Tracing the Origin of the Hondius Hantavirus Outbreak: Epidemiological Investigation Expands to Mendoza
Public health investigators are expanding the search for the origin of a fatal hantavirus outbreak linked to the polar cruise ship MV Hondius, shifting focus toward the land-based travels of two Dutch ornithologists in Argentina. The investigation, led by the Administración Nacional de Laboratorios e Institutos de Salud (Anlis Malbrán), now includes potential exposure sites in the southern Mendoza province and Neuquén, following a timeline that suggests the couple may have encountered the Andes Sur virus during their overland journey before boarding the ship in late March.
The investigation follows a strict epidemiological window of eight weeks prior to the onset of symptoms in the “index case,” Leo Schilperoord, which aligns with the couple’s travel through rural areas of Argentina and Chile in their motorhome.
Tracing the Path of the Virus
The investigation centers on the movements of Leo Schilperoord and Mirjan Huisman, who toured Argentina and Chile between November and March. Anlis Malbrán, working with biologists from the U.S. Centers for Disease Control and Prevention (CDC), conducted field research in Malargüe, Mendoza, to trap local rodent populations. Researchers are specifically looking for the long-tailed pygmy rice rat (Oligoryzomys longicaudatus), the primary reservoir for the Andes Sur virus, along with two other related species: Abrothrix olivácea and Abrothrix hirta.
While the couple visited several sites in Mendoza, including the Humedal Llancanelo and Caverna de las Brujas, local health officials remain cautious. Andrea Falaschi, Director of Epidemiology for the Mendoza Ministry of Health, noted that it is “very difficult and unlikely” that the couple contracted the virus specifically in Malargüe, given the incubation period. The couple’s travel history includes multiple border crossings via the Pehuenche Pass and stays in wilderness areas of Neuquén, where they arrived from Chile in late January.
The shift in geographic focus highlights the complex nature of tracing hantavirus, which is typically endemic to specific Patagonian regions. By extending the search beyond known endemic zones, investigators are testing whether the virus’s environmental footprint has expanded, a process that mirrors the rigorous contact tracing protocols used during the 2010-2019 Epuyén outbreak.
What Happens Next in the Investigation
Authorities are likely to continue analyzing the captured rodent samples to determine if any specimens carry the Andes Sur virus. The Centro de Ecología Aplicada de Neuquén (CEAN) is currently coordinating with the national laboratory to monitor sites in Neuquén where the couple stayed early in their journey. Investigators may also attempt to further reconstruct the couple’s exact overnight stops, though the lack of GPS data or photographic records of their motorhome makes definitive site identification challenging.
The MV Hondius outbreak resulted in the deaths of both Dutch travelers after they boarded the vessel in Ushuaia. Following the ship’s arrival in Tenerife, Spain, passengers underwent a controlled quarantine process coordinated by the World Health Organization. Future findings from the Anlis Malbrán laboratory could clarify whether the transmission was isolated to specific wilderness interactions or if the geographic range of the virus is broader than previously documented.
Frequently Asked Questions
Who were the primary individuals affected by the outbreak?
The primary cases were Leo Schilperoord and Mirjan Huisman, a Dutch couple aged 69 and 70, who were traveling through Argentina for birdwatching.
Why is the investigation looking at Mendoza?
The investigation expanded to Mendoza because the couple’s travel itinerary indicated they stayed in rural, wild areas of the province within the incubation window of the virus.
What rodents are being tested?
Researchers are focusing on three species: the long-tailed pygmy rice rat (Oligoryzomys longicaudatus), the olivaceous field mouse (Abrothrix olivácea), and the long-haired mouse (Abrothrix hirta).
What measures are currently in place to monitor the potential spread of the Andes Sur virus in these newly identified areas?