A Dutch crew member from the cruise ship hit by an outbreak of hantavirus has tested positive while isolating in the Netherlands.

The new case, announced by the World Health Organization (WHO) on Friday, brings the total number of infections linked to the outbreak on the MV Hondius up to 12. Three people have died.

“Today, the Netherlands confirmed an additional case among a crew member who disembarked in Tenerife, was repatriated to the Netherlands and has been isolating since then,” Dr Tedros Adhanom Ghebreyesus, the WHO Director General, told a press conference.

The MV Hondius reached its final destination, the Dutch port of Rotterdam, earlier this week.

Only crew members were still on board and they were tested for the virus on arrival.

They are now isolating in mobile homes kitted out with food and satellite communications.

One of the challenges in dealing with the outbreak has been the long incubation period of the virus – it can take up to 60 days for symptoms to show.

More than 6,000 contacts have been traced across 30 countries and the WHO have indicated that there are still a small number of high-risk contacts that need to be located.

“I thank the many countries that have cooperated in the response including Argentina, Cabo Verde, Chile, Netherlands, South Africa, Spain, the European Union and the United Kingdom,” said Dr Tedros.

Nationals from Switzerland, France, Spain, US, UK and now the Netherlands have all now tested positive since returning to their home countries.

The WHO has recommended a period of 42 days of isolation for those leaving the ship.

The virus is believed to have been brought onto the ship by a Dutch couple who had been travelling in South America on a bird-watching trip.

Hantavirus usually circulates in rodents but can infect people who come into contact with their urine, droppings or saliva.

The strain involved in the MV Hondius outbreak, known as the Andres strain, is unusual because there is some evidence that it is able to spread from person to person.

Some 20 Britons who were exposed to the disease on the ship have volunteered for a study that is meant to help to counter a lack of knowledge on the Andes strain, for which there are no approved vaccines.

Read More: Dutch cruise ship crew member tests positive for hantavirus in isolation