for disinfection, carrying the body of a German victim.

The MV Hondius has spent the past six days sailing from the Canary Islands, where the remaining passengers were escorted off the vessel by personnel in full-body protective gear and boarded flights to more than 20 countries to enter quarantine. 

The outbreak on the ship has reached 11 cases, nine of which have been confirmed.

Three passengers have died, including a Dutch couple who health officials believe were the first exposed to the virus while visiting South America.

The vessel has made the journey from Tenerife up the coast of Africa and Europe with 25 crew members and two medical personnel.

According to the ship operator Oceanwide Expeditions, no one on board is experiencing any symptoms.

Crew members who are unable to return home will be quarantined in the Netherlands, where some two dozen passengers and crew are already, after arriving in the country on a series of flights over the previous two weeks.

Eighteen Americans are currently under observation at specialised healthcare facilities in the United States designed to treat people with dangerous infectious diseases.

After everyone on board has disembarked, the ship will be decontaminated based on Dutch public health guidelines.

'Personal protective measures are being taken to ensure that the cleaners do not need to quarantine after the cleaning,' the health ministry said in a letter to the Dutch parliament last week.

Public health officials will inspect the vessel before it is allowed to sail again. The hantavirus outbreak aboard the MV Hondius is the first known case on a cruise ship.

France's Pasteur Institute said on Saturday it has fully sequenced the Andes virus detected in a French passenger from the ship and found that it matched viruses already known in South America, with no evidence so far of new characteristics that would make it more transmissible or more dangerous.

Dr Bonnie Henry, British Columbia's provincial health officer, announced on Saturday that one of the four Canadians isolating in the province after disembarking the MV Hondius ship earlier this month received a 'presumptive positive' test.

She said the unidentified individual is part of a couple in their 70s from the Yukon who have been isolating since they returned to the country on May 10, and developed 'mild symptoms' on Thursday including a fever and a headache.

A test on the individual late Friday evening then came back positive for the Andes strain of hantavirus, which was later confirmed with further testing by the National Microbiology Laboratory in Winnipeg, according to the CBC.

The other person also had 'minor symptoms' when they were assessed, but tested negative for the virus.

'The patient [who tested positive] is stable, the symptoms remain mild at this point and they are still in hospital in isolation, being monitored and receiving care as needed by the healthcare worker team in the hospital,' Dr Henry said.

At the same time, she said, a third cruise passenger who was in isolation in British Columbia, also in their 70s, has been transferred to a hospital for assessment and testing out of an abundance of caution.

Meanwhile, a fourth person from British Columbia in their 50s who lives abroad, continues to isolate at home.

And nine Britons from St Helena and Ascension Island - who may have been exposed to the disease but do not have symptoms - were scheduled to arrive in the UK on Sunday evening, the UK Health Security Agency (UKHSA) said.

They will self-isolate in the UK and will be taken to Arrowe Park Hospital on the Wirral, which previously housed MV Hondius passengers.