Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
This is qualitative PCR assay used to detect DNA or RNA from respiratory viruses in patients with respiratory symptoms. The standard screen for most patients includes SARS-COV-2, Influenza A, Influenza B and RSV. For patients who are immunocompromised or require intensive case an ‘Extended viral respiratory screen’ can be ordered if indicated. The extended test can additionally detect Parainfluenzavirus 1 – 4, Metapneumovirus, Adenovirus and Rhinovirus. Where upper respiratory samples are negative and the patient has predominantly lower respiratory symptoms, consideration should be given to sending an induced sputum or BAL.
It should be noted that PCR may remain positive for several weeks after infection. The detection of viral DNA or RNA does not necessarily equate with ongoing viral replication and infectious virus. In certain cases a wider respiratory pathogen PCR may be indicated, with additional viral and atypical bacterial targets, including mycoplasma pneumonia, this should be discussed with a microbiologist or virologist.
Specimen container paediatric:
Upper respiratory tract swab/secretions (nose/throat/nasopharyngeal) in viral transport medium/saline.
Lower respiratory tract sample if available (Sputum, ETA or BAL), tissue.
Specimen container adult:
Upper respiratory tract swab/secretions (nose/throat/nasopharyngeal) in viral transport medium/saline.
Lower respiratory tract sample if available (Sputum, ETA or BAL), tissue.
Minimum volume paediatric:
- 2ml respiratory secretions
- 1 Swab from site
Minimum volume adult:
- 2ml respiratory secretions
- 1 Swab from site
Special requirements:
Send to laboratory as quickly as possible. If delays likely, refrigerate at 2-8 deg C.
Sample stability:
Stable for up to 24 hours
Transport requirements:
Standard
Add on test:
Possible up to 6 days
Quality assurance:
UK National External Quality Assurance Scheme (UKNEQAS).
Interpretation:
N/A
Referenced Ranges:
None available
Factors Affecting Result:
If delays likely, refrigerate at 2-8 deg C
Referenced documents:
Standards of Microbiology Investigations (SMI S 2)
Other info:
N/A