Verigene® Respiratory Virus Nucleic Acid TestSP (RVNATSP)
Overview
- FDA-Cleared
- Sample-to-result automation
- CLIA "Moderately Complex" designation
- On-demand, random access testing
- Scalable workflow
- "Detected" or "Not Detected" results for 3 common respiratory viruses in a single test cartridge:
- Influenza A (reactive with 2009 H1N1 cultured isolates*)
- Influenza B
- RSV A/B

Background
Each year in the United States, nearly 12 million patients present to emergency departments with respiratory illnesses1. The two leading causes of respiratory illness are infection with influenza or respiratory syncytial virus (RSV). Most patients with these infections can be safely discharged with little or no treatment, however, as many as 325,000 will need to be admitted for further care (primarily the young, elderly, and otherwise immunocompromised patients)2,3. In a hospital setting, influenza and RSV outbreaks can be catastrophic, as both pathogens are highly contagious. Consequently, the rapid identification of patients infected with these viruses has become a focus of busy emergency departments, clinical laboratories, and medical centers as a whole. Rapid antigen tests are capable of detecting respiratory viruses in less than 30 minutes. However, the sensitivity of these tests can be as low as 10% in the clinical setting4. RT-PCR tests, on the other hand, have demonstrated excellent sensitivity, but the complexity of these tests has prevented many laboratories from offering them.
Influenza
The influenza virus is a contagious respiratory pathogen known to cause mild to severe illness in people of all ages. Influenza type A is the most common type of seasonal influenza, and can also cause non-seasonal epidemics. The other major type of influenza, type B, is less common and generally leads to milder disease. Seasonal influenza occurs primarily in the fall, winter, and early spring, and will infect 5% to 20% of the population in a given year5. In the United States, influenza infections are responsible for over 200,000 hospitalizations and 36,000 deaths each year. Symptoms include fever, headache, congestion, and general malaise. Influenza can also lead to serious complications, such as pneumonia, bronchitis, sinus infections, and encephalitis.
RSV
Respiratory syncytial virus can cause upper and lower respiratory tract infections in children and, less commonly, in adults with weakened immune systems. It is the leading cause of bronchiolitis and pneumonia in children under one year of age in the United States6, and leads to between 75,000 and 125,000 hospitalizations each year2. Similar to influenza, RSV outbreaks occur seasonally in the US in the fall, winter, and early spring. Symptoms include coughing, sneezing, runny nose, fever, and decrease in appetite.
Performance Characteristics – Semi-Automated Test
The Verigene® Respiratory Virus Nucleic Acid Test (VRNAT)‡ is a semi-automated predecessor to the automated Verigene® Respiratory Virus Nucleic Acid TestSP (RVNATSP). The test combines external nucleic acid extraction and RT-PCR with Nanosphere's proprietary nanoparticle hybridization technology for detection and identification of Influenza A, Influenza B, and RSV on the Verigene® System.
Table 1 - VRNAT vs Culture/DFA with Bi-Directional Sequencing for Discordant Results7
| VRNAT vs Culture/DFA | VRNAT vs Culture/DFA with Bi-Directional Sequencing for Discordant Results | |||
| Sensitivity | Specificity | Sensitivity | Specificity | |
| Influenza A | 99.2% | 90.1% | 100% | 99.8% |
| Influenza B | 96.8% | 98.5% | 100% | 99.1% |
| RSV | 89.8% | 91.5% | 95.7% | 98.2% |
VRNAT performance versus culture/DFA and bi-directional sequencing (to resolve discordant results) for 720 nasopharyngeal specimens. See package insert for detailed information of discordant analysis and other performance characteristics.
Performance Characteristics - Verigene® RVNATSP
The Verigene® RVNATSP is an automated version of the semi-automated VRNAT assay. It utilizes the new Verigene® Processor SP (Figure 1) to automate sample preparation and test processing. This FDA-cleared test requires only one user pipetting step and less than 5 minutes of hands-on time for a sample-to-result turnaround time of about 3.5 hours. A method comparison was performed to demonstrate equivalency between the automated Verigene® RVNATSP and semi-automated VRNAT tests.
Table 2 - Verigene® RVNATSP vs VRNAT Method Comparison8
| VRNAT (Semi-Automated) | |||||
| Positive | Negative | Total | |||
| Verigene® RVNATSP (Automated) | Positive | 191 | 0 | 191 | PPA 97.9% (95% CI=94.8%-99.0%) |
| Negative | 4a | 363 | 367 | NPA 100.0% (95%CI=99.0% - 100.0%) |
|
| Total | 195 | 363 | 558 | ||
Method comparison of automated Verigene® RVNATSP vs semi-automated VRNAT using 62 unique samples run at three separate sites. The 62 samples provided a total of 186 decisions, as each test delivered a 'Detected' or 'Not Detected' result for each of the 3 viruses: Influenza A, Influenza B, and RSV. Of the 62 samples, 3 samples had dual infections where 2 viruses were present. See package insert for detailed performance characteristics.
Ordering Information
The Verigene® RVNATSP is now available as an FDA-cleared product For in vitro Diagnostic Use. For more information on ordering or to arrange a system demonstration please contact Nanosphere at 1-888-VERIGENE (837-4436) or IDtesting@nanosphere.us.Coming Soon
Nanosphere is working hard to deliver a broad menu of innovative clinical microbiology and infectious disease tests for use on the Verigene® System. For more information on influenza A subtyping (in development), expanded respiratory virus panel (in development), and rapid bloodstream infection ID (in development) tests, please contact Nanosphere at IDtesting@nanosphere.us.Literature Cited
- Centers for Disease Control and Prevention. National Hospital Ambulatory Medical Care Survey: 2006 Emergency Department Summary, 2006. National Health Statistics Reports: Number 7; August 6, 2008.
- Shay DK, Holman RC, Newman RD, Liu LL, Stout JW, Anderson LJ. Bronchiolitis-associated hospitalizations among U.S. children, 1980--1996. JAMA 1999;282:1440-6.
- Centers for Disease Control and Prevention. Seasonal Influenza-Associated Hospitalizations in the United States. Reviewed September 18, 2006. Retrieved June 23, 2009 from www.cdc.gov/flu/about/qa/hospital.htm.
- Hurt AC, Alexander R, Hibbert J, Deed N, Barr IG. Performance of six influenza rapid tests in detecting human influenza in clinical specimens. J Clin Virol 2007; 39:132-5.
- Centers for Disease Control and Prevention. Key Facts About Seasonal Influenza (Flu). Reviewed March 12, 2009. Retrieved June 24, 2009 from www.cdc.gov/flu/keyfacts.htm.
- Centers for Disease Control and Prevention. Respiratory Syncytial Virus Infection (RSV): Infection and Incidence. Reviewed October 17, 2008. Retrieved June 24, 2009 from www.cdc.gov/rsv/about/infection.html.
- Jannetto PJ, Vaughan K, Prokhorova A, Brener D, Lonosky PM, Sonpatki VM, Marla SS, Cork WH, Guaring-Angulo N, Pathak N, Saad R, Ledeboer NA. Nanoparticle probes for the detection and discrimination of influenza A/B and RSV A/B in respiratory specimens, abstract M10. 2009; 25th Clinical Virology Symposium, April 19-22, Daytona Beach, FL.
- Verigene® Respiratory Virus Nucleic Acid TestSP Package Insert.