Climate change may be accelerating Argentina’s hantavirus surge, scientists warn

A deadly virus outbreak linked to an Antarctic cruise expedition has put health authorities in Argentina under mounting pressure as investigators race to determine where passengers aboard the MV Hondius were exposed to hantavirus before multiple deaths were reported.

The outbreak has sparked international concern not only because of the fatalities connected to the voyage, but also because Argentina is currently experiencing a sharp rise in hantavirus infections — with experts warning that climate change may be helping the rodent-borne virus spread into new areas.

Argentina sees spike in hantavirus infections

According to the World Health Organization, Argentina continues to record the highest incidence of hantavirus in Latin America.

The country’s Health Ministry confirmed 101 infections since June 2025 — nearly double the number reported during the same period last year.

The strain involved, the Andes virus, can cause hantavirus pulmonary syndrome, a severe respiratory disease that can rapidly become fatal.

Officials said the illness killed nearly one-third of infected patients last year, significantly above the average mortality rate of around 15 percent recorded over the previous five years.

Climate change concerns

Researchers say Argentina’s increasingly volatile weather patterns are creating ideal conditions for rodent populations that carry the virus.

Infectious disease specialist Hugo Pizzi said climate shifts are transforming the country’s disease landscape.

“Argentina has become more tropical because of climate change,” he said, warning that changing ecosystems are allowing disease-carrying rodents to thrive.

Experts say prolonged droughts often force rodents closer to human settlements in search of food and water, while heavy rainfall boosts vegetation and seed production, increasing food supplies and driving population growth.

Researcher Raul González Ittig said increased rainfall directly raises transmission risks by expanding infected rodent populations.

Virus spreading beyond traditional hotspots

Health officials say the epidemiological footprint of hantavirus has shifted dramatically.

While infections were historically concentrated in Patagonia, authorities say 83 percent of current cases are now being recorded in northern Argentina.

Fatal outbreaks have also been reported this year in Buenos Aires Province.

Pizzi warned that the Antarctic cruise outbreak may be an isolated event, but the broader public health threat is growing.

“This virus isn’t going anywhere,” he said.

Focus on Patagonia and Ushuaia

Investigators believe two Dutch passengers may have contracted the virus during a bird-watching excursion near Ushuaia.

Authorities are retracing the couple’s movements across Patagonia, where infections have previously been recorded.

Although Tierra del Fuego has never officially reported a hantavirus case, experts say symptoms can be difficult to identify in the early stages because they often resemble the flu.

Tourists may mistake the illness for a routine cold, delaying treatment.

Concerns have also intensified after Bariloche reported its first human hantavirus case of 2026 this week.

Cruise ship deaths raise alarm

Health officials confirmed that passengers aboard the MV Hondius tested positive for the Andes virus after three deaths were reported:

• A 70-year-old Dutch man on April 11
• His wife on April 26
• A German passenger on May 2

Because hantavirus can incubate for up to eight weeks, investigators are still trying to determine whether exposure occurred before passengers boarded in Ushuaia or during earlier travel through Argentina and Chile.

Authorities are now tracing contacts and monitoring possible exposures.

What is hantavirus?

Hantavirus is typically spread through contact with infected rodents or exposure to their urine, saliva or droppings.

People often become infected by inhaling contaminated particles, especially in enclosed or poorly ventilated spaces such as cabins, sheds and storage buildings.

While human-to-human transmission is considered rare, the WHO says it can occur with certain strains, including the Andes virus — making outbreaks particularly concerning when multiple close contacts are involved.