Scientists around the world are investigating the possibility that the virus causing Severe Acute Respiratory Syndrome is spread not only through close contact but also through body waste.
World Health Organization epidemiologists on Tuesday were investigating the possibility that the virus causing Severe Acute Respiratory Syndrome could be spread through contaminated water.
Scientists working in WHO laboratories recently discovered that a virus linked to SARS shows up in the excrement of infected persons.
This led investigators to analyze water and sewage systems in Amoy Gardens, a Hong Kong apartment building where more than 230 people caught SARS in a matter of days. The city has 685 cases in total, more than a third of the world's estimated 1,600 cases. Sixteen people in Hong Kong have died from SARS.
Until last week, most cases in Hong Kong could be traced to a single visitor from mainland China. The rapid spread of the disease from hospitals to the community has alarmed and puzzled investigators.
Joseph Bresee, from the U.S. Centers for Disease Control, says many of the infected families of Amoy Gardens lived on the same side of the building. He says this "vertical cluster" has led scientists to look for clues in the building's water supply.
"It's one of the theories, that exposure to contaminated water by fecal material with virus in it might lead to infection," he said. "It's quite unusual to have cases that cluster like that in a building."
Hong Kong sealed the building on Monday and has since removed remaining residents who are not sick to a makeshift isolation center.
So far, scientists have found that the virus causing SARS is likely transmitted by droplets of mucus or saliva. WHO says people seem to catch the disease when they come into "close and sustained" contact with a very sick patient.
The head of Hong Kong University's microbiology department says scientists are looking for other possible modes of transmission in the Amoy Garden outbreak. These include a search for infected droplets on the building's mailboxes, garbage bins, and elevators. He also says the virus may survive far longer than originally believed.
Aside from quarantining people who may have come into contact with SARS patients, Hong Kong has closed all schools and encouraged disinfecting public transportation and parks.
SARS patients suffer from flu-like symptoms and high fever at first but can quickly develop a severe form of pneumonia. The disease is fatal in about three to five percent of patients.
Concerns over the disease have badly frightened many Hong Kong residents, and sparked rumors Tuesday that the entire city might be essentially sealed off from international travel. That prompted a run on supermarkets, as frightened consumers grabbed supplies. The government has denied those rumors, saying there are no plans to restrict travel, and urged the public to remain calm.