Argentina Grapples with Rising Hantavirus Cases, Exceeding Outbreak Threshold

Escalating Hantavirus Infections Reported Across Argentina

Health authorities in Argentina have issued an alert following a notable increase in hantavirus infections. Since the beginning of 2026, 19 confirmed cases have been reported, contributing to a total of 79 cases since the start of the current epidemiological season in July 2025. This surge places the country above its established outbreak alert threshold.

The current epidemiological season, spanning from July 2025 to February 2026, has seen heightened activity, with approximately 70 confirmed cases and 20 deaths reported as of early February 2026. This translates to a concerning case fatality rate (CFR) of around 34.5%, which is the highest rate observed in the past seven years and exceeds historical national averages that typically ranged from 10% to 32% between 2019 and 2024.

Affected Regions and Viral Characteristics

The increase in cases has predominantly impacted the country's Central and Southern regions. Provinces such as Buenos Aires, Entre Ríos, and Santa Fe in the Central region, along with Neuquén, Río Negro, and Chubut in the South, have been particularly affected. The Buenos Aires Province alone reported 33 cases by mid-January 2026, double the number from the same period in the previous season. The Northwest region, including Salta and Jujuy, has also reported cases.

Hantavirus is endemic in Argentina, with various genotypes circulating. The Andes virus, a strain found in Argentina, is notable for its potential for human-to-human transmission, unlike other hantaviruses. However, no confirmed human-to-human transmission has been reported during the current season.

Symptoms, Transmission, and Prevention

Hantavirus infection, specifically Hantavirus Pulmonary Syndrome (HPS) in the Americas, typically begins with flu-like symptoms. These include fever (often above 38.5°C), muscle pain, headache, chills, and gastrointestinal issues such as nausea, vomiting, diarrhea, and abdominal pain. The illness can rapidly progress to severe respiratory distress, including coughing and shortness of breath.

Transmission to humans primarily occurs through the inhalation of aerosols contaminated with viral particles from the feces, urine, or saliva of infected wild rodents. Direct contact with rodents or their nesting areas also poses a risk.

Health authorities emphasize several preventive measures:

• Avoiding contact with rodents and areas showing signs of rodent infestation.
• Ensuring proper ventilation in enclosed spaces before entering.
• Using protective gear when cleaning rodent-infested areas.
• Securely storing food items to prevent attracting rodents.
• Cleaning and disinfecting homes with bleach.

There is currently no vaccine for New World hantaviruses, including those prevalent in Argentina. Early diagnosis and timely medical care are crucial for improving patient outcomes.