In the last seven days, Chinese figures have shown fewer than 10 new cases a day, a sharp decrease from the average 500 cases a week the country has reported since March.
“We are concerned about how these cases are being counted,” WHO spokesman Ian Simpson said. “We do not know enough about where these numbers are coming from.”
On Tuesday, Chinese officials announced only three new SARS cases, two of them in Beijing, the world’s hardest-hit city. The report represented one of the lowest daily tolls since the disease first was reported.
“It may simply be that there has been a dramatic drop off in the number of SARS cases, but clearly because of the way that SARS emerged in China, China has a credibility problem,” Simpson said.
China has been criticized for waiting four months before informing the WHO about the outbreak of the illness late last year. In April, a Chinese doctor accused his country’s officials of covering up details about the number of SARS cases in Beijing.
SARS has been shown to kill some 15 percent of its victims, including young and healthy people. Officials believe the disease originated in China’s Guangdong province in early November 2002. Since then, the virus has infected more than 5,300 Chinese people and killed 334.
Worldwide, some 8,384 people have been infected with SARS and 770 have died.
People infected with SARS spread the virus by coughing or sneezing droplets of fluid into the air. Those in close proximity to the SARS carrier breathe in the droplets and can get sick.
Part of the WHO’s concern that China may not be counting all its SARS patients stems from the need to aggressively identify victims and isolate them in order to help curb the spread of the disease.
The virus causes flu-like symptoms including fever, chills, headaches and body aches, and, in some cases, patients suffering from the illness reported having serious difficulty breathing.