BEST PRACTICES FOR SAMPLE COLLECTION FOR RESPIRATORY SPECIMENS, INCLUDING NOVEL CORONAVIRUS (COVID-19) POINTS TO N-PAK
With the current rise in flu cases and possible spread of emerging respiratory viruses, like the novel coronavirus (COVID-19), laboratories and healthcare providers can expect another very busy season. The 2019-2020 flu season is on track to be one of the worst in years and is estimated to be similar in severity to the 2017-2018 flu season. By the end of that 2017–2018 season, the Centers for Disease Control (CDC) reported that the total burden of illness showed an estimated 48.8 million people became ill with influenza, 22.7 million people visited a health care provider, there were 959,000 hospitalizations, and 79,400 fatalities.
New data from the CDC estimates at least 6.4 million people have already acquired the flu so far this season. Over 55,000 people have been hospitalized, and 2,900 people have died. With a severe flu season upon us and the possible emergence of other respiratory viruses, like the novel coronavirus (2019-nCoV), it is essential to revisit the topic of respiratory virus detection and consider the best methods for sample collection and transport for testing.
Accurate respiratory virus detection is dependent on the quality of the sampling method, storage, and transportation to the testing site. A successful diagnostic test begins at sample collection because improper sampling can result in an inadequate specimen, rendering a diagnostic test inconclusive or incorrect. There are several upper respiratory tract sampling methods currently being utilized prior to testing, including nasopharyngeal aspirates/washes, nasal washes, and a combination of synthetic swabs.
The article “Current Best Practices for Respiratory Virus Testing” published in the Journal of Clinical Microbiology, by Christine Ginocchio and Alexander MacAdam, considers issues in diagnostic testing for respiratory viruses, including best methods for detection, sample handling and testing for antiviral resistance. It is as relevant today as it was in 2011 when it was first published. This like other studies before and after demonstrates the superior sensitivities of nasopharyngeal wash/aspirate over NP swab and oral swab.
As testing methods evolve, it is important for clinicians to keep current with the techniques like those outlined in the best practice article. Specimen collection should be performed by health care personnel who have completed training and demonstrated competency. Use of N-Pak has proven easier to perform and more acceptable by patients than NP swab. With higher sensitivities, NP aspiration has been the gold standard for respiratory viral testing. Given the virulence of Covid-19, maximizing sensitivities is of utmost importance. Given N-Pak is a non-aerosol-generating method of NP aspiration and it’s degree of discomfort it is the perfect method to obtain a nasal and pharyngeal sample load. Given the knowledge of Covid-19 sample experience in China as depicted in the article by Wenling, Detection of SARS-CoV-2 in Different Types of Clinical Specimens , the need for nasal and pharyngeal sampling is likely recommended to maximize the viral load for diagnosis. As most NP swabs rarely get to the nasopharynx, NP aspirates will likely continue to demonstrate improved sensitivities as further evaluation and knowledge is gained in sampling and detection of Covid-19.
It is important to follow the CDC recommendations regarding specimen collection and transport for the type of test kit being used. This is very important in regards to Covid-19 Interim Guidelines for Collecting, Handling, and Testing Clinical Specimens for Coronavirus investigations. N-Pak is specifically referenced as the technique of choice for NP aspiration as noted on the CDC demonstration video. This video properly demonstrates the NP aspiration technique for pertussis and viral pathogens utilizing N-pak in its instructive video.
The performance of a diagnostic test starts with sound sampling techniques and the quality of the specimen collection. Having an appropriate and less invasive collection enables healthcare professionals to better care for sick patients, while ensuring the integrity of the sample provided to the laboratory. As we continue to fight the Corona virus and other concerning viral pathogens, N-Pak will provide for specimen collections with high sensitivity in diagnostic testing for Covid-19, influenza, RSV, and other respiratory infections, whether using culture, antigen, or molecular assays.