90-Second Read: Hantavirus questions grow in the wake of a cruise ship outbreak

As public health officials around the world monitor dozens of former passengers and crewmembers of the MV Hondius for signs of Hantavirus infection, scientists are hoping to learn more about the mysterious and sometimes deadly virus that caused the outbreak. So far, evidence suggests the shipboard outbreak happened when one or two people were infected ashore and then passed the Hantavirus to others on board. Argentinian authorities dispute that the outbreak started at the landfill, pointing out that the rodents don't live in the Tierra del Fuego region of southern Argentina where the Dutch couple joined the cruise and that region has never had a human case of Hantavirus. Scientists still don't know why Andes Hantavirus is the only one shown to spread from person to person. But in Chile.

Close contacts may also be those who spend long periods of time together or health care workers who take care of Hantavirus-infected patients. Though, "there are so many cases of Puumala and Hantaan [Hantavirus infections] that I think if there were human-to-human spread, I think we would have seen it, and we would have caught it.… So there is clearly something different about Andes." R. Hantavirus pulmonary syndrome outbreak in Argentina: Molecular evidence for person-to-person transmission of Andes virus. Many different species and variants of Hantavirus have been discovered. Those are people who were on the Hondius when the first case died but disembarked before anyone realized Hantavirus was aboard.

That virus has been confirmed as the Andes species of Hantavirus, the only Hantavirus documented to spread from person to person. As of May 13, the outbreak had sickened at least 11 people, killing three. Scientists are still trying to decipher what makes the Andes virus different from other Hantaviruses. One reason that the Andes virus may spread among people is that it grows to higher levels in humans than other types of Hantaviruses do. If there's nothing special about Andes virus's genetic makeup, that might mean other Hantaviruses are capable of spreading among humans given the opportunity.

So, you know, maybe this is not about Andes, and every [Hantavirus] that is on a rat in a port in every part of the world actually is capable of doing the same," Palacios says. Still, many rodent species carry Hantaviruses that have unknown capabilities, Palacios says. Other experts doubt that human-to-human transmission has happened with Hantaviruses such as Puumala virus or Hantaan virus in Europe and Asia or Sin Nombre virus in the United States. With Andes, it's in the oral secretions." Klingström and colleagues also found that Andes virus can withstand antimicrobial compounds in human saliva that kill other Hantaviruses, even though it's susceptible to other methods to kill it. Like other Hantaviruses, "if we inactivate it with ethanol or anything else, it's super easy to kill," he.