After unconfirmed theories began to spread that the hantavirus infection that struck a cruise ship originated at a landfill in Argentina's southernmost city, from where the ship set sail, local authorities were quick to deny it, The New York Times reports, according to UNN.
Details
"This is a maneuver to tarnish the image of Ushuaia as a tourist destination," said Martín Alfaro, a spokesperson for the local health ministry of the province that includes Ushuaia—the windswept gateway to Antarctic cruises.
"Malicious actors" in neighboring Chile, he added, describing it as a personal theory, could be spreading rumors to position themselves "as the only gateway to Antarctica."
As health authorities rushed to find the origin of the infection, which unnerved a world still suffering from the global coronavirus pandemic, the scientific investigation became intertwined with international mutual accusations.
The first two known victims of the hantavirus—a Dutch couple—had embarked on an extensive journey through Argentina, Chile, and Uruguay, complicating investigators' efforts to track the origin of the infection.
And while probabilities regarding the potential origin of the virus flourished, answers remained scarce.
According to health authorities, the Andes strain of hantavirus, which can be transmitted between humans and most likely caused the deaths of the first two patients traveling on the ship, is endemic in three provinces of Argentine Patagonia, where several cases are recorded annually.
But Argentina's Ministry of Health stated on Tuesday that the Dutch couple had not visited any of those areas during the days when they are believed to have become infected.
The Andes strain also exists in the Patagonian region of Chile, but the Chilean Ministry of Health stated that the Dutch couple visited the country before the virus's incubation period and ruled out that the infection could have originated there.
Federico Lada, a spokesperson for the Argentine Ministry of Health, refuted this claim, stating that infection in Chile remains possible. "That is not true," he said, referring to the statement from the Chilean Ministry of Health.
A Complex Search
The Argentine government stated that scientists analyzed the virus sequence from one cruise ship passenger and found it to be most closely related to cases identified in 2018 in the Argentine province of Neuquén. However, provincial authorities stated that the Dutch couple visited the region before the end of the incubation period, which lasts from one to six weeks.
Argentine investigators tried to reconstruct the extensive itinerary of the Dutch couple. They said the couple spent recent months traveling through Argentina, Chile, and Uruguay.
In the final leg of their journey before boarding the MV Hondius in Ushuaia, according to the ministry, they spent 20 days traveling by car from the wine-making city of Mendoza to the northeastern province of Misiones, and then spent two weeks in Uruguay. They returned to Argentina a few days before the cruise departed on April 1, the ministry reported.
Argentina regularly records hantavirus cases, but none of the areas the couple visited in recent weeks are considered at risk for the Andes hantavirus strain. Authorities said they are also trapping rats to study the virus.
According to Lada, the ongoing investigation is important for determining whether the Andes strain has spread to other provinces where it had not been previously reported.
"This would be a risk for the country," he said.
The Andes Strain
The long-tailed colilargo, a tiny rat that eats berries and rose hips, has been causing hantavirus cases in humans since at least 1996 in parts of the Argentine Patagonia region. But unlike what happened on the MV Hondius, where at least 11 people were infected, health authorities in Argentina are generally able to quickly isolate cases and prevent uncontrolled spread.
In Bariloche, a city and major tourist destination in the province of Río Negro, in Argentine Patagonia, a patient is currently in the hospital with hantavirus, said Dr. Rodrigo Bustamante, a physician who oversees epidemiology at the Ramón Carrillo Hospital in San Carlos de Bariloche. The patient, according to Dr. Bustamante, had no known connection to the ship.
Another patient is currently in the hospital with hantavirus in the neighboring province of Chubut, reported Sergio Wisky, the Minister of Health. The patient, he noted, "worked in the forests of Chile."
Dr. Wisky said he contracted hantavirus in 1996 while treating a patient during a deadly outbreak. In 2018, another outbreak in Chubut province, in the town of Epuyén, claimed the lives of at least 11 people.
Since then, according to Dr. Wisky, regular rodent monitoring and special outbreak protocols have been implemented in the province. In the three provinces where the Andes strain is endemic, health officials said they isolate people suspected of being infected with the virus, track their contacts, and disseminate information on the best precautions to avoid the disease.
According to officials, since 2018, only a few cases per year have been recorded in each of the three provinces. On board the ship, the virus was able to spread under conditions of close contact.
"This likely happened because the virus ended up on a foreign cruise liner where there were doctors who were probably unfamiliar with this disease and unaware of human-to-human transmission," Dr. Bustamante said. "Here, we have known about this for a long time."
The Landfill in Ushuaia
In Ushuaia, the port city in the southern province of Tierra del Fuego from where the cruise began, residents were unfamiliar with hantavirus, as not a single case had been recorded there since record-keeping began.
But the city suddenly found itself in the spotlight following media reports that authorities were investigating the possibility that a landfill might be the most likely source of infection.
The Argentine Ministry of Health stated that this is "not the most likely hypothesis."
Several passengers on board the MV Hondius were avid birdwatchers, and the Ushuaia landfill is an excellent spot for observing the white-throated caracara, a local bird of prey. However, several ornithologists in the area stated that such birds can be observed outside the landfill as well, and guides said they were unaware of any visit by the Dutch couple to that area.
Juan Pavlov, Secretary of Foreign Policy for the Tierra del Fuego Tourism Institute, stated it was unlikely the virus originated at the landfill, as truck drivers and sanitation workers at the site had never reported any symptoms.
"They would have gotten sick, infected, and possibly died," he said.
The Argentine Ministry of Health reported that investigators would travel to Ushuaia to trap and analyze rodents in areas related to the couple's route, aiming to identify the possible presence of the virus in an area they believe was not affected by it.
The Andes hantavirus strain is not typically found in Tierra del Fuego, but according to Lada, they still need to make sure.
Pavlov said he had to reassure tour operators who called them, concerned about potential hantavirus. Ushuaia, he said, "became a scapegoat."