Most hantaviruses are not known to spread between people. Andes virus is the exception. After the initial spillover from infected rodents, it is the only hantavirus with well-documented person-to-person transmission.

The hantavirus from the MV Hondius outbreak has been sequenced from samples taken from one of the infected individuals. The results confirm that it is the Andes strain, the most virulent and contagious,

A Virginia Tech disease ecologist said the outbreak of Andes hantavirus aboard the international MV Hondius cruise ship underscores how little scientists still know about the viruses circulating silently in wild rodent populations before they spill into humans.

The three individuals were not on board the hantavirus-stricken cruise ship, but came into contact with someone who tested positive.

Three King County residents are being monitored after possible exposure to Andes hantavirus linked to the MV Hondius cruise ship.

Hantaviruses are spread by rodents and can cause deadly respiratory and kidney illnesses in humans, although these infections are relatively uncommon globally.