Specimen Required

NOTE: If the patient/client has excessive mucus please ask the patient/client to blow their nose to clear nasal passage of excessive mucus. Have the person dispose of the used tissue in a waste receptacle.

All swabs must be transported in Universal Transport
Medium (UTM) to retain viability.

Ensure collection of adequate cellular material.

Specimen Minimum Volume

Liquid: 2 ml

Transport Temperature

Maintain at 2-8^°C and transport (cold packs) within 24 hours.

*For > 24h delay, freeze at -70^°C and transport on dry ice.

Reject Due To

Useful For

Detection of respiratory viruses causing upper- or lower respiratory tract infections.

Clinical Information

Most acute respiratory illnesses are caused by respiratory viruses and involve the upper airways, clinically manifesting as “colds”, pharyngitis, or tonsillitis. Upper respiratory tract illnesses (URTI) are usually self-limited and relatively mild but prompt many physician visits. The influenza like illness (ILI) and viral lower respiratory tract illness (LRTI) such as croup, bronchiolitis, and pneumonia are less frequent but associated with higher hospitalization rates and fatalities. Virus-triggered exacerbations of asthma or chronic obstructive pulmonary disease (COPD) can likewise be severe and sometimes fatal.

Relative importance of major respiratory viruses in upper and lower respiratory tract infections

¹ Respiratory syncytial virus

² Human metapneumovirus

Adapted from Robinson, C. Respiratory viruses

In countries with definite winters, annual epidemics of RSV, influenza virus, hMPV occur with reasonable regularity during the coolers months of the year. Influenza virus tends to produce short annual peak of respiratory illness lasting 6 – 8 weeks, whereas the peak of RSV tends to be broader with a median duration of 15 weeks. hMPV can be detected year-round but usually peak in late winter to spring, coincident with or slightly later than RSV.

Interpretation

Reference

Rhee, E. G., and Barouch, D. H. 2010. Adenoviruses, p. 2027-2033. In Mandell, D., Bennett, J. E., and Dolin, R. 2010. Principles and practice of infectious diseases, 7^th ed., vol. 2. Churchill Livingstone, Elsevier, Philadelphia, PA.

Robinson, C., and Echavarria, M. 2007. Adenoviruses, p. 1589-1600. In Murray, P. R., Baron, E. J., Jorgensen, J. H., Landry, M. L., and Pfaller, M. A. Manual of Clinical Microbiology, 9^th ed., vol. 2. ASM Press, American Society for Microbiology, Washington, DC.

Direct Fluorescent Antigen (DFA)
Microscopy for Emergency Room and In-patients

Culture (Rapid Shell Vial)

Method Description

Direct Fluorescent Antigen Microscopy uses viral antigen-specific murine monoclonal antibodies that are directly labeled with fluorescein for the rapid detection and identification of 8 respiratory viruses targeting influenza A, influenza B, human parainfluenza 1 – 3, respiratory syncytial virus, human metapneumovirus and adenovirus.

Culture and isolation of adenoviruses from clinical specimens is accomplished employing the shell vial rapid culture technique with a mixed monolayer comprising A549 and MDCK cell lines. Shell vials are read at 24- and 48h.

Real-time polymerase chain reaction (PCR) targeting influenza A and influenza B virus matrix (M) gene employing Roche LightCycler® 480.

Performing Laboratory Location

Newfoundland & Labrador Public Health Laboratory

St. John’s