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SARS Cases Worldwide Reported to WHO as of June 6, 2003. Europe: 8 countries (38). Canada (219). U.S. (68). China (5329). Hong Kong (1750). Vietnam (63). SA (2). Taiwan (676). Singapore (206). Thailand (8). Australia&NZ (6). Total: 8404 cases; 779 deaths (~10%case fatality).
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SARS Cases Worldwide Reported to WHO as of June 6, 2003 Europe: 8 countries (38) Canada (219) U.S. (68) China (5329) Hong Kong (1750) Vietnam (63) SA (2) Taiwan (676) Singapore (206) Thailand (8) Australia&NZ (6) Total: 8404 cases; 779 deaths (~10%case fatality)
Masked shop owner in Amoy Gardens complex photo by Christian Keenan
Coronaviruses Single Strand RNA, nonsegmented, enveloped, ~31,000 bps Order: Nidovirales Family: Coronaviridae • Torovirus and Coronavirus :Grp I, Grp II, Grp III • 229E and OC43 in humans cause ~1/3 of common colds , reinfections common • May remain viable for several hours after drying on surfaces
Relative Size of Coronaviruses Compared to Other Microbes NY Times 4/27/03
Structure of Coronavirus Virion - The spikeglycoproteins create corona, bind and fuse with host cell membranes Holmes, NEJM 2003;348: 1948
release attachment entry translation mRNA synthesis maturation assembly replication nucleus M Denison, Vanderbilt
CDC Genome Organization A E 1a 29,727 nt 1b S M N 5,000 10,000 15,000 20,000 25,000 30,000 1 B 20,001 25,000 30,000 X1 E X3 M N S X2 X4 X5 8.3 kb RNA 2 4.5 kb RNA 3 3.4 kb RNA 4 2.5 kb RNA 5 1.7 kb RNA 6 - Replicases (1a/1b) & structural genes (S,E,M,N) - Multiple small genes (X1-X5)-these vary in number, location, and sequence in different coronaviruses
SARS-CoV is similar in general genome organization to other coronaviruses SARS-CoV is genetically distinct from other known coronaviruses • Structural proteins are < 40% identical • Replicase proteins are < 70% identical • SARS-CoV nsps are not homologous to known proteins Specific RT-PCR assays will allow the rapid and sensitive detection of the virus, aiding in control CDC Enterovirus Reference Laboratory
- Distinct from other known coronaviruses • Neither a mutant nor recombinant • Previously unknown, probably from a nonhumanhost, has acquired the ability to infect humans.
Evidence that Urbani Coronavirus is the Etiology of SARS • Culture of novel coronavirus from SARS patients in multiple sites worldwide • Identical Sequence • EM’s from BAL and lung showing coronavirus • PCR finding novel coronavirus nucleic acid • Antibody response specific to novel coronavirus, sera from other human coronaviruses show no reaction • Infection re-produced in primate animal model
CIVET CAT Nocturnal Animal Related To Mongoose Delicacy in Southern China
Probable SARS cases by reported source of infection,* --- Singapore February 25--April 30, 2003 MMWR 2003;52:405 MMWR 2003;52:405