Here’s what science tells us about the risks of hantavirus

Andes hantavirus has emerged as a growing health concern after infecting at least 11 people and killing three in recent outbreaks. The virus gained attention following a cruise ship incident, but scientists highlight a 2020 study in Argentina detailing the largest documented outbreak between 2018 and 2019. In that case, one infected person spread the virus to 33 others, with most transmissions linked to three symptomatic superspreaders at a crowded indoor birthday party and a wake. Researchers found these individuals had higher viral loads, severe illness, and liver damage, with at least one infection occurring from brief contact. Transmission studies confirm Andes hantavirus can spread through the air, though it remains unclear whether droplets or aerosols are the primary route. The virus’s infectiousness rate of 2.1 is lower than measles or some COVID-19 strains but higher than influenza. Early containment measures, like isolation and social distancing, significantly reduced spread, suggesting awareness limits transmission risks. U.S. health officials initially stated transmission typically requires prolonged contact, but experts argue current CDC guidelines may underestimate airborne risks. Dr. Josh Schiffer, an infectious-disease modeler at Fred Hutchinson Cancer Research Center, notes most cases occur after symptoms appear, allowing time for contact tracing. Unlike COVID-19, superspreader events appear to drive outbreaks, making containment more manageable. The CDC updated its guidance last week, emphasizing transmission through direct contact, close spaces, or exposure to bodily fluids. However, researchers point to the Argentine study as evidence that casual interactions can facilitate spread, particularly in unsanitary or crowded conditions. Public health responses must balance containment strategies with accurate risk communication to prevent misinformation and unnecessary fear.