Carl Zimmer (@carlzimmer.com)

Hantavirus outbreak should reset WHO’s default approach to airborne risk The multinational outbreak of Andes hantavirus (ANDV) linked to cruise ship travel should prompt the World Health Organization (WHO) to change its default response to the risk of airborne transmission of the virus. Hantavirus is a pathogen with documented person-to-person transmission and high case fatality. Therefore, the starting point should not be to downplay the risk of airborne transmission until it is definitively proven. The starting point should be the immediate adoption of precautionary measures to reduce airborne transmission, such as respirator use by healthcare workers, cases, and close contacts; ventilation optimisation; avoidance of unfiltered air recirculation; and portable HEPA (high efficiency particulate air) filtration in all enclosed quarantine and transport settings. On 8 May 2026, WHO issued several documents that point in different directions. A Disease Outbreak News report acknowledged possible person-to-person transmission, but largely framed precautions around droplet and contact transmission outside aerosol generating procedures.1 By contrast, WHO’s guidance for managing contacts of Andes virus cases and disembarkation from the cruise ship adopted much more precautionary measures, including quarantine, universal respirator use during disembarkation, respirators for healthcare workers … https://www.bmj.com/content/393/bmj.s919