A concerning rise in hantavirus infections is prompting health officials in Argentina to issue warnings as the country edges closer to an epidemic threshold. With 19 confirmed cases reported since the beginning of 2026, the total number of infections since the start of the epidemiological season in July 2025 has reached 79. This figure surpasses the alert level for an epidemic, raising concerns about public health. The situation mirrors a trend observed in 2025, when 86 cases were recorded, resulting in 28 fatalities – a mortality rate of 33.6%, according to specialized travel health website vax-before-travel.
Hantaviruses, first recognized in the Americas towards the finish of the 20th century, are now identified in nearly all countries across Central and South America. The current outbreak is particularly concentrated in the central and southern regions of Argentina, including provinces such as Buenos Aires, Salta, Entre Ríos, Río Negro, and Jujuy. The Pan American Health Organization (PAHO) has issued advisories to travelers planning visits to rural or open areas within these regions, emphasizing the ongoing risk of hantavirus pulmonary syndrome (HPS) throughout 2026.
Understanding Hantavirus and its Transmission
Hantaviruses are a family of RNA viruses transmitted by rodents, making them unique within the Bunyavirales order, as most viruses in this family are spread by arthropods. The virus was first isolated from the Hantan River in Korea by Dr. Ho Wang Lee and his team, leading to the identification of the Hantaan virus and the associated Hemorrhagic Fever with Renal Syndrome (HFRS). While typically not spread person-to-person, rare clusters of human-to-human transmission have been documented in southern Argentina, according to reports.
The primary mode of transmission involves exposure to rodent urine, droppings, or saliva. Individuals can become infected by inhaling airborne particles when cleaning areas contaminated by rodents, touching contaminated objects and then touching their nose or mouth, being bitten by an infected rodent, or consuming food contaminated with the virus. The Centers for Disease Control and Prevention (CDC) provides detailed guidance on preventing hantavirus infections, emphasizing rodent control and safe cleaning practices. Learn more about hantavirus prevention from the CDC.
Symptoms and Severity of Hantavirus Infections
The clinical presentation of hantavirus infections varies depending on the specific virus strain. HFRS, prevalent in Eurasia and parts of the Americas, primarily affects the kidneys, leading to kidney failure. HPS, more common in the Americas, targets the lungs, causing severe respiratory distress. According to Wikipedia, with kidney syndrome, the incubation period lasts 2-4 weeks in humans. As the disease progresses, it goes through five phases: febrile, hypotensive, oliguric, diuretic, and recovery.
Symptoms of HPS typically appear 1-8 weeks after exposure and include fever, muscle aches, and respiratory problems. As the condition worsens, patients may experience shortness of breath, coughing, and fluid accumulation in the lungs. HPS has a high mortality rate, ranging from 38% to 50% in the American Southwest, according to data from the CDC. In Argentina, historical mortality rates from HPS have varied between 18.6% and 40%, depending on the region and outbreak, highlighting the importance of preventative measures.
Regional Concerns and Recent Cases
The current situation in Argentina is particularly concerning given the recent increase in cases. Nationwide, the National Epidemiological Surveillance System reported five new cases in the week ending February 14, 2026, primarily in the province of Buenos Aires. At least five deaths have been confirmed in Argentina during 2026. Neighboring Chile has also reported its first hantavirus fatality of 2026 in early February, in the Biobío region, indicating a potential broader regional trend.
The Challenge of a Vaccine
Currently, there is no FDA-approved or widely available vaccine against hantavirus, particularly for the New World strains prevalent in North and South America, such as the Andes virus, the primary causative agent in Argentina. In Asia, inactivated vaccines, such as Hantavax in South Korea, exist for Old World hantaviruses causing Hemorrhagic Fever with Renal Syndrome, but these are not effective or licensed for HPS. Research into DNA-based and recombinant vaccines is ongoing, including Phase 2 trials for Hantaan and Puumala viruses, but none have yet been approved for use in Europe or the United States.
The lack of a readily available vaccine underscores the importance of preventative measures, including rodent control, safe cleaning practices, and public health education. Health authorities are urging residents in affected areas to take precautions to minimize their exposure to rodents and their droppings. The PAHO continues to monitor the situation closely and provide guidance to member states.
Preventative Measures to Reduce Risk
- Rodent Control: Seal up areas where rodents can enter and build nests.
- Safe Cleaning: When cleaning areas contaminated by rodents, wear gloves and a mask, and spray the area with disinfectant before sweeping or vacuuming.
- Avoid Contact: Do not touch sick or dead rodents.
- Food Storage: Store food in rodent-proof containers.
- Awareness: Be aware of the risks in rural or open areas and take appropriate precautions.
The ongoing hantavirus situation in Argentina and Chile serves as a stark reminder of the importance of public health surveillance and preparedness. As the epidemiological season progresses, continued monitoring and preventative efforts will be crucial to mitigating the risk of further infections and fatalities. The absence of a widely available vaccine emphasizes the need for a multi-faceted approach, combining rodent control, public health education, and ongoing research into effective preventative measures.
Health officials will continue to monitor the spread of the virus and provide updates as they become available. The next official update from the Argentinian Ministry of Health is scheduled for March 15, 2026. Readers are encouraged to share this information with those who may be traveling to or residing in affected areas and to consult with healthcare professionals if they experience symptoms consistent with hantavirus infection.