Severe Acute Respiratory Syndrome (SARS)
Investigations of the global outbreak of SARS have shown that the major mode of transmission of the SARS virus is through close personal contact, in particular exposure to droplets of respiratory secretions from an infected person.
However, in a cluster of SARS cases in an apartment block in Hong Kong, sewage is believed to have played a role through droplets containing coronavirus from the sewage system. The World Health Organization sees the need for research to better investigate the modes of transmission of the SARS virus also through sewage and faeces, and potentially food and water. Investigation related to faecal-oral transmission would be precautionary in nature since there is no evidence or epidemiological indication that the virus can be transmitted through this route.