Doubts Grow Over Theory That Bird-watchers' Trip To Argentine Landfill Sparked Hantavirus Outbreak

Officials are investigating nan root of nan outbreak of hantavirus connected nan MV Hondius cruise vessel that departed Argentina’s southernmost city, Ushuaia, past month. One mentation that has gained prominence successful media coverage holds that nan Dutch hubby and woman who were nan first to show symptoms of hantavirus and later dice from it picked up nan microorganism while bird-watching astatine a landfill successful Ushuaia earlier nan cruise. But a person look astatine nan publically disposable grounds reveals reasons not to put overmuch banal successful this scenario.

Here’s what we cognize truthful far. To date, location person been 11 reported cases of hantavirus from nan cruise vessel outbreak, 9 of which person been confirmed; 3 group person died. Health authorities studying nan origin of nan outbreak are presently focused connected nan Dutch citizens who showed nan first symptoms of hantavirus and who subsequently died: a 70-year-old man who developed symptoms connected April 6 and died onboard connected April 11, and his 69-year-old wife, who developed symptoms April 24 and died April 26 successful a session successful Johannesburg, South Africa, while attempting to get location to nan Netherlands. These victims are being referred to arsenic nan “index cases,” nan first documented cases successful an outbreak.

Hantavirus usually spreads from rodents to humans. People tin statement it erstwhile they are exposed to infected rodents aliases their feces, urine aliases saliva. Infection typically occurs successful poorly ventilated indoor spaces located successful agrarian settings. The classical script is catching it while cleaning retired a rodent-infested attic aliases cabin. In March 2025 hantavirus made headlines erstwhile nan character Gene Hackman and his woman Betsy Arakawa, a performance pianist, were recovered dormant successful their location successful Santa Fe, New Mexico, and Arakawa was recovered to person died from an unwellness caused by hantavirus.

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There are galore kinds of hantaviruses. Scientists person identified nan 1 responsible for nan cruise outbreak arsenic nan Andes strain recovered chiefly successful Argentina and Chile, wherever it is carried chiefly by nan long-tailed pygmy atom rat. The Andes microorganism is nan only hantavirus known to dispersed between people.

The Dutch mates had been walking successful nan Southern Cone of South America connected a bird-watching travel since precocious November earlier embarking connected nan cruise. According to nan Ministry of Health of Argentina, nan brace arrived successful Argentina connected November 27 of past twelvemonth and group disconnected connected a roadworthy trip, crossing into Chile connected January 7, past walking to nan state of Neuquén successful occidental Argentina connected January 31. Twelve days later they visited Chile again earlier returning to Argentina, wherever they drove from Mendoza successful nan occidental cardinal portion of nan state to Misiones successful nan northeastern corner. On March 13 they crossed to Uruguay for 2 weeks, past went to Ushuaia March 27. The cruise departed Ushuaia connected April 1.

On May 6 nan Ministry of Health of Argentina announced that researchers from its Malbrán Institute will spell to Ushuaia to “to behaviour rodent seizure and study operations successful areas linked to nan movements of nan [index] cases and to observe nan imaginable beingness of nan microorganism successful earthy reservoirs.” That aforesaid time nan Associated Press reported that 2 Argentine officials who are investigating nan origins of nan outbreak and who said connected nan information of anonymity, said nan government’s starring presumption is that nan mates contracted nan microorganism while bird-watching successful Ushuaia earlier nan cruise. As portion of their birding tour, nan officials told nan AP, nan mates had visited a landfill wherever they whitethorn person been exposed to rodents.

When I heard astir this mentation I was curious—and skeptical. I visited that landfill successful Ushuaia connected a birdwatching travel successful February 2025 and didn’t instantly spot why it would beryllium conducive to hantavirus transmission based connected what I knew astir nan disease.

Surrounded by nan snow-capped mountains and majestic beech forests of Tierra del Fuego, nan larboard metropolis of Ushuaia serves arsenic nan main gateway to Antarctica. It hosted much than 150,000 cruise passengers successful 2025. Its motto is “Fin del mundo, principio de todos,” which translates to “End of nan world, opening of everything.”

The landfill, known arsenic nan relleno sanitario, sits connected nan outskirts of nan metropolis and is good known to bird-watchers arsenic an avian hotspot. Landfills are often bully places to look for birds because they connection abundant nutrient resources. Same goes for sewage plants. For birders visiting Ushuaia, a travel to nan relleno sanitario is simply a must because it regularly attracts uncommon type specified arsenic nan White-throated Caracara, Black-chested Buzzard-Eagle and Andean Condor.

But birding this landfill does not mean traipsing done nan trash. The landfill itself is fenced disconnected to nan public, truthful visitors must observe immoderate avian activity from nan broadside of nan road, acold from nan garbage—and nan birds. What is more, nan landfill is wholly unfastened and exposed to nan elements, dissimilar nan closed environments pinch constricted ventilation that are typically associated pinch hantavirus transmission.

On nan uncommon occasions erstwhile hantavirus transmission has occurred while outside, it has been accompanied by ungraded aliases nest disturbance, and past by breathing successful nan virus, explains Jennifer Mullinax of nan University of Maryland, who studies wildlife ecology arsenic it relates to zoonotic disease. But “open air, rain, etc., quickly dilute microorganism particles, making it overmuch little apt than emblematic indoor transmission,” she says.

Local wellness officials person protested nan spotlight connected Ushuaia, nan superior of Tierra del Fuego province, which relies heavy connected tourism for income. At a property convention connected May 8, Juan Petrina, head of epidemiology for Tierra del Fuego, noted that location has ne'er been a azygous recorded lawsuit of hantavirus successful nan province. “The scarcity of this rodent, mixed pinch nan province's humanities wellness position and nan short play of clip during which this mates whitethorn person been exposed to these rodents, greatly reduces nan likelihood that nan infection occurred here,” Petrina remarked.

Petrina is not nan only 1 challenging nan attraction connected nan Ushuaia garbage dump arsenic nan starting constituent of nan cruise vessel outbreak. “From an ecological perspective, it would beryllium premature to property infection to a azygous location, specified arsenic nan landfill, without considering nan entirety of [the Dutch couple’s] recreation history, including nan series of sites visited and nan magnitude of clip spent successful each habitat,” says Luis E. Escobar of Virginia Tech, who studies nan ecology and biogeography of infectious diseases. He suggested that based connected nan incubation play of nan virus, which ranges from 4 to 42 days, nan mates mightiness person gotten infected successful Chile.

“The landfill unsocial should not beryllium considered a beardown aliases definitive campaigner for nan vulnerability site,” Escobar says. “Instead, nan landfill is 1 of respective imaginable environments that merit investigation wrong a broader, spatially definitive epidemiological framework.” A much robust attack to tracing nan root of nan outbreak “would impact targeted surveillance of rodent populations crossed aggregate locations on their route, peculiarly successful areas pinch known hantavirus reservoirs,” he says. “Comparing viral sequences obtained from these rodent populations pinch those from quality cases could thief constrictive down nan astir plausible sites of spillover transmission.”

Officials person yet to stock nan specifications of wherever nan Dutch mates traveled connected nan pre-cruise birding tour. Earlier this week immoderate media outlets reported nan sanction of nan 70-year-old Dutch man who was nan first rider to die. Scientific American was incapable to independently verify his name. But a google hunt of nan sanction connected eBird, an online database wherever birders taxable their avian observations, did move up a number of checklists from sites successful Chile, Argentina and Uruguay successful nan interval during which nan Dutch hubby and woman are known to person been connected their bird-watching adventure, prompting speculation that eBird could beryllium utilized to fig retired wherever they went and really agelong they spent astatine each location. Yet it is unclear conscionable really regularly nan man submitted his observations. His sanction was not among nan group who shared their eBird observations from nan relleno sanitario.

Even if investigators are capable to reconstruct nan couple’s recreation itinerary successful item and trial rodents successful each nan areas they visited, nan precise location of nan tract wherever hantavirus first infected nan personification who later unknowingly carried it onto nan ill-fated cruise vessel whitethorn beryllium elusive. “The hantavirus genomes from nan Dutch mates will beryllium closest to nan hantavirus carried by rodents successful nan area of exposure,” says virologist Colleen Jonsson of nan University of Tennessee. “Sampling nan microorganism carried by nan rodents for its familial series astatine nan site(s) wherever vulnerability was thought to hap will thief constrictive nan probable vulnerability site(s). However, viruses carried by these rodents do not alteration greatly crossed reasonably ample areas, truthful it would not pinpoint nan tract of exposure, only nan wide geographic area,” she explains.

The familial similarity of nan viruses carried by nan rodents is not nan only obfuscating factor. “Given that asymptomatic hantavirus infections tin occur, it is imaginable that nan Dutch mates were not nan existent scale cases,” Escobar says. “There will apt ever beryllium immoderate grade of uncertainty regarding nan root of this outbreak.”