A new outbreak of SARS (Severe Acute Respiratory Syndrome) was caused by a laboratory infection, officials say.

As early warning systems for SARS kicked into gear across the country, two cases have been confirmed and two are suspected in Beijing and east China's Anhui Province. One person has died.

The silver lining, say health experts, is the fact that the virus comes from a laboratory which reduces the risk of people being infected.

"We have adopted effective measures to prevent the spread of the virus. SARS cases in Beijing will not influence any visit from overseas," Jin Dapeng, director of the Beijing Municipal Bureau of Health vowed yesterday.

However, as of Friday, a total of 305 people, 188 in Beijing and 117 in East China's Anhui Province, who may have had close contact with the four cases, have been identified and put under medical observation.

Moreover, six of those, five in Beijing and one in Anhui, have shown some SARS symptoms, such as fever.

A 20-year-old nurse surnamed Li was the first reported case on Thursday but she was not the first person infected, officials said Friday.

Instead a 26-year-old woman surnamed Song, has been confirmed as the first person infected by the virus.

Song is a graduate student at Anhui Medical College, in East China's Anhui Province, and has been studied at the laboratory of the Virus Disease Control and Prevention Institute of the Chinese Centre for Disease Control and Prevention between March 7 and 22.

She returned to Hefei, the capital of Anhui, by train on March 23, and had a fever and other symptoms on March 25.

Song then traveled to Beijing by train and was hospitalized after being diagnosed with pneumonia at Li's hospital on March 29.

She returned to Anhui on April 2.

Li looked after Song while she was in hospital and was likely infected by her, officials said.

Song continued her treatment for a viral pneumonia at the No.1 Affiliated Hospital of Anhui Medical College on April 4.

Song's mother, who accompanied with her since March 31, developed a fever and checked into the same hospital on April 8. She died on April 19. Doctors had not been able to identify that type of pneumonia she suffered from.

Warning system into gear

However, the mother's death spurred local health authorities to put in place the SARS warning system.

After the strict tests by local and national CDCs between April 21 and yesterday morning, Song was confirmed as a SARS case.

Her mother, who has passed away, was declared a suspected SARS case.

Another suspected SARS case, a 31-year-old man surnamed Yang, is a postdoctoral student at the same laboratory where Song studied.

He become ill on April 17 and was checked into Beijing's Ditan Hospital on Thursday.

The fact that both Song and Yang had access to the same laboratory, has led experts to believe that this outbreak was caused by a laboratory infection. However, officials have not revealed whether the laboratory deals with the SARS virus.

The institute and the laboratory have been isolated, and experts are doing further test there to search for the source of the epidemic.

Meanwhile, measures have been taken to deal with possible spread caused by Song's train travels between Beijing and Hefei after she become infected.

"Local health authorities along the railway line, by which Song's train passed, have been asked to report any information of all the patients with fever and pneumonia with unknown causes before April 26," said Mao Qun'an, spokesman of the Ministry of Health.

The railway line connects Beijing, Tianjin, Shandong, Hebei, Henan and Anhui.

At the same time, the ministry immediately switched on its nationwide monitoring system, and asked followers in various regions to strengthen the surveillance, especially on patients with fever.

Meanwhile, the World Health Organization (WHO) says the measures taken by local authorities may help prevent the spread of the virus.

The reporting and measures taken by China against the new SARS outbreak are timely and effective, officials from the Beijing Office of the World Health Organization were quoted as saying Friday.

Su Juxiang, secretary-general of the Red Cross Society of China, sent a letter to the Red Cross Organization of Taiwan early Friday, briefing them about the SARS outbreaks in Beijing and Anhui Province.

China's State Administration of Quality Supervision, Inspection and Quarantine has issued an emergency circular calling for immediate operation of the monitoring and prevention mechanism against SARS.

According to the circular, border quarantine departments should take strict measures, and anyone found at the border to have a body temperature above 38 degrees Celsius should be sent to hospital for further checkups and treatment.

(Xinhua News Agency April 24, 2004)