90-Second Read: What is Hantavirus, and could we be at risk? | Opinion

Shortly after sailing, a passenger became ill with Hantavirus, later determined to be the Andes strain. The first recognized outbreak of Hantavirus occurred in 1993 in the Four Corners region, where Arizona, Colorado, New Mexico, and Utah meet. Heavy rains of an El Nino weather pattern likely fostered the 1993 outbreak because it created ideal feeding and breeding conditions for the deer mouse, the most common rodent carrier of Hantavirus in the United States. The tiny, long-tailed pygmy rice rat, weighing just one ounce, is known to carry the Andes strain, the only Hantavirus which can spread from person to person.

Typically, fewer than 30 cases occur in the United States each year. To prevent Hantavirus, when cleaning out barns, sheds or attics, it is recommended to ventilate the space for 30 minutes, saturate the area with a 10% bleach solution, and wear personal protective equipment while cleaning. For now, you should know that any Hantavirus infection originating in the United States requires direct exposure to contaminated rodents or their particles. In early May 2026, the cruise ship MV Hondius embarked from Ushuaia, Argentina with plans to cross the Drake Passage and visit the Antarctic Peninsula.

Hantavirus is usually acquired through contact with the urine, droppings or saliva of infected rodents or contaminated surfaces. There is no specific treatment for Hantavirus, it simply takes time to recover or die. In 2025, El Nino brought above-average rainfall to central Argentina, following years of drought, which created conditions that favored rodent survival, reproduction, and the spread of Hantavirus infection. So, maybe the lesson from this most recent cluster of Hantavirus infections is that we should think twice about going birdwatching (or hiking in remote areas of Argentina and Chile) following a wetter-than-normal rainy season in South America.

At this time, the remaining passengers have been evacuated and repatriated to their home countries for quarantine and monitoring. Or maybe we should avoid those friends or family members who have spent time in those areas upon their return, since that strain spreads person-to-person. While no one is certain how the outbreak began, current evidence suggests that a man contracted the Andes virus by encountering a long-tailed pygmy rice rat while on a bird watching trip in Argentina.