Beijing time on March 10, the United States to test new coronary pneumonia, usually nurses with a long cotton swab wipe the back of the patient’s throat, take a sample of pharynx swabs, sent to the laboratory for testing. China and other countries have developed a new coronary pneumonia antibody detection technology. Phaversss samples are suitable for polymerase chain reaction (“PCR”) testing methods, while blood samples are suitable for antibody testing methods.
Amesh Adalja, an infectious disease specialist and senior scholar at the Johns Hopkins Center for Health and Safety, said both tests take hours, meaning tests can come out in a day. He said the rapid detection method was developed, less than an hour can produce results, “at present, other countries and regions have a rapid PCR detection method, but the United States has not.”
The CDC, as well as tests developed in Washington state and New York, are PCR tests.
PCR detection method detects genetic material unique to the new coronary pneumonia virus. Depending on the type of PCR test method, the nurse may take a pharynx, swab sample, or saliva sample.
When the samples are sent to the lab, the researchers extract nucleic acids — genes that contain viruses. Using a technique called reverse transcription polymerase chain reaction, the researchers amplified certain pieces of genetic material – equivalent to obtaining larger samples to compare the genetic material of the neo-coronary pneumonia virus.
The new coronary pneumonia has nearly 30,000 nucleotides — the basic elements of DNA and RNA. Dr. Alex Greninger, assistant professor of laboratory in forensic medicine at the University of Washington and assistant director of the Clinical Virology Laboratory, told the Seattle Times that the PCR test developed by the University of Washington School of Medicine only tests 100 nucleic acids specific to the neo-coronary pneumonia virus.
These 100 nucleotides contain two genes in the genome of the neo-coronary pneumonia virus. If both genes are found in the sample, the test results are positive; if only one gene is found, the test results are uncertain; and if none of the genes are found, the test results are negative.
If the results of the Test at the Washington University School of Medicine are positive or uncertain, the samples will be sent to the Washington State Public Health Laboratory and the CDC for further testing, the Seattle Times reported.
In contrast, serological examinations look for antibodies in the blood – antibodies produced by the body to fight new coronary pneumonia. “If there is a new coronary pneumonia virus antibody in the sample, you can judge the result to be positive, ” Adaja said. Singapore has developed experimental antibody detection technology for the new coronapneumonia virus, and China has approved several new coronapneumonia virus antibody detection products, according to science.
Serological testing has the advantage because it can detect antibodies in the blood even if the patient has recovered; However, if the viral load is low or the body has not yet produced antibodies, both methods may have false negative seqs, Adaja said.
Adja said it would take about a week for the body to produce large numbers of antibodies.
The “New Coronary Virus Pneumonia Treatment Program (Trial 7th Edition)” issued by the National Health and Reform Commission on March 4th added a diagnostic criterion: positive for serum new coronavirus-specific IgM and IgG antibodies; This marks the official inclusion of antibody testing in the diagnostic criteria for new coronary pneumonia. Previously, China mainly through the PCR detection method to detect the new coronary pneumonia virus.