Chinese scientists on Friday announced a breakthrough in
decoding the evolutionary pattern of the coronavirus, which caused
the worldwide outbreak of severe acute respiratory syndrome (SARS)
last year.
Zhao Guoping, a noted researcher from the China National Human
Genome Research Institute, said in Guangzhou Friday that an
eight-month extensive study of the SARS coronavirus in south China
revealed patterns in various phases of the virus evolution.
Molecular analysis of virus isolated from SARS patients in Guangdong
Province and the Hong Kong Special Administrative Region
(HKSAR) demonstrated the initial phase of the epidemic was
characterized by quick amino acid changes in the virus and
relatively low infectivity.
The middle phase of virus evolution was marked by the
"super-spreader case" and a slower amino acid substitution rate and
high infectivity. The last phase of the epidemic saw a relatively
stable virus genome structure.
The study also indicated the mutation rate of the coronavirus is
a third of that of the AIDS virus.
Scientists analyzed the genetic coding of 18 virus samples
isolated from 24 SARS patients in Guangdong Province and the HKSAR
and 11 coronavirus-infected biological samples.
After comparing the genetic coding with those of the existing 32
human SARS coronavirus and two coronavirus of civet cats,
scientists had a clearer understanding of the molecular mutational
patterns of SARS, shedding light on pre-emptive control strategies
and the development of therapies and vaccines for the virus,
according to experts.
More than 60 scientists from Guangdong, Shanghai, Beijing,
Wuhan, Hong Kong and the United States, assembled by the Chinese
SARS Molecular Epidemiology Consortium, agreed that effective
monitoring and control of the newly emerged animal SARS coronavirus
would contain the reappearance of last year's SARS outbreak.
The study is also widely expected to provide valuable reference
for studies on other animal-sourced infectious diseases such as the
bird flu.
The Jan. 29 issue of Science Magazine in the US published
the latest outcome under the title The Evolution of SARS.
(Xinhua News Agency January 31, 2004)