Covid-19 virus test results may vary depending on time of day: Study

Research published Tuesday in the Journal of Biological Rhythms found that people were up to two times more likely to have an accurate positive test result if they took the test in the middle of the day than at night.

The researchers said the finding supports the hypothesis that COVID-19 acts differently in the body based on our natural circadian rhythm, which has also been implied by studies of other viral and bacterial infections, The researchers said.

The circadian rhythm is our body’s natural, internal process that regulates the sleep-wake cycle and repeats approximately every 24 hours.

Researchers said that when infected cells release virus particles into the blood and mucus, it appears to be more active in the middle of the day due to the modulation of the immune system by our biological clock.

Professor Carl Johnson from Vanderbilt University in the US said, “Taking a COVID-19 test at the optimum time of day improves test sensitivity and will help us diagnose people who may be infected but may be asymptomatic. Huh.”

According to the researchers, the results showed that the viral load decreased after 8 pm.

If people choose to get tested at that time, there could be a higher chance of a false-negative result, he said.

The difference in COVID-19 viral shedding across the day is important information that could reveal how we test and treat the virus, the researchers said.

That peak in the afternoon, when patients are more likely to interact with others or seek medical care, may play a role in increasing the spread of the virus in hospitals and the wider community, he said.

The researchers noted that further research is needed to confirm the nature of SARS-CoV-2 — active during the day — being active during the day.

Johnson said experimentally testing patients who are infected with COVID-19 to see if individuals shed the virus differently throughout the day would have a significant impact on public health.

He said the research could be used to optimize COVID-19 testing and improve test accuracy.

Researchers believe that tentative considerations can be leveraged to maximize the effectiveness of intervention strategies and even vaccine strategies.