Updated · University of Minnesota Twin Cities · May 15
Study Traces 15 COVID Cases to Shared Bathroom Vents in 7-Story Spanish Building
Updated
Updated · University of Minnesota Twin Cities · May 15
Study Traces 15 COVID Cases to Shared Bathroom Vents in 7-Story Spanish Building
3 articles · Updated · University of Minnesota Twin Cities · May 15
Fifteen COVID-19 infections in June 2020 were confined to four vertically stacked apartments in a seven-story building in Santander, even though citywide transmission had fallen to zero.
University of Colorado Boulder researchers linked the cases with viral sequencing, airflow tests and a CO2 experiment in a vacant unit that showed air was moving between apartments through a shared bathroom shaft.
The building’s late-1960s natural-convection duct system could reverse airflow when windows opened, kitchen fans ran or pressure shifted, sending infectious aerosols into bathrooms above and below.
Residents who had blocked or modified their bathroom vents were not infected, strengthening the study’s conclusion that the shared duct was the most plausible transmission route.
The findings echo Hong Kong’s 2003 Amoy Gardens SARS outbreak and underscore broader risks from shared air infrastructure in apartments, hotels, offices and cruise ships.
Could your neighbor's illness travel through your bathroom vent?
Can simply using your kitchen fan pull viruses into your home?
Shared Ventilation, Shared Risk: The Santander COVID-19 Outbreak and the Global Challenge of Airborne Disease in Old Buildings
Overview
In June 2020, a cluster of COVID-19 cases appeared in a residential building in Santander, Spain, during a time of very low community transmission. Investigations showed that the virus spread internally among residents of four vertically connected homes. Researchers found that the building’s old vertical bathroom ventilation duct system allowed infectious aerosols to move between stacked apartments, exposing residents to the virus. This highlighted how outdated ventilation systems can play a major role in airborne disease transmission, especially in older buildings, and underscored the need for better building standards to prevent similar outbreaks.