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. This article originally appeared on Kitsap Sun: What is Hantavirus, and could we be at risk? However, the passenger who contracted Hantavirus while bird watching did not; his wife and another passenger died as well.

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. 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. For now, you should know that any Hantavirus infection originating in the United States requires direct exposure to contaminated rodents or their particles. The virus that infected passengers on a cruise ship in the Southern Hemisphere has made news.

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. Hantavirus is usually acquired through contact with the urine, droppings or saliva of infected rodents or contaminated surfaces. 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. There is no specific treatment for Hantavirus, it simply takes time to recover or die. Although, a few days later, the symptoms worsen, with shaking chills, coughing, and difficulty breathing.