Covid Patients Release More Viral Particles During Talking, Singing

Surprisingly, some patients surprisingly released more virus from talking than singing. Read on to know how you can reduce exposure to fine aerosols in indoor environments .

The novel coronavirus that causes COVID-19 spreads primarily when an infected person coughs or sneezes. This is what it was researchers and medical experts have though until now. But a new study by the National University of Singapore (NUS) has revealed that fine aerosols emitted by an infected person during talking and singing may play a crucial role in COVID-19 transmission, especially in an indoor environment.

Surprisingly, the NUS researchers found that fine aerosols (less than 5 micrometres) generated from these two types of activities (talking and singing) contain more viral particles than coarse aerosols (more than 5 micrometres). Based on these findings, the research team highlighted the importance of reducing exposure to fine respiratory aerosols, especially in indoor environments.

"To our knowledge, this is the first study to quantify and compare SARS-CoV-2 particles in aerosols generated through breathing, talking and singing. Therefore, our team's work provides a foundation for estimating the risk of transmission of infection," said project leader Associate Professor Tham Kwok Wai from the Department of the Built Environment at the NUS School of Design and Environment, as quoted by Science Daily.

The study was first published online in the journal Clinical Infectious Diseases on 6 August 2021.

Some patients release more virus from talking than singing

For the study, the research team recruited 22 COVID-19 positive patients who were admitted to the National Centre for Infectious Diseases (NCID) from February to April 2021.

The participants were asked to perform three separate expiratory activities using a specially designed exhalation collection equipment known as the Gesundheit-II. These activities included 30 minutes of breathing, 15 minutes of talking in the form of reading aloud passages from a children's book, and 15 minutes of singing different songs. Aerosols were collected in two size fractions, namely coarse and fine. The sample viral load was quantified by using the reverse transcription-quantitative polymerase chain reaction method.

They found that patients who are early in the course of illness are more likely to shed detectable levels of SARS-CoV-2 RNA in respiratory aerosols. "Some patients surprisingly released more virus from talking than singing," stated project co-leader Dr Kristen Coleman from Duke-NUS Medical School.

How to reduce exposure to fine aerosols

The study underscored that exposure to fine-particle aerosols needs to be mitigated, especially in indoor environments where airborne transmission of SARS-CoV-2 is most likely to occur. According to the researchers, exposure to fine respiratory aerosols can be reduced through non-pharmaceutical interventions, such as:

• Universal masking
• Physical distancing
• Increased room ventilation
• More efficient filtration and
• Appropriately applied air-cleaning technologies.

In situations involving singing, they suggested safe distancing among singers, as well as the averting and filtering of airflow from choir to audience, such as by deploying air curtains, are important considerations. For situations involving talking, practical options that can be taken to lower the risk of SARS-CoV-2 transmission include seating and furniture configurations, distancing, and air movement alteration, such as fans.

Basically, the researchers recommended a multi-layered approach of control measures to decrease the risk of airborne SARS-CoV-2 transmission.