Addresses major testing need in developing world; also in US, where reagent supplies are again dwindling — ScienceDaily


A major roadblock to large scale testing for coronavirus infection in the developing world is a shortage of key chemicals, or reagents, needed for the test, specifically the ones used to extract the virus’s genetic material, or RNA.

A team of scientists at the University of Vermont, working in partnership with a group at the University of Washington, has developed a method of testing for the COVID-19 virus that doesn’t make use of these chemicals but still delivers an accurate result, paving the way for inexpensive, widely available testing in both developing countries and industrialized nations like the United States, where reagent supplies are again in short supply.

The method for the test, published Oct. 2 in PLOS Biology, omits the step in the widely used reverse transcription polymerase chain reaction (RT-PCR) test where the scarce reagents are needed.

92% accuracy, missing only lowest viral loads

The accuracy of the new test was evaluated by a team of researchers at the University of Washington led by Keith Jerome, director of the university’s Molecular Virology Lab, using 215 COVID-19 samples that RT-PCR tests had shown were positive, with a range of viral loads, and 30 that were negative.

It correctly identified 92% of the positive samples and 100% of the negatives.

The positive samples the new test failed to catch had very low levels of the virus. Public health experts increasingly believe that ultra-sensitive tests that identify individuals with even the smallest viral loads are not needed to slow spread of the disease.

“It was a very positive result,” said Jason Botten, an expert on pathogenic RNA viruses at the University of Vermont’s Larner College of Medicine and senior author on the PLOS Biology paper. Botten’s colleague Emily A. Bruce is the paper’s first author.

“You can go for the