The World Health Organization has said there are now nine cases of hantavirus, with two more being looked at, and the expectation is that more passengers from the MV Hondius will get sick.
WHO Head of Communications on Emergencies Nyka Alexander said that given the dynamics of spread on the cruise ship and the incubation period, the "amount of time from when you're exposed to when you might actually start falling sick can be up to six weeks with this virus".
Speaking on RTÉ's Morning Ireland, Ms Alexander said individual countries are implementing any quarantine of passengers once they return home.
Two planes with the last of the passengers from the MV Hondius travelled to the Netherlands.
The planes landed at Eindhoven Airport shortly after midnight, carrying eight Dutch nationals. Other passengers of different nationalities will continue on to their home countries from the Netherlands, authorities previously said.
Ms Alexander said that the recommendations from the WHO, in consultation with experts and with the countries involved as well, is there is a 42-day period in which people are quarantining either in a health facility or at home.
"That's the entire incubation period, so sort of starting the clock off at zero the moment they stepped off the ship as an excess of caution."
On any possible risk to the general public, Ms Alexander said: "Because those people are staying at home and not exposed to anyone else, the risk for the general public should be very, very low.
"Keep in mind that this isn't a new virus. It's one that we are familiar with. It's one in which there are cases every year. There are hundreds to thousands of cases of hantavirus every year.
"So, it's not new. And we've seen that when it's not in a ship where people are in such close contact with those very particular dynamics that you have in a closed environment, when it's back in a wider setting, a more open setting where people can stay away from others, it doesn't spread," she said.
Meanwhile, a Dutch hospital treating a hantavirus patient quarantined 12 staffers in a preventative measure.
The Dutch hospital staff members were placed into preventive quarantine for six weeks after blood and urine were handled without updated and more strict protocols, the Radboudumc hospital in the city of Nijmegen said, adding that the infection risk is very low and patient care continues uninterrupted.
Radboudumc admitted a Hondius passenger infected with hantavirus on 7 May.
"We will carefully investigate the course of events to learn from this so that it can be prevented in the future," said Bertine Lahuis, the chair of the hospital's executive board.
The MV Hondius set sail for the Netherlands late yesterday evening with 25 crew as well as a doctor and a nurse.
It is expected to arrive in the Netherlands by 17 May, ship owner Oceanwide Expeditions said.
Three people - a Dutch couple and a German national - have died since the start of the outbreak on the ship, which is usually spread by wild rodents but can also be transmitted person-to-person in rare cases of close contact.
The confirmed cases include a French passenger, who tested positive after the ship docked in the Canary Islands on Sunday. French Prime Minister Sebastien Lecornu yesterday said the passenger was in stable condition after her health had briefly worsened.
"Our compatriot who tested positive for Hantavirus is still in intensive care in a stable condition," he said. measures for prevention and control of transmission have been applied," it said in a statement.
One of 14 Spaniards quarantining at a military hospital in Madrid has tested positive for the virus, the Spanish Health Ministry said in a statement last evening, adding that the patient presented no symptoms and further tests were being done before a definitive result was announced.
At a press conference, WHO chief Tedros Adhanom Ghebreyesus, who is due to meet the Spanish prime minister in Madrid today, sought to reassure the cruise ship's passengers.
He said they were in good hands now and that the situation could have become difficult if they stayed on the ship but added that this "is not another Covid".
Search for contacts
Spain's health ministry defended the rigour of the evacuations, where medical teams escorted passengers from the ship to an airport on Tenerife under close supervision and following health checks.
"From the start, all the measures adopted have aimed at cutting the possible chains of transmission...all
In a video shared by Oceanwide Expeditions, captain Jan Dobrogowski paid tribute to the "unity and quiet strength" of everyone on board and highlighted the "courage and selfless resolve" of the crew.
The MV Hondius left Argentina, where hantavirus is endemic, on 1 April for a cruise across the Atlantic Ocean to Cape Verde.
The WHO believes the first infection occurred before the start of the voyage, followed by transmission between humans on board the vessel.
However, Argentine health officials have questioned whether the outbreak originated in Ushuaia, based on the virus's weeks-long incubation period and other factors.
