Hantavirus Outbreak on MV Hondius Kills Three, Prompts Fears of Spread

Fear of hantavirus currently outpaces the threat from the virus itself on the MV Hondius cruise ship. Eight passengers became infected after the ship departed Argentina, where the Andes strain circulates, and three died from hantavirus pulmonary syndrome.

The outbreak recalls the Diamond Princess quarantine off Japan in late January 2020. That ship carried 3,711 people, 712 of whom contracted COVID-19 from SARS-CoV-2, another single-stranded RNA virus. But similarities end there. The Andes strain causes deadly hantavirus pulmonary syndrome, and cruise ship conditions aid contagion spread.

Questions persist about how the virus reached the ship. A Dutch couple reportedly caught it before boarding during a bird-watching trip through Argentina, Chile and Uruguay, likely from rodent droppings, urine or saliva. The other eight cases suggest human-to-human transmission, uncommon for hantavirus. A flight attendant also appears to have acquired it from an elderly Dutch passenger who later died.

Experts consider viral changes unlikely. The Andes strain spreads human-to-human with difficulty. A Chilean study found 1 percent transmission among household contacts and 17 percent among sexual contacts. From November 2018 through February 2019, person-to-person spread of Andes virus in Chubut Province, Argentina, caused 34 confirmed infections and 11 deaths.

Hantavirus cases stay low worldwide. The U.S. sees 15 to 50 annually, mostly Sin Nombre strain with no human transmission. The Americas report 150 to 300 cases yearly. Europe and Asia log 10,000 to 100,000, all from non-transmissible strains.

Three facts clarify hantavirus risks. First, human spread occurs only with close contact, mainly sexual, and just with Andes strain. Second, pandemic potential is low since it mainly affects rodents and case numbers hold steady. Third, U.S. cases rarely cause fatal pulmonary syndrome, which kills about 40 percent of victims; most bring diarrhea, muscle aches and fever. Actor Gene Hackman's wife died of HPS after rodent exposure.

Authorities in South Africa and Europe should trace contacts from disembarked passengers. Public health officials plan to quarantine the ship's 150 passengers and crew upon Canary Islands arrival, using cabin isolation, disinfection and an eight-week incubation watch. Virologists need to study the genetic structure of this Andes strain.