SARS Coronavirus Detection

1
SARS Coronavirus Detection

• Karen K. Y. Young, Ph.D.
• Roche Molecular Diagnostics
• Thomas Emrich, Ph.D.
• Roche Applied Sciences

2
Critical Issues

• Logistical challenges
• Nature of epidemic not well understood
• Seasonal?
• Reservoir?
• For rapid introduction of diagnostic assay
• Need to mobilize resources quickly
• Need partnership with regulatory agencies
• Sample acquisition
• IP landscape

3
Critical Issues

• Technical challenges
• Optimal sample type?
• Blood/serum/plasma
• Respiratory specimen
• Stool/urine
• Sample preparation issues
• Removal of inhibitors
• Efficient lysis/preservation of RNA
• Viral sequence heterogeneity
• Mutation
• Recombination
• Standardization/reference material

4
Roches Response

• Rapid development of research assay
• Quantitative real-time PCR
• LightCycler
• Sample preparation defined by user
• Development of IVD assay if warranted
• Regulatory guidance needed for performance
  requirements
• Lessons learned from research assay
• Automated sample preparation
• TaqMan PCR
• Full-process controls

5
Research Assay Status

• LightCycler-based assay
• Real-time PCR
• Quantitative, external calibration standards
• Internal control
• User-defined sample preparation
• In-house evaluation of positive samples completed
• World-wide trial at beta sites on-going

6
Research Assay Performance

• In-house evaluation
• Positive samples from Hong Kong (N40)
• Sample types
• Nasal-pharyngeal aspirates
• Stool
• Urine
• Throat swabs

7
Research Assay PerformanceIn-house evaluation
8
Challenges to SARS diagnosis

• Many unknowns
• Nature of epidemic?
• Natural history of infection?
• Most appropriate sample type?
• Optimal sample handling?

9
Challenges to SARS diagnosis

• To effect rapid introduction of diagnostic assay
• Requires dedicated resources
• Co-operation from regulatory/public health
  agencies needed
• Definition of performance requirements
• Standardization for assessment of assay
  performance
• Availability of reference standards
• Availability of clinical samples for assay
  development and evaluation