Cape Verde8 hantavirus cases, 3 dead, aboard MV Hondius.
Andes hantavirus has a 30–40% fatality rate, no treatment, and can spread person-to-person, WHO says.
WHO is developing disembarkation procedures; the agency said 30 passengers from 12 countries face 42-day monitoring.
Sources: Ars Technica
THE PATHOGEN
Hantaviruses are rodent-borne RNA viruses in the Bunyavirales order. Most strains infect humans only through inhaled aerosols of dried rodent urine or droppings — a dead-end zoonosis. Andes orthohantavirus is the documented exception: it transmits person-to-person.
THE TWO SYNDROMES
Old World hantaviruses (Hantaan, Seoul, Puumala) cause hemorrhagic fever with renal syndrome — kidneys fail, mortality 1–15%. New World hantaviruses (Sin Nombre, Andes) cause hantavirus pulmonary syndrome — lungs flood with fluid, mortality 30–50%. Same family, different organ targets.
THE PRODROME TRAP
The first 3–7 days look like flu: fever, muscle ache, fatigue. Then within hours, capillaries in the lungs leak and patients drown in their own plasma. By the time HPS is recognizable as HPS, the cardiopulmonary phase is already underway and ICU admission is the only intervention that helps.
THE 1993 DISCOVERY
Hantavirus pulmonary syndrome was unknown to medicine until a cluster of healthy young Navajo adults died of acute respiratory failure in the Four Corners region of the US Southwest in 1993. CDC traced it to deer mice whose populations had exploded after an unusually wet El Niño year. The disease had probably been killing people for centuries; nobody had connected the cases.
WHY A SHIP IS THE WORST VENUE
Cruise ships combine three amplifiers: shared ventilation that recirculates aerosols, dense passenger contact, and a closed population that can't disperse during the 3–6 week incubation. The 2020 Diamond Princess COVID outbreak demonstrated the architecture; Andes' person-to-person transmission makes it a closer fit than any prior hantavirus event.
NO VACCINE, NO ANTIVIRAL
Ribavirin works against Old World hantaviruses if given early; trials against HPS strains have failed. There is no licensed vaccine for any hantavirus outside South Korea (where Hantavax targets Hantaan virus for military use). Treatment is supportive: ECMO, mechanical ventilation, and fluid management threading the needle between pulmonary edema and circulatory collapse.