COVID-19 Surveillance Testing

FAQs

• What is the difference between surveillance and diagnostic testing?

  Diagnostic testing looks for occurrence of COVID-19 at the individual level when there is a reason to believe an individual may be infected. Surveillance testing looks for infection within a population or community, and can be used for making health management decisions at the population level^{1US Food & Drug Administration. FAQs on Testing for SARS-CoV-2. FDA. 2020 Sept 24 [Cited 2020, September 25].}.

  For example, if routine COVID-19 surveillance reveals the presence of infection in a workplace population, management might refer individuals for diagnostic testing^{1Centers for Medicare & Medicaid Services. University Lab Testing. CMS. 2020 Aug 28 [Cited 2020 Dec 21].} to determine who is infected, and could even elect to close a facility pending diagnostic test results to prevent further spread.

• Can this kit be used for diagnostic testing?

  No. Chai’s COVID-19 Surveillance Test Kit is marketed for surveillance and research use only. It is not for use in diagnostic procedures. Individual results may not be returned to the tested population^{1US Food & Drug Administration. FAQs on Testing for SARS-CoV-2. FDA. 2020 Sept 24 [Cited 2020, September 25].}. To prevent obtaining individual results in the first place, it is recommended to pool samples. Sample pooling also increases the capacity and speed of testing efforts and reduces costs.

  For diagnostic testing, see our COVID-19 Saliva Dx Test Kit.

• Is CLIA certification required to perform SARS-CoV-2 surveillance?

  No. The US Centers for Medicare & Medicaid Services has stated that facilities using a pooled sampling procedure to report non patient-specific results do not require CLIA certification during the Public Health Emergency^{1US Centers for Medicare & Medicaid Services. Frequently Asked Questions: SARS-CoV-2 Surveillance Testing. US CMS. 2020 [Cited 2020, September 25].}. The pooling feature of our COVID-19 Surveillance Test Kit is designed to allow facilities without CLIA certificates to meet this requirement.

• Can this assay detect Omicron, Delta, and other variants of SARS-CoV-2?

  Yes, as of June 10, 2022, we’ve performed BLAST analysis of available whole genome sequences, and the assay’s ability to detect all current WHO variants of concern, including Delta and Omicron BA.1, BA.2, BA.3, BA.4, and BA.5 sublineages is unaffected.

  The SARS-CoV-2 virus is constantly mutating as it spreads globally. We monitor sequences published to scientific databases such as GISAID on a regular basis and will update this FAQ as appropriate.

• How often should I conduct COVID surveillance testing?

  Most customers test twice a week. Testing at least 2 times per week allows you to detect COVID-19 in its earliest stages of infection with minimal cost and disruption to your school or workplace. As test results are representative of only the specific time of test, testing frequency is an important consideration for detecting infection. A sporadic testing regimen could lead to undetected infections in a population. Even testing once a week allows you to detect and slow the spread of COVID compared to no testing effort at all.

• How do RT-qPCR and rapid antigen tests compare?

  RT-qPCR, or reverse-transcription quantitative polymerase chain reaction, provides accurate, quantitative results within hours. It is the current gold standard method to test for SARS-CoV-2 infection due to it’s high sensitivity. RT-qPCR can detect a miniscule amount of RNA, specific to the pathogen, and make exponential copies of it until there are over one billion copies of that particular RNA segment. This is why RT-qPCR is able to detect an infection at earlier stages, even when viral loads are low. Chai’s COVID Surveillance solution can detect an infection with as little as 5.8 viral copies per microliter of saliva.

  Rapid antigen tests can provide results faster than RT-qPCR but at the expense of accuracy and sensitivity. Rapid antigen tests detect proteins on the surface of the virus, yielding qualitative results that heavily depend on higher viral loads for detection. Compared to RT-qPCR, antigen tests need a sample to contain thousands, or even tens of thousands, of viral particles per microliter to produce a positive result^{1Larremore DB, Wilder B, Lester E, Shehata S, Burke JM, Hay JA et al. Test sensitivity is secondary to frequency and turnaround time for COVID-19 surveillance. medRxiv [Preprint]. 2020 [cited 2020 September 25].}. In cases where the sample has low amounts of virus, rapid antigen tests may be unable to detect a COVID infection and give a false-negative result.

  Multiple studies, including guidance by the CDC, concur that the sensitivity of rapid antigen tests are significantly lower than RT-qPCR^{1Centers for Disease Control and Prevention Interim Guidance for Rapid Antigen Testing for SARS-CoV-2. CDC. 2020 Sept 5 [Cited 2020, September 25].}. One study^{1Mak GC, Cheng PK, Lau SS, Wong KK, Lau CS, Lam ET et al. Evaluation of rapid antigen test for detection of SARS-CoV-2 virus. Journal of Clinical Virology. 2020;129(104500): 1–4.} found that rapid antigen tests detected between 11.1% – 45.7% of RT-qPCR-positive samples from COVID-19 patients. Due to the lower sensitivity of antigen tests, the FDA^{1US Food & Drug Administration. Coronavirus Testing Basics. FDA. 2020 July 16 [Cited 2020 September 25].} and CDC^{1Centers for Disease Control and Prevention. Interim Guidance for Rapid Antigen Testing for SARS-CoV-2. 2020 Sept 5 [Cited 2020, September 25].} recommend confirming negative results with a RT-qPCR test.

• What are the benefits of saliva over swabs for surveillance testing?

  Due to the minimally invasive and painless nature of saliva collection, saliva is more conducive for routine surveillance testing. Saliva is self-collected and eliminates the need to train specialized healthcare personnel on the collection process, making it easy to collect saliva on a regular basis.

  Studies have also found that saliva is as sensitive^{1Leung EC, Chow VC, Lee MK, Lai RW. Deep throat saliva as an alternative diagnostic specimen type for the detection of SARS‐CoV‐2. Journal of Medical Virology. 2020; 1-4.1Ying-Wong SC, Tse H, Siu HK, Kwong TS, Chu MY, Yau FYS et al. Posterior Oropharyngeal Saliva for the Detection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Clinical Infectious Diseases. 2020; 1-8.} if not more sensitive^{1Yokota I, Shane PY, Okada K, Unoki Y, Yang Y, Inao T et al. Mass screening of asymptomatic persons for SARS-CoV-2 using saliva. medRxiv [Preprint]. 2020 [cited 2020 September 25].1Teo AKJ, Choudhury Y, Tan IB, Cher CY, Chew SH, Wan ZY et al. Validation of Saliva and Self-Administered Nasal Swabs for COVID-19 Testing. medRxiv [Preprint]. 2020 [cited 2020 September 25].} than nasopharyngeal swabs in detecting COVID-19. In addition, the complicated sampling procedure of nasopharyngeal swabbing increases the risk of variable and unreliable results^{1Lippi G, Simundic A, Plebani M. Potential preanalytical and analytical vulnerabilities in the laboratory diagnosis of coronavirus disease 2019 (COVID-19). Clinical Chemistry and Laboratory Medicine. 2020;58(7): 1070-1076.}.

• Can this kit be used to test environmental surfaces?

  No, this kit is intended to detect COVID-19 in a human population. However, our Coronavirus Environmental Surface Test Kit does detect SARS-CoV-2 on high-touch environmental surfaces, such as door handles, tables, shopping carts, and other hard surfaces, using the same Open qPCR technology as our surveillance testing solution. The environmental test kit can be employed as a complementary solution alongside the Coronavirus surveillance test kit to expand your testing efforts in cases where obtaining a saliva sample from every individual is not practical.

  Surface swabbing is especially useful in facilities open to the public, such as hotel rooms, airplanes, and gyms. An example of using both solutions is in a restaurant setting, where the Coronavirus surveillance test kit could be used to routinely monitor workplace personnel, while environmental surface testing detects COVID-19 on high-touch surfaces in areas that are frequently exposed to visitors or customers.

• Are the test kits compatible with instruments other than Open qPCR?

  Yes, the test kits will work with any Real-Time PCR instrument compatible with the FAM and HEX fluorophores.

• Do you ship internationally?

  Yes. We have distributors in most major regions. If we do not have a specific distributor in your country, we will ship and service the kits and instruments directly. Contact us at sales@chaibio.com to help you find the best way to purchase kits and instruments.

• How was the COVID-19 Surveillance Test Kit validated?

  The test kit was validated for its sensitivity, specificity, endogenous interference and cross-reactivity, and clinical performance as detailed in the Validation Report.