CAPE TOWN, South Africa (AP) — A suspected outbreak of the rare hantavirus infection on a cruise ship in the Atlantic Ocean killed three people, including an elderly married couple, and sickened at least three others, the World Health Organization and South Africa's Department of Health said Sunday.

In a statement to The Associated Press, WHO said an investigation was underway but that at least one case of hantavirus had been confirmed. One of the patients was in intensive care in a South African hospital, the U.N.'s health agency said, and it was working with authorities to evacuate two other passengers with symptoms from the ship.

Hantavirus, which is found throughout the world, is spread by contact with the urine or feces of infected rodents like rats and mice. The virus gained attention after the late actor Gene Hackman's wife, Betsy Arakawa, died from hantavirus infection in New Mexico last year.

Hackman died around a week later at their home from heart disease.

READ MORE: What is hantavirus, the infection that killed Betsy Arakawa in New Mexico?

Hantavirus can lead to serious respiratory illness, WHO said. The virus can cause a severe and sometimes deadly lung infection called hantavirus pulmonary syndrome, according to the U.S. Centers for Disease Control and Prevention.

While rare, WHO said hantavirus infections can be spread between people.

"WHO is aware of and supporting a public health event involving a cruise vessel sailing in the Atlantic Ocean," the organization said. "Detailed investigations are ongoing, including further laboratory testing, and epidemiological investigations. Medical care and support are being provided to passengers and crew. Sequencing of the virus is also ongoing."

The South African health department said the outbreak happened on the MV Hondius cruise ship, which had left Argentina around three weeks ago for a cruise that included visits to Antarctica, the Falkland Islands and other stops on the way to Spain's Canary Islands on the other side of the Atlantic.

The MarineTraffic global shipping website identified the vessel as a Dutch-flagged passenger cruise ship. It located it as docked in Praia, the capital of Cape Verde, a country off West Africa, on Sunday night.

The first victim was a 70-year-old man who died on the ship and whose body was removed in the British territory of Saint Helena in the South Atlantic, South Africa's Department of Health said in a statement. The man's wife collapsed at an airport in South Africa trying to take a flight to her home country of the Netherlands, the department said. She died at a nearby hospital.

The department identified the patient in intensive care in a hospital in Johannesburg as a British national. It said that person fell ill near Ascension Island, another remote island in the Atlantic, after the ship left Saint Helena and was transferred from there to South Africa.

Around 150 tourists were onboard the ship at the time of the outbreak, South Africa's health department said. Several online tour operators said the Hondius, which is described as a specialist polar cruise ship, usually travels with around 70 crew members.

WHO said it was working with national authorities and the ship's operators to conduct a "full public health risk assessment" and provide support for those still onboard the ship.

South Africa's National Institute for Communicable Diseases, meanwhile, was conducting contact tracing in the Johannesburg region to identify if other people were exposed to the infected passengers in South Africa.

There is no specific treatment or cure for hantavirus infections, but early medical attention can increase the chance of survival.