SARS could still re-emerge and could be easily misdiagnosed, according to medical experts.

More than 800 doctors and scientists from the Chinese mainland, Hong Kong and Macao participated in a two-day symposium on the prevention, diagnosis and treatment of SARS (severe acute respiratory syndrome) in Guangzhou over the weekend.

Experts said it was still hard to diagnose SARS and suggested more than one test to decide whether a suspected patient has contracted the disease.

Yang Zhicong, deputy-director of Guangzhou Municipal Disease Control Centre, has recommended people receive the anti-flu vaccine to reduce the chance of flu symptoms being mistaken for SARS. Chen Wensheng, a Guangzhou-based expert, believes a flu outbreak is likely in South China this year.

The vaccine will also be used in Beijing, Shanghai and other big cities across China.

However, SARS could reappear, according to Ni Daxin, an expert with the China Disease Control Centre.

A recent SARS diagnosis in a 27-year-old postgraduate student in Singapore has increased people's vigilance globally.

The World Health Organization (WHO) announced on Wednesday it was safe to travel to Singapore, reducing the potential for panic.

Ni said there should be no need for alarm if effective measures are taken to prevent and control the spread of the disease.

Zhong Nanshan, an expert in respiratory disease and scholar with the Chinese Academy of Engineering, said great progress had been made by provincial scientists in search for a vaccine against SARS. But prototypes have not yet been tested on people.

"The vaccine will be tested on people, in case the disease reappears,'' said Zhong. He is leading research into and development of two vaccines, a serum-related one and a nose-drop one.

According to Zhong, the most urgent task is to adopt a multi-test method to improve the correct diagnosis rate for SARS.

Of the 1,274 reported SARS cases in Guangdong in the first half of this year, only 892 cases were later proven to have SARS. The rest had other respiratory diseases with symptoms similar to SARS.

"It adds to the difficulty of our work,'' said Zhong.

However, he said the tracking of 43 former SARS patients showed 93 per cent recovered normal lung function.

"They could be immune from the virus for six months,'' he said.

The symposium participants explored various theories related to SARS, such as those on airborne transmission, environmental influences, psychology and family epidemics.

In the first half of this year, SARS killed more than 900 people and sickened about 8,400 worldwide.

(People's Daily   September 15, 2003)