The World Health Organization (WHO) is supporting response efforts following suspected cases of hantavirus infection on a cruise ship in the Atlantic Ocean, the UN agency said on Sunday.
One case of the rodent-borne disease has been confirmed to date and detailed investigations are ongoing, including further laboratory testing.
Of six persons affected, three have died and one is currently in intensive care in South Africa.
"Medical care and support are being provided to passengers and crew. Sequencing of the virus is also ongoing," WHO said in a statement posted on X.
In a separate tweet, WHO chief Tedros Adhanom Ghebreyesus said the agency "is facilitating medical evacuation of two symptomatic passengers, conducting a full risk assessment, and supporting affected people onboard."
He stressed that "rapid, coordinated action is critical to contain risks and protect public health."
Hantavirus infection is a rare disease linked to infected rodent droppings or urine that can cause life-threatening lung and heart problems.
The cruise liner-operated by a Dutch company-left Argentina three weeks ago and was ultimately heading for the Canary Islands but is currently sitting off the coast of Cabo Verde in West Africa, according to media reports.
WHO has also informed its National Focal Points according to the International Health Regulations, which outline countries' rights and obligations in managing public health risks, events and emergencies that could potentially cross borders. A public notice also will be issued.