Prevention

Hantavirus prevention works along three axes that reinforce each other:

1. Rodent exclusion.Seal entry points larger than 6 mm (¼ inch) in walls, foundations, vents, and around pipes. Store food, pet food, and birdseed in rodent-proof metal or thick-plastic containers. Manage outdoor woodpiles (move 30 m from the house and 30 cm off the ground), keep grass short, and clear brush near foundations. Set snap traps for active infestation rather than glue or live traps, both of which prolong rodent stress and viral shedding.
2. Ventilate before entering closed buildings. For any enclosed space that may have housed rodents — cabins, sheds, barns, agricultural buildings reopened after winter — open all doors and windows and air it out for at least 30 minutes before doing any cleaning or sleeping inside.
3. Person-to-person precautions (Andes virus only). Never approach a person showing prodromal symptoms (fever, severe muscle aches, headache) of a known or suspected Andes virus case without barrier precautions, particularly in household or healthcare settings. Andes is the only hantavirus with documented human-to-human transmission, and the prodromal phase is when viraemia — and transmission risk — is highest.

The U.S. Centers for Disease Control and Prevention publishes a specific cleanup protocol for hantavirus risk areas (CDC: Cleaning Up After Rodents). The headline rule: never sweep or vacuum dry. Dry cleaning aerosolises rodent excreta — which is the primary infection route. Wet methods immobilise the virus before it can become airborne.

For known heavy contamination — large active nests, multiple dead rodents, structures with prolonged infestation — professional remediation by a service with hantavirus training is the appropriate response.

The Andes virus endemic zone covers southern Argentina, Chile, and adjacent areas of Bolivia, Paraguay, and Uruguay. Patagonia is the historically highest-risk region. The 2026 MV Hondius cluster originated from a cruise departing Ushuaia, Argentina (see the live outbreak map).

Practical traveller precautions:

• Avoid sleeping or storing food in unused rural buildings, agricultural sheds, or hunting cabins without verifying recent cleaning.
• If you must enter a long-closed cabin, open all windows and doors for at least 30 minutes before going inside.
• Never handle live or dead rodents directly. If you find a carcass, follow the CDC wet-cleanup protocol above.
• Camping: store food in sealed rodent-proof containers; sleep on a raised platform or off the ground when possible; avoid pitching tents over rodent burrows or near visible runs.
• If symptoms develop within five weeks of travel — fever, severe muscle aches, headache, breathlessness — disclose your travel history immediately to any clinician you see. The long incubation period of Andes virus (up to 39 days) means presenting clinicians may not connect symptoms to a remote trip without the prompt.

Andes virus is the only hantavirus with verified person-to-person transmission, so household precautions matter here in a way they don't for Sin Nombre or Old World hantaviruses. Per WHO and PAHO recommendations for Andes virus contacts:

• Limit close contact with the index case during the prodromal phase (the first 3–6 days of flu-like symptoms before cardiopulmonary collapse). This is the highest-viraemia window.
• Use a surgical mask or, preferably, an N95 respirator in shared rooms. Encourage the patient to wear a mask as well.
• Avoid sharing utensils, glasses, cigarettes, food, or any fomite that contacts the patient's respiratory tract.
• Wash hands thoroughly with soap and water after any contact with the patient or their immediate environment.
• Monitor all household contacts for symptoms for 42 days after their last exposure. The 42-day window covers the maximum documented incubation of Andes virus (up to 39 days) plus a margin.
• If any contact develops fever and severe muscle aches within the monitoring window, seek medical care immediately and disclose the household exposure history.

Several occupations carry elevated hantavirus exposure risk and warrant trained protocols and personal protective equipment:

• Rural agricultural workers handling stored grain, hay, or machinery that has sat over winter
• Wildlife biologists and ecologists studying small mammals — particularly field researchers handling rodents in endemic zones
• Forestry workers operating in Patagonian Andean forest (Andes virus reservoir habitat)
• Pest control workers entering rodent-infested structures
• Demolition and renovation workers entering long-closed buildings, attics, basements, and crawl spaces
• Healthcare workers treating suspected Andes virus cases — the only category of hantavirus where occupational person-to-person transmission has been documented (see Hantavirus — Andes Strain)

Recommended occupational PPE in high-risk settings: N95 or half-face respirator, nitrile or rubber gloves, protective eyewear, and trained adherence to the CDC wet-cleanup protocol. Where person-to-person transmission is a concern (Andes virus cases), full droplet and contact precautions per local infection-control guidance.