Uncategorized
WHO information notice for IVD users
Product type: Nucleic Acid (NAT) Testing Technologies Using Real-Time Polymerase Chain Reaction (RT-PCR) to Detect SARS-CoV-2
Date: December 7, 2020
WHO identifier: 2020/5, version 1
The purpose of this notice: To ensure that users of certain nucleic acid (NAT) testing technologies are aware of certain aspects of the instructions for use (IFU) for all products.
Problem description: WHO has received user feedback on the increased risk of false SARS-CoV-2 results when testing samples using RT-PCR reagents on open systems.
As with any diagnostic procedure, positive and negative predictive values for a product in a particular test population are important. As the positivity rate for SARS-CoV-2 decreases, the positive predictive value also decreases. This means that the likelihood that a person with a positive result (SARS-CoV-2 detected) is indeed infected with SARS-CoV-2 is reduced by decreasing the positivity rate, regardless of the specificity of the study. Therefore, healthcare providers are encouraged to take into account test results along with clinical signs and symptoms, confirmed status of any contacts, etc.
Users of RT-PCR reagents should read the IFU carefully to determine if manual adjustment of the PCR positivity threshold is required to account for background noise that may lead to a high cycle threshold (Ct) sample being interpreted as a positive result . The design principle of RT-PCR means that patients with high levels of circulating virus (viral load) will require relatively few cycles to detect the virus, so the Ct value will be low. Conversely, when samples return a high Ct value, it means that many cycles were required to detect the virus. In some circumstances, it is difficult to distinguish between background noise and the actual presence of the target virus. Therefore, the IFU will specify how to interpret samples at or near the limit for PCR positivity. In some cases, the IFU will state that the cut-off value should be manually adjusted to ensure that samples with high Ct values are not incorrectly assigned SARS-CoV-2 due to background noise.
Manufacturers regularly review the design of their product, including labeling and IFUs based on customer feedback. In the early stages of the COVID-19 pandemic, in vitro diagnostics (IVD) was rapidly developed, validated and verified, and then introduced. It is therefore not unexpected that IVDs may require refinement based on user feedback after their introduction into the scope. Users should check the version of the IFU with each shipment they receive to see if any changes have been made to the IFU.
Tips on actions to be taken by users:
- Please read the IFU carefully in its entirety.
- If there is any aspect of the IFU that is unclear to you, contact your local representative.
- Check the IFU for each incoming shipment to detect any changes in the IFU.
- Consider any positive result (SARS-CoV-2 detected) or negative result (SARS-CoV-2 not detected) in combination with sample type, clinical observations, patient history, and epidemiological information.
- Give the Ct value in the report to the healthcare provider.
Transmission of this WHO Information Notice to Users:
Send this notice to anyone who needs to be familiar with your organization or any organization in which a potentially affected product is installed and used.
Contact person for further information:
Anita SANDS, Regulation and Prequalification, World Health Organization, e-mail: [email protected]
What Are The Main Benefits Of Comparing Car Insurance Quotes Online
LOS ANGELES, CA / ACCESSWIRE / June 24, 2020, / Compare-autoinsurance.Org has launched a new blog post that presents the main benefits of comparing multiple car insurance quotes. For more info and free online quotes, please visit https://compare-autoinsurance.Org/the-advantages-of-comparing-prices-with-car-insurance-quotes-online/ The modern society has numerous technological advantages. One important advantage is the speed at which information is sent and received. With the help of the internet, the shopping habits of many persons have drastically changed. The car insurance industry hasn't remained untouched by these changes. On the internet, drivers can compare insurance prices and find out which sellers have the best offers. View photos The advantages of comparing online car insurance quotes are the following: Online quotes can be obtained from anywhere and at any time. Unlike physical insurance agencies, websites don't have a specific schedule and they are available at any time. Drivers that have busy working schedules, can compare quotes from anywhere and at any time, even at midnight. Multiple choices. Almost all insurance providers, no matter if they are well-known brands or just local insurers, have an online presence. Online quotes will allow policyholders the chance to discover multiple insurance companies and check their prices. Drivers are no longer required to get quotes from just a few known insurance companies. Also, local and regional insurers can provide lower insurance rates for the same services. Accurate insurance estimates. Online quotes can only be accurate if the customers provide accurate and real info about their car models and driving history. Lying about past driving incidents can make the price estimates to be lower, but when dealing with an insurance company lying to them is useless. Usually, insurance companies will do research about a potential customer before granting him coverage. Online quotes can be sorted easily. Although drivers are recommended to not choose a policy just based on its price, drivers can easily sort quotes by insurance price. Using brokerage websites will allow drivers to get quotes from multiple insurers, thus making the comparison faster and easier. For additional info, money-saving tips, and free car insurance quotes, visit https://compare-autoinsurance.Org/ Compare-autoinsurance.Org is an online provider of life, home, health, and auto insurance quotes. This website is unique because it does not simply stick to one kind of insurance provider, but brings the clients the best deals from many different online insurance carriers. In this way, clients have access to offers from multiple carriers all in one place: this website. On this site, customers have access to quotes for insurance plans from various agencies, such as local or nationwide agencies, brand names insurance companies, etc. "Online quotes can easily help drivers obtain better car insurance deals. All they have to do is to complete an online form with accurate and real info, then compare prices", said Russell Rabichev, Marketing Director of Internet Marketing Company. CONTACT: Company Name: Internet Marketing CompanyPerson for contact Name: Gurgu CPhone Number: (818) 359-3898Email: [email protected]: https://compare-autoinsurance.Org/ SOURCE: Compare-autoinsurance.Org View source version on accesswire.Com:https://www.Accesswire.Com/595055/What-Are-The-Main-Benefits-Of-Comparing-Car-Insurance-Quotes-Online View photos
Thanks WHO For Help!
 |
 |
 |