This document provides information about Severe Acute Respiratory Syndrome (SARS). It defines SARS as a coronavirus that causes severe respiratory illness, sometimes progressing to pneumonia or respiratory failure. The SARS-CoV genome is large for a virus and codes for proteins involved in replication. SARS spreads through respiratory droplets and direct contact, with symptoms like high fever. Diagnosis involves virus detection through cell culture or antibody tests. Treatment includes antivirals and immunomodulators. Prevention relies on promptly detecting, isolating cases and tracing contacts to break transmission chains.

1. Severe Acute Respiratory
Syndrome (SARS)
Presented By: Saira Yasmeen

2. SARS Definition
The SARS coronavirus,
sometimes shortened to SARS-
CoV, is the virus that causes
severe acute respiratory
syndrome
In some cases progressing to
pneumonia and respiratory
failure.

3. Coronaviridae
 A family of largest
RNA viruses known
 enveloped, positive-
sense single
stranded RNA virus.
 CDC classifies the
virus as a select
agent

4. SARS-CoV Genome
 Its genome is about 29.7kb, which is one of
the largest among RNA viruses.
 71% of the genome codes for polyproteins
 Its genome expression starts with translation
of two large ORFs, 1a and 1b, both of which
are polyproteins.
 The functions of several of these proteins
are known. ORFs 1a and 1b are also known
as replicase and transcriptase.

5. SARS-CoV Genome

6. Pathogenesis
 Receptors
 ACE 2
 Surface protein L- sign
 DC - sign
 Induce apoptosis
 Immune cell infection
 Age and sex are contributing factors
 Chemokine and cytokine expression

7. PATHOLOGY
Lungs Liver kidney
spleen Lymphoid
organs
Skeletal
muscles
GIT tract

8. SARS-CoV Life Cycle
 S-protein binds to receptor  initiation of
induced endocytosis
 Translation of viral RNA polymerase
 Transcription of (+) RNA into genomic
and subgenomic mRNA in the cytoplasm
 N protein synthesized from free ribosome
 S and M protein synthesized in RER
 Budding from RER as virion, excretion
from cell via Golgi

10. Clinical Symptoms
High fever

11. Transmission of SARS

12. Transmission of SARS-CoV
 Highly probable: origination is a cross-
species jump from civet cat to human
 Human-to-human transmission
 Direct contact
 Spread in droplets shed from respiratory
secretions
 Possible fecal transmission

13. Methods of Diagnosis

14. Virus Detection
 Virus isolation: inoculate suitable cell
culture with patient specimens

15. Antibody Detection
Serologic Testing: Laboratory test that
searches for antibodies (substances made by
the body's immune system to fight a specific
infection) to the SARS virus in the patient's
blood
 Enzyme-linked immunosorbent assay (ELISA)
 Immunofluorescence assay (IFA):

16. Clinical Findings
 Clinical history & observation
 Chest radiography: important role
 70-80% patients have abnormal chest radiographs
Normal SARS patient

17. Method of Cure

18. Immunomodulatory therapy
 Corticosteroid
 Very powerful: affect entire body
 Anti-inflammatory & immunosuppressive
effects
 Significance: early improvement of fever, better
radiographic infiltrates

19. Antiviral Agents
 Ribavirin: nucleoside analog
 Most frequently administered
 Have antiviral activity against
many DNA & RNA viruses

20. Antiviral Agents
 Protease inhibitor:
 Lopinavir-ritonavir co-formulation: protease
inhibitor used to treat HIV infection
 With ribavirin: block processing of the viral
replicase polyprotein  prevent RNA
replication

21. Method of Prevention &
Control

22. Principle of Disease
Confinement
 Principle: to break the chain of transmission
from infected to healthy person
 3-step protocol of disease confinement
 Case detection
 Prompt isolation
 Contact tracing

Daily health check

Voluntary home isolation

23. THANK YOU