The SARS virus can live for up to 15 days outside the human body, Chinese scientists have discovered.
The key Science and Technology Group under the National Task Force for SARS Control and Prevention yesterday revealed that the virus can exist in temperatures of 24 C for five days in patients' saliva, mucus and excrement, 10 days in urine and 15 days in blood.
It can live indoors for three days on paper, cotton cloth, wood, metal, plastic and glass surfaces and in soil.
But scientists have also found that a disinfectant that contains chlorines and peroxide acetic acid recommended by the Ministry of Health can kill the SARS bug in excrement and urine in several minutes.
Another way of eradicating the virus is to irradiate it.
Experiments indicate that the lifespan of SARS reduces as temperatures rise. In normal conditions, the virus can exist for four days if temperatures are less than 37 C, 90 minutes at under 56 C and 30 minutes at under 75 C.
Huang Peitang, the group's deputy director, said scientific research proves that SARS patients who have been discharged from hospitals after recovery are not infectious. This conclusion was based on tests of mouth-rinsing water, samples of excrement and serum from 100 recovered patients, said Huang.
Huang said the science and technology group will provide laboratory testing services to prove SARS survivors are virus-free.
Recovered patients are welcome to give serum and other samples by calling a hotline under the China Diseases Control and Prevention Center: 010-61739580.
"This service will benefit recovered patients as well as their families, relatives and friends," said Huang.
He said preliminary studies show that the possibility of SARS infection during the symptom-free incubation period is very small.
Scientists have also made short and medium-term SARS forecasts. They previously predicted that Beijing would have no more than 2,600-2,800 confirmed SARS patients by the end of May.
Ministry of Health statistics put the figure as of 10 am yesterday at 2,522.
The number of new patients hospitalized during the first week this month is likely to be less than five.
Li Xueyong, the group's vice-director as well as vice-minister of Science and Technology, said care is still needed, given that SARS is not yet completely controlled.
He said the group will concentrate more on developing vaccines as well as more effective medicines and clinical treatment technology.
Work is under way to better preserve viral and other samples, and to protect intellectual property developed during SARS studies.
(China Daily June 3, 2003)
