WHO confirms Andes strain of hantavirus in cruise ship passengers

Health authorities have identified the Andes strain of hantavirus, which can be transmitted from person to person in passengers who were on a cruise ship at the centre of a deadly outbreak of the rare infection, officials said Wednesday.

The South African Department of Health said in a report that the information came from tests performed on the passengers after they were removed from the MV Hondius and flown to South Africa.

One of the passengers, a British man, is in intensive care in a Johannesburg hospital. Tests were performed on the other passenger posthumously in South Africa.

The World Health Organization (WHO) confirmed the presence of the Andes strain had been detected as a result of work conducted in collaboration with health authorities in South Africa, Switzerland, Senegal and Argentina. The Andes virus is found in South America, primarily in Argentina and Chile.

The virus is spread by rodents and, more rarely, people. To date, the Andres strain is the only type of hantavirus in which human-to-human transmission has been confirmed, usually through close contact, such as by sharing a bed or sharing food, experts say.

Hantaviruses can cause cardiopulmonary issues among patients and the virus can have a case fatality rate of up to 50 per cent, WHO says. Patients who are hospitalized can require supplemental oxygen or medical ventilation.

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WHO said the hantavirus has been confirmed in three individuals who were on the ship, and is suspected in another five others.

That number ticked up after authorities in Switzerland said Wednesday a man who returned from South America and travelled on the ship has tested positive for the virus and is receiving treatment.

Swiss authorities didn’t specify when exactly the patient was on board the Hondius.

A statement from the Federal Office of Public Health said that the man “returned to Switzerland after travelling on the cruise ship on which there were a number of hantavirus cases.”

The ship set sail from Argentina in late March and two of the first cases on board, a Dutch woman who died in South Africa and her husband, had travelled in Argentina and elsewhere in South American before boarding the ship, WHO has said.

South Africa’s Health Ministry also said that contact tracing was underway, with 62 contacts identified including flight crew and health-care workers. The contacts will be monitored until an incubation period has passed and none have been diagnosed with the hantavirus so far.

Health officials have previously said the disinfection measures are being carried out on the Hondius, and that out of caution, passengers have been isolated in their respective cabins.

Docked at Canary island

About 150 people are currently on the ship, including four Canadian citizens. Global Affairs Canada previously told CBC News there are no reports of Canadians being directly affected by the outbreak. 

WHO Director General Tedros Adhanom Ghebreyesus said Wednesday that three patients with suspected hantavirus cases have been evacuated from the ship and are on their way to the Netherlands.

“At this stage, the overall public health risk remains low,” he wrote on his X account.

The Dutch Foreign Ministry said earlier it was co-ordinating the evacuation of three patients, one of them with Dutch nationality, to the Netherlands, where they will be provided with care.

There had been some confusion about the medical transfer, though the ship’s operator, Oceanwide Expeditions, had said it was scheduled for Wednesday morning.

Cape Verde was meant to be the ship’s final destination, but the nation off West Africa has ​not allowed the vessel to put passengers ashore because of the outbreak.

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Maria Van Kerkhove, director of epidemic and pandemic preparedness and prevention at the World Health Organization said human transmission is uncommon, with most cases originating through contact with infected rodents, their waste or saliva.

Late on Tuesday, the Spanish Health Ministry said it had been asked by WHO to take the MV Hondius and had given its agreement “in accordance with international law and humanitarian principles.”

The ship was to dock at the Canary island of Tenerife, Spanish state broadcaster TVE reported on Wednesday, citing ⁠sources ⁠from Spain’s Health Ministry.

The leader of the Canary Islands said he was opposed to the move and requested an urgent meeting with Prime Minister Pedro Sanchez, but the decision was ultimately the responsibility of the ​central government, which supersedes regional authorities.