Malbrán y CDC finalizaron operativo de vigilancia de hantavirus en sur de Mendoza

A team of scientists from Argentina's national infectious disease institute and the U.S. Centers for Disease Control and Prevention wrapped up an intensive field operation in the southern Mendoza region this week, hunting for rodents that might be carrying hantavirus. The work was sparked by a troubling outbreak: a Dutch couple fell ill with the virus after spending time in Malargüe before boarding the cruise ship MV Hondius, and health officials needed to understand how the infection had taken hold.

Over the course of several days, researchers set more than 250 traps across the scrubland and protected areas surrounding Malargüe—places like the Llancanelo wetland reserve, Bardas Blancas, Las Loicas, and the Caverna de las Brujas cave reserve. They worked in full protective gear, following strict biosafety protocols as they captured wild rodents, drew blood samples, and collected tissue. The sites were chosen based on ecological patterns and the known habitats of rodent species that can harbor the virus, particularly the long-tailed pygmy rice rat and two species of Abrothrix mice.

The preliminary field screening turned up no confirmed infected animals. Researchers identified two rodent species at the sites: the Abrothrix olivacea, which has shown positive antibodies in some individuals in the past but is not considered a recognized hantavirus reservoir, and the long-tailed pygmy rice rat, the primary known carrier of the Andes virus across much of Patagonia. But finding the animals was only the first step. All the blood and tissue samples were packed up and sent to the National Reference Laboratory for Hantavirus at Argentina's Malbrán Institute, where the real detective work would begin.

Dr. Carla Bellomo, who heads the Molecular Biology Service at the institute, explained that the field studies had not yet produced evidence that any of the captured animals were infected. "We need to continue with specific laboratory analyses to determine whether the samples show hantavirus infection," she said. The lab would run serological tests to look for antibodies against the virus, and if any samples came back positive, they would move on to molecular studies using RNA extraction and RT-PCR techniques to detect the actual viral genetic material.

Mendoza has never reported a confirmed case of hantavirus pulmonary syndrome, and the province has no documented history of the virus circulating among its wildlife. That absence of endemic disease is reassuring, though it also means the appearance of infected tourists raised urgent questions about where the exposure had occurred and whether the virus might be present in local rodent populations.

Beyond the field work, the visiting scientists also conducted training sessions with staff at the Núcleo Laboratory of Hospital Lencinas in the city of Godoy Cruz. The goal was to transfer the technical know-how for diagnosing hantavirus to local personnel, strengthening Mendoza's capacity to spot cases quickly and maintain integrated disease surveillance. That kind of institutional strengthening matters: if the virus is circulating anywhere in the region, early detection could mean the difference between a contained outbreak and something far worse.

The investigation is far from over. Lab results will take time, and researchers will be watching closely to see whether any of the rodents they captured are actually infected. For now, the field operation is complete, but the work of understanding how hantavirus arrived in Malargüe and whether it has established itself in the local animal population is just beginning.