A new report from the World Heath Organization (WHO) examining the transmission of Severe Acute Respiratory Syndrome (SARS concluded that at least one outbreak was the result of inadequate bathroom plumbing and drainage system maintenance combined with inappropriate ventilation systems.

There is evidence that, in human populations, SARS CoV is excreted in feces, vomit, respiratory secretions and urine. One outbreak cluster (the Amoy Gardens in Hong Kong), which affected 329 people and caused 42 deaths, was characterized by rapid spread of the infection between occupants of apartments in a multi-tower block complex. Modeling and simulation studies revealed that this spread was linked to fecal droplet transmission, which could be traced back to inadequately maintained water traps and reduced water use for bathroom cleaning, resulting in non-functional water locks of floor drains. This, combined with air movement instigated by overpowered bathroom extractor fans, created conditions that were highly conducive to virus transmission. The likelihood of re-entry of extracted air containing fecal droplets into other dwellings through upward air circulation in the narrow light wells between apartments added to the problem.