Jornal Do Brasilia - Hantavirus outbreak should formally end on July 2: WHO

However, while the episode is nearing the end for the remaining people in quarantine, for scientists and experts, the work is only in its early stages.

Virus samples will be worked on to see if tests, treatments and vaccines could be developed for future outbreaks.

There were 12 confirmed and one probable case stemming from the MV Hondius, including three deaths, in an outbreak which sparked an international health alert.

The Dutch-flagged ship set off April 1 from Ushuaia, Argentina, taking in remote islands in the South Atlantic Ocean, including Tristan da Cunha, before heading north to Tenerife in Spain's Canary Islands, where remaining passengers were evacuated.

WHO chief Tedros Adhanom Ghebreyesus said Wednesday that in total, more than 650 contacts were identified and followed up by health authorities in 33 countries and territories.

"All but 54 contacts have completed their period of quarantine, and the remaining contacts are scheduled to complete their quarantine period by July 2," he told a press conference at the WHO headquarters in Geneva.

"If no further cases are reported by then, WHO will consider the outbreak to be over."

- Studies and samples -

But he said the WHO would continue working to understand the outbreak, and the virus itself.

The UN health agency is working with partners who collected environmental samples on the ship, and coordinating a study among those exposed to the virus to better understand how the disease develops.

"We are also working on having a sample of the virus shared with the WHO BioHub in Switzerland," he said.

"This will be important for developing diagnostics, therapeutics and vaccines for future outbreaks."

Spread by rodents, hantavirus is a rare virus for which no vaccines or specific treatments exist.

The Andes species behind the Hondius outbreak is the only strain of hantavirus known to be able to jump from human to human.

The polar exploration ship finally docked on May 18 in Rotterdam harbour in the Netherlands.

The British island of Tristan da Cunha -- population 220 -- held a party on Saturday to celebrate the end of the virus threat to their tiny community, after the final group of people finished quarantine.

After an islander who disembarked from the Hondius fell ill, a British army specialist team parachuted onto the island -- one of the world's most isolated settlements -- to provide medical care and emergency supplies.

M. Andrade--JDB