SYDNEY, Australia -- Sydney's water contamination crisis -- its second in a month -- worsened today, with authorities extending health warnings and urging residents to boil tap water before drinking it.
Organizers of the 2000 Olympics in Sydney said the scare threatened to taint the city's international reputation.
Test results have varied widely. Late Thursday, they showed extremely high levels of the dangerous parasites cryptosporidium and giardia. Tests today, however, showed no signs of either, said Michael Reid, director-general of the New South Wales state health department.
Health warnings will not be lifted until a series of tests shows the water is safe.
No illnesses have been reported as a result of this or the outbreak in July, in which both cryptosporidium and giardia levels were recorded at dangerous levels.
Reid said health warnings had been extended to cover areas previously thought to be safe, forcing almost all of the city's 3.7 million residents to boil tap water for drinking, cleaning teeth, gargling, washing foods and making ice.
After Sydney's water scare in late July, Sydney's main water treatment plant was flushed out.
Sydney Olympics chief executive Sandy Holloway said the city was being closely watched internationally because of the upcoming games, and the problem needed to be fixed quickly and permanently.
"We are on show. For the water scare to happen once ... could be dismissed as a quirky aberration," Holloway said. But "were this to happen periodically between now and the Games, this would dent our image."
An inquiry into the outbreak is under way. Authorities have blamed it on heavy rainfall in the Sydney area in recent weeks.
Giardia, normally spread through human or animal fecal matter, can cause diarrhea and other gastrointestinal problems. Cryptosporidium causes flu-like symptoms and can kill people with weak immune systems, including the very young and the elderly.
Cryptosporidium got into the water supply of Milwaukee, Wis., in 1993, killing about 100 people. More than 400,000 others were sickened.