Download SARS

SARS
(Severe Acute Respiratory Syndrome)
“viral pneumonia”
Sejal Patel
December 6th, 2004
Where SARS was first found!
 In a health care worker
 In Guangdong Province, China.
 In November, 2002.
SARS-CoV Urbani strain named
after Dr. Carlo Urbani (WHO)
notified WHO of unusual respiratory
disease in patient (index patient) in
Hanoi.
SARS Taxonomy
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Group IV: Positive Sense
Single Stranded RNA
Order: Nidovirales (“Nested”
viruses)
Family: Coronaviridae
Genus: Coronavirus
Species: SARS coronavirus
(SARS –CoV, Urbani strain)
Hosts: Vertebrates
Courtesy of Dr. Alan Cann.
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©McGraw-Hill, Inc.2005
Scientific Classification
Coronaviridae(s)
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•
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2 genus
1. Coronavirus (SARS-CoV)
* Previously Unknown
2. Torovirus(Equine torovirus)
Pathogenesis proven by Koch’s Postulate on Monkeys
Coronavirus
* healthy masked palm civets (paguma larvata)
* China, Hong Kong, Singapore, Hanoi, and Toronto.
Courtesy of Dr. Alan Cann.
* single stranded RNA (+ssRNA); encodes five major proteins maybe even
more.
* responsible for the death of more than 800 patients in over 27 countries.
Coronavirus Pathogenesis
“The envelope carries three
glycoproteins:
• S - Spike protein: receptor binding,
cell fusion, major antigen
• E - Envelope protein: small,
envelope-associated protein
• M - Membrane protein:
transmembrane - budding &
envelope formation In a few types,
there is a third glycoprotein:
• HE - Haemagglutinin-esterase
Courtesy of Dr. Alan Cann.
The genome is associated with a basic
phosphoprotein, N.”
Coronavirus Pathogenesis cont…,
• enters via endocytosis & membrane fusion
• + sense genome is translated to produce viral
polymerase
• assembled in the golgi apparatus and
transport using secretory nature and released.
•REPLICATION OCCURS IN CYTOPLASM
Courtesy of Dr. Alan Cann
• - sense strand used as a template to produce
mRNA (monocistronic), “nested set” of
transcripts
.
• Viral polymerase produces full length – sense
strand (poorly understood step)
Symptoms and Diagnostic Tests
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Initial Symptoms:
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Week Later:
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dry cough, difficulty breathing and severe diarrhea are seen in patients.
Recovery: starts after 5 to 6 days
Early Diagnosis:
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fever of 100.4о F or higher, headaces, body aches, and malaise.
patient is given antibiotics, antiviral, and steroids used for atypical pneumonia.
Patient is are quarantined in specially ventilated rooms.
Laboratory tests:
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RT-PCR (reverse transcription-polymerase chain reaction) assay
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EIA (enzyme immunoassay)
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Detection of SARS-CoV RNA
Detection of serum antibody to SARS-CoV RNA
Enzyme-linked immunosorbent assays (ELISA)
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Detects antibodies against the virus produced in response to infection
Treatment and Prevention
 No standard treatment yet
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Patients receive combination therapy
 effective antiviral and steroid (Lopinavir/ritonavir plus ribavirin)
Prevention
 Isolation
 Sterilization of area occupied by SARS patients
 Caution and extra precautionary measure taken by medical workers and
doctors.
 Vaccines
 According to the SAVI researchers 3 vaccines are possible to be used in
the future: Whole killed vaccine, adenovirus vector, and recombination
spike protein.( a bit more later in the presentation.)
Epidemiology of SARS
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Animal and environmental reservoirs
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Onset of illness
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Farms: raising and slaughtering of infected animals like unlucky palm civets
Might SARS-CoV recombine with other strains of the coronavirus? NO not likely!
Incubation period: 4 to 6 days
Infectious period is very dangerous if not treated right away leads to death of
infected person/animal
Transmission
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Close contact – droplet, fomites, direct contact
Airborne
Fecal-oral
Latest on Morbidity and Mortality Reports
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“Scientists test blood in Beijing.
China's government announced
that a vaccine for Severe Acute
Respiratory Syndrome (SARS)
had emerged from the first phase
clinical test as both safe and
effective.”2(Right)
“An infrared thermograph system at Tokyo airport.
French airport authorities are planning to experiment
with heat-detecting cameras to identify passengers with
a fever as part of efforts to combat the spread of
infectious diseases, like SARS and bird flu.(AFP/JIJI
Press)”2(Left)
Latest on Morbidity and Mortality Reports
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“SARS Molecular Detection
External Quality assurance:
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Commercial Test kit used
to perform tests on
inactivated severe acute
respiratory syndrome
associated Coronavrius
significantly improved the
outcome. 3
Reference material has
been created for the fist
time in this study which
can be obtained from WHO
(World Health
Organization).3
Figure:" Probity analysis of the fractions of laboratories
achieving a positive result (y-axis) in relation to the virus RNA
concentration in a given positive sample (x-axis). Data points
represent individual samples in proficiency test panel. The thick
line is the regression line calculated on the basis of a probity
model (dose-response curve); the thin lines are 95% confidence
intervals. Data fit into the model with p < 0.0001.”3
At the Present time
“Currently, there is no known SARS transmission anywhere in the world. The
most recent human cases of SARS-CoV infection were reported in China
in April 2004 in an outbreak resulting from laboratory-acquired infections
(see link for more details). CDC and its partners, including the World
Health Organization, continue to monitor the SARS situation globally.”CDC
QUESTIONS!!!!!!
References
1.
2.
3.
4.
“Consensus document on the epidemiology of severe acute respiratory syndrome (SARS).” World Health Organization 2003.,
http://www.who.int/csr/sars/en/WHOconsensus.pdf ., December 5, 2004.
“China says first SARS vaccine ‘safe and effective’” agence France presse. 2004.
http://news.yahoo.com/news?tmpl=story&cid=1508&u=/afp/20041205/hl_afp/health_sars_china., December 5, 2004.
Dorsten. C., Doerr. H., Lim. W., Stohr. K., Niedrig. M., “SARS Molecular Detection External Quality Assurance.” Emerging
Infectious Diseases Vol. 10, No. 12, December 2004. http://www.cdc.gov/ncidod/EID/vol10no12/04-0416.htm
“Current SARS Situation” Centers for Disease Control and Prevention 2004 http://www.cdc.gov/ncidod/sars/situation.htm.,
December 5, 2004.
5.
Prescott. L., Harley.J., Klein. D, “Microbiology” McGraw Hill Inc 2005
6.
Dr. Alan Cann, “Coronaviruses” Microbiology & Immunology. 2004 http://www-micro.msb.le.ac.uk/3035/Coronaviruses.html.
7.
8.
“Public Health Guidance for Community-Level Preparedness and Response to Severe Acute Respiratory Syndrome (SARS)
Version 2” Centers for Disease Control and Prevention, January 8, 2004.
http://www.cdc.gov/ncidod/sars/guidance/F/app7.htm.
“Map of Guangdong.” Muztagh Travel, 2000. http://www.muztagh.com/map-of-china/map-guangdong.htm., December 4,
2004.