Health officials across Europe and Africa are working to trace contacts after a rare strain of hantavirus, known to allow limited human-to-human transmission, was identified among passengers from a cruise ship outbreak that has resulted in three deaths.
The World Health Organization (WHO) said Tuesday that eight people aboard the MV Hondius connected to the outbreak have confirmed or suspected infections. Five of those cases have been confirmed through laboratory testing, including a Swiss passenger who is now hospitalized in Zurich after disembarking during a stop at St. Helena Island.
South Africa’s health ministry said testing identified the Andes strain of hantavirus, primarily found in parts of South America, including Argentina and Chile.
The Andes virus is the only known hantavirus strain capable of spreading between humans, though such transmission is considered rare and usually requires prolonged close contact.
“This is the only (hantavirus) strain that is known to cause human-to-human transmission, but such transmission is very rare and… only happens due to very close contact,” the South African health ministry said in a statement.
The WHO said the virus type was confirmed by South Africa’s National Institute for Communicable Diseases and Geneva University Hospitals in Switzerland, with support from laboratories in Senegal and Argentina.
The outbreak has drawn international attention as the ship carried passengers through several countries and remote territories after departing Argentina in late March.
The vessel traveled through Antarctica and the South Atlantic islands before becoming stranded off Cape Verde, where authorities prevented passengers from leaving the cruise ship.
The WHO said three passengers were evacuated to the Netherlands on Wednesday for medical treatment. Dutch authorities identified them as a Dutch citizen, a British citizen and a German citizen. Two of the three were reported in serious condition.
The outbreak has killed a Dutch man believed to be among the first infected, his wife after she traveled to South Africa, and a German passenger aboard the ship.
Hantaviruses are typically spread through exposure to infected rodent urine, droppings or saliva, according to the WHO and the U.S. Centers for Disease Control and Prevention (CDC). Initial symptoms often resemble influenza but can progress to severe respiratory illness.
“This is not the next COVID, but it is a serious infectious disease,” WHO epidemic expert Maria Van Kerkhove said during a media briefing.
South African authorities said they have traced dozens of people who may have had contact with infected passengers, including health workers and airline personnel. Some of those contacts are believed to have traveled internationally.
Passengers remaining aboard the ship were reported to be asymptomatic and isolating in their cabins as the vessel travels toward Spain’s Canary Islands, where Spanish authorities plan additional quarantine and monitoring measures.
The Associated Press and Reuters contributed to this report.