Genetic testing of saliva samples identifies COVID-19: study

During the outbreak of the COVID-19 pandemic, the urgent need to increase testing was caused by a lack of materials, especially nasal swabs, which are standard methods for collecting test samples. Therefore, genetic testing was used to overcome these.

To identify people infected with COVID-19, researchers began weekly testing of saliva samples from volunteers in healthy areas in May 2020 and continued for the next two years. Among asymptomatic volunteers who tested positive, Milton and his colleagues found that the patient usually showed symptoms one or two days later.

However, genetic testing gave slightly faster results. “”It wondered if saliva was better at catching presymptomatic patients than traditional nasal swabs.” He said.

The researchers answered the question using data from subsequent studies of people who were in close contact with COVID-19 patients. In this study, “Samples of saliva and middle turbinate (nasal) swabs were collected from contacts every 2-3 days during the quarantine period.“Milton said.”All samples were tested using real-time reverse transcription-polymerase chain reaction (RT-PCR) to detect SARS-CoV-2 and measure the amount of viral RNA contained in the samples. Next, we analyzed how these results changed the days before and after the onset of symptoms.“”

“”In the early stages of infection, saliva was significantly more sensitive than the nasal swab of the middle turbinate.“Especially before the onset of symptoms,” studies show, previous studies have shown that presymptomatic infections play a greater role than symptomatic infections with COVID-19.

These findings will impact improving public acceptance of COVID-19 testing, reducing the cost of high-volume COVID-19 screening, and improving the safety of healthcare professionals performing the test. In the second case, a self-test of saliva samples prevents the patient from close contact with the medical professional during a nasal swab and prevents the patient from coughing or sneezing. This spreads viral particles from sensitive nasal passages and due to patient discomfort. Therefore, genetic testing is an easy and effective method.

“”Our research supports the use of saliva in large-scale screening in schools and workplaces, improves screening rates, and enables early detection.“Milton said.”The availability of rapid saliva testing is expected to be a major advance from current nasal swab-based rapid testing.“”

Source: Medindia

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