A research team at the University of Birmingham has validated the speed, precision, sensitivity and simplicity of a new test to detect Covid-19 in a three-way comparison study. The test, referred to as reverse transcription-free Exponential Amplification Reaction (RTF-EXPAR), was observed to have similar sensitivity and more speed compared to polymerase chain reaction (PCR) and real-time loop-mediated amplification (LAMP) tests presently used in hospitals. The new test offers a sample-to-signal time of less than ten minutes, including for low viral levels where existing lateral flow tests are reported to be less effective.
A new study by researchers at Tulane University in New Orleans, Louisiana has found that monitoring viral load information among Covid-19 positive individuals is not a reliable indicator of disease transmission risk. The study assessed the reliability of cycle thresholds (Ct) from PCR tests as an indicator of the quantity of virus carried by an infected person. A study published in the Journal of Molecular Diagnostics shows that people with even low viral loads can transmit the virus. Testing and contact tracing in the latest study revealed that Ct value alone could not forecast transmissibility and all contacts of positive patients, including those with low virus levels, must be quarantined.
SpeeDx has launched a new product line of research reagents for Covid-19 variant analysis to add a mutation associated with the SARS-CoV-2 Delta variant of concern (VOC). The new PlexPrime SARS-CoV-2 Genotyping product line uses the company’s universal substrate method and multiplexing technology to detect vital VOCs in positive samples. Part of the new portfolio is PlexPrime SARS-CoV-2 P681R Delta, which is a single well mix to identify the SARS-CoV-2 virus’ P681R spike mutation present in B.1.617.2 (Delta) VOC, as well as an RdRp gene target of the virus.