Medics were working on Monday to evacuate two people with symptoms of the deadly hantavirus after a suspected outbreak on a luxury cruise ship held off West Africa carrying mostly British, American and Spanish passengers, officials said.

Around 150 people were still stuck on the vessel after three people – a Dutch couple and a German national – died, and others fell ill, including a Briton who left the vessel and was being treated in South Africa, authorities added.

Hantavirus, which can cause fatal respiratory illness, can be spread when particles from rodent droppings or urine become airborne. It does not transfer easily between humans.

There are no specific drugs to treat the disease, so treatment focuses on supportive care, including putting patients on ventilators in severe cases.

The World Health Organization said the risk to the wider public was low and there was no need for panic or travel restrictions. But authorities in the island nation of Cape Verde said they had not allowed Dutch-flagged MV Hondius to dock as a precaution.

“We’re not just headlines: we’re people with families, with lives, with people waiting for us at home,” Jake Rosmarin, a U.S. travel blogger, said in a tearful Instagram video post from the ship on Monday.

“There is a lot of uncertainty and that is the hardest part,” he added.

The ship’s Netherlands-based operator, Oceanwide Expeditions, said it was looking into whether passengers could be screened and disembarked on the islands of Las Palmas and Tenerife.