Reacción a "Three people die in connection with a possible hantavirus outbreak on a cruise ship that departed from Argentina"

Hantavirus describes a family of viruses that are zoonotic, i.e. transmitted from animals to humans.  There are two major lineages of hantavirus: Old World Hantaviruses and New World Hantaviruses.  Old World Hantaviruses are found in Europe and Asia, New World Hantaviruses are found in the Americas.  In the current case we are most likely talking about Andes virus, which is a New World Hantavirus found in Argentina.

The danger with New World Hantaviruses is that they are both unspecific in early presentation which resembles flu-like diseases, and the progression to Hantavirus Pulmonary Syndrome which can be very severe with a case fatality rate of up to 40%.  Treatment is mainly supportive.  Given that the incubation period is one to eight weeks, more cases are still possible.

The most common route of Hantavirus spread is via rodents and their droppings (saliva, faeces or urine which can be aerosolised for example when cleaning, less commonly through bites and scratches), human-to-human transmission is possibly but very rare.  Given the timeline, there are multiple possible scenarios in this case: it is not entirely uncommon for rodents to hitch a ride on a ship which would be one possibility, people having been infected when the ship last made port in Argentina is another possibility especially given that incubation periods of up to eight weeks, and the last possibility would be human-to-human transmission which particularly at scale would be very unlikely.