COVID-19 Transmission Risks from Singing and Playing Wind Instruments

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SYNOPSIS 11/18/2020 COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far

Introduction Public Health Ontario (PHO) is actively monitoring, reviewing and assessing relevant information related to Coronavirus Disease 2019 (COVID-19). “What We Know So Far” documents provide a rapid review of the evidence related to a specific aspect or emerging issue related to COVID-19. Updates to our Latest Version In the latest version of COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far, we present results of an updated literature search and rapid review.

The updated version provides additional evidence concerning potential COVID-19 transmission during singing and playing wind instruments, including the addition of 22 new articles. We identified 10 new studies on experimental transmission during singing or playing wind instruments; four additional articles reported observational studies on transmission during singing; and there were two reviews of transmission risks during performances. We identified six articles on transmission risks during performances from the grey literature. There have been no published reports on COVID-19 transmission from wind instruments.

The findings from this updated rapid review do not change our previous assessment of COVID-19 transmission during singing and playing wind instruments. Key Findings  Singing generates respiratory droplets and aerosols; however, the degree to which each of these particles contributes to COVID-19 transmission is unclear. The evidence supporting COVID-19 transmission during singing is limited to a small number of observational studies and experimental models. Thirteen of 1,548 (<1%) documented superspreading events have been associated with singing.  Playing wind instruments can produce respiratory droplets and aerosols and, in non-COVID-19- pathogen studies, instruments potentially contribute to fomite transmission. There have been no published reports that playing wind instruments has contributed to COVID-19 transmission.  Performance organizers can mitigate COVID-19 transmission by ensuring musicians and audience members socially distance themselves, wear masks (if possible), wash their hands, and avoid sharing equipment or materials. The use of larger venues to reduce crowding, outdoor

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 1 settings, routine cleaning of surfaces, shortened performances and optimized ventilation may mitigate risks associated with musical performances. Background Available epidemiological evidence suggests the primary route of COVID-19 transmission is through respiratory droplets during prolonged and unprotected close contact.1 Current evidence supports non- airborne transmission as the most common route; however, under favourable conditions transmission through aerosols can occur. In addition, there is the potential for fomite (via contaminated surfaces) transmission.

Early in the pandemic, there were reports of COVID-19 transmission among choir members, prompting queries into the role of singing in virus transmission.2,3 In addition, there were concerns raised about the potential for COVID-19 transmission from playing of wind instruments.

The purpose of this rapid review is to examine the potential for COVID-19 transmission from singing and playing wind instruments. Methods In considering feasibility, scope, and the need for responsiveness, we chose a rapid review as an appropriate approach to determining the occurrence of COVID-19 transmission from singing and the playing wind instruments. A rapid review is a type of knowledge synthesis wherein certain steps of the systematic review process are compromised in order to be timely (e.g., quality assessment).4

On October 26, 2020, PHO Library Services conducted a primary literature search in MEDLINE and Embase (Appendix A; the search for the July 7, 2020, version was performed on June 27, 2020). In addition, we performed a search of the grey literature on October 30, 2020 (Appendix B). We searched PubMed and Google Scholar on October 29, 2020 for additional articles of interest.

English-language peer-reviewed and grey literature records that described respiratory droplet and aerosol production and pathogen transmission during singing or playing wind instruments were included. We did not restrict the search by year of publication. We reviewed citations from included studies to identify additional research.

Prior to posting, PHO subject-matter experts review all “What We Know So Far” documents. As the COVID-19 outbreak continues to evolve and the scientific evidence rapidly expands, the information provided in these documents is only current as of the date of latest literature search. COVID-19 Transmission during Singing and Playing Wind Instruments Relevant studies on this topic are generally in two groups:

1. Studies reporting on the generation of respiratory droplets and aerosols during singing or playing a wind instrument

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 2 2. Studies reporting transmission of COVID-19 and non-COVID-19 pathogens during singing or playing a wind instrument

Neither type of evidence was conclusive with regard to COVID-19 transmission during singing or playing wind instruments. Though the magnitude remains unclear, there was some evidence suggesting that transmission occurred during singing. There were no studies demonstrating the transmission of COVID- 19 from playing wind instruments. Transmission during Singing The reviewed literature demonstrated that singing generated respiratory droplets and aerosols; however, the degree to which each of these particle types contributed to COVID-19 transmission was unclear. The evidence supporting COVID-19 transmission during singing was limited to a few observational studies and experimental models.

EVIDENCE FOR THE PRODUCTION OF RESPIRATORY DROPLETS AND AEROSOLS DURING SINGING Current evidence suggests that the primary mode of transmission of COVID-19 is through respiratory droplets during prolonged and unprotected close contact (virus invades through mucous membranes of the mouth, nose and eyes).1 However, we note that transmission occurs on a spectrum from larger respiratory droplets that spread at close range to smaller aerosols that can become suspended in the air and potentially infectious over longer distances.

Aerosol scientists define a droplet as a particle with a diameter greater than 100 µm, while an aerosol particle has a diameter less than 100 µm.5 Infectious disease experts traditionally define these particles differently, where a droplet has a diameter greater than 5 µm and an aerosol particle has a diameter less than 5 µm. For simplicity in this document, we will use the diameter of 100 µm to distinguish droplets and aerosols (unless otherwise indicated). Overall, most of the particles released by human vocalizations have a diameter less than 10 µm.

Experimental studies demonstrated production of respiratory droplets and aerosols during singing. In addition to particle size, the distance travelled by particles was dependent upon aspects of ventilation and vocalization type.

Distance travelled by respiratory droplets and aerosols

Most studies reported that the distance travelled by respiratory droplets and aerosols expelled by vocalizations was less than 2 m (two studies examining singing).6,7 However, other observational and experimental models showed that respiratory particles travel over 2 m under favourable circumstances.

In an experiment where subjects inhaled e-cigarette smoke, Echternach et al. reported that the distance smoke travelled (n=10 subjects each for speaking, singing) ranged from 0.6 m to 1.4 m.6 The average distance smoke travelled was similar after breathing (1.2 m) and coughing (1.3 m).

In a simulation study using the schlieren imaging method, Becher et al. demonstrated that air expelled from baritone and soprano singers (n=1 subject each) travelled approximately 60 cm to 92 cm.7 In a mathematical modelling study by Netz and Eaton, droplets with a diameter greater than 42 µm (at a relative humidity of 50% and a height of 1.5 m) fell to the ground before drying out, while droplets with

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 3 a diameter less than 42 µm floated in the air in a dried state.8 The authors note the potential for virions in droplets to remain suspended in air.

A systematic review by Bahl et al. reported the horizontal distance travelled by respiratory droplets during sneezing and/or coughing was usually less than 2 m, but in some cases, the distance traveled was up to 8 m.9 In the Bahl et al. review, the size of droplets ranged in diameter from less than 10 µm to 96 µm. In an experimental and statistical simulation of speech (n=1 subject), Abkarian et al. reported that particles emitted from the mouth during talking reached a distance of just over 2 m in 30 seconds, but lost approximately 97% of their initial volume at this distance.10 In hospital wards, Guo et al. reported the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in air samples up to 4 m away from patients (n=2) with COVID-19; however, the authors did not determine the viability of virus in air samples.11

Respiratory droplet and aerosol emission - quantity, rate and size

In the studies reviewed, most particles emitted during breathing, speaking, coughing and singing had a diameter less than 10 µm. Particle quantity and emission rate increased with volume of vocalization and was higher in singing compared to breathing and speaking. In all studies, particle quantity and emission rate varied widely between individuals.

In a study by Alsved et al., the number of respiratory aerosols (diameter 0.5–10 µm) emitted per second varied by vocalization activity (n=12 singers).12 The highest median rate of aerosol emission was from loud singing with exaggerated diction (1,480 particles/s [range: 500–2,820]), followed by loud singing (980 particles/s [390–2,870]), normal singing (690 particles/s [320–2,870]), loud talking (570 particles/s [180–1,760]), normal talking (270 particles/s [120–1,380]) and breathing (135 particles/s [85–691]). Wearing masks during loud singing produced a median emission rate of 410 particles/s (200–1,150), which was not significantly different from median emission rate for normal talking without a mask of 570 particle/s (180–1,760) (p=0.08). In addition, Alsved et al. sampled air at 0.8 m in front of two patients with COVID-19 (within two days of symptom-onset with unknown viral loads) during breathing, speaking and singing with or without a mask for 10 minutes each, but the authors did not detect viral RNA in air samples.

Mürbe et al., in a study of eight professional singers (five replications each), showed greater than 99% of emitted respiratory particles had a diameter of 5 µm or less.13 Singing produced more particles (753.4– 6,093.1 particles/s) than breathing (4.7–428.6 particles/s) or speaking (14.1–390.8 particles/s).

In studies that examined breathing and speaking, generalizability of findings to singing was unclear. Anfinrud et al. noted that during speaking (n=1 subject), more respiratory particles may be generated as speaking becomes louder.14 Asadi et al. demonstrated that the rate of particle emission (mean diameter size was 1 µm) increased as speaking became louder (n=10 subjects); however, they noted that the rate was highly variable between individuals.15 Kwon et al. described how air expelled through coughing had an initial velocity of 15.3 m/s in males (n=17) and 10.6 m/s in females (n=9), compared to speaking which was 4.1 m/s in females and 2.3 m/s in males.16 In a study visualizing particle emission rates during different vocalizations (number of subjects and replications were not reported), Bahl et al. reported that the maximum velocity during singing was 6 m/s (similar to speaking), but 90% of particles travelled at less than 1 m/s at 15 cm from the mouth.17

In 1968, Loudon and Roberts demonstrated that singing produced fewer respiratory droplets (4,014), compared to talking (10,587) and coughing (41,857) (n=3 subjects for each vocalization).18 However, the percentage of respiratory droplets that remained as aerosols (diameter less than 100 µm) after 30

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 4 minutes was highest for coughing (48.9%), followed by singing (35.7%) and talking (6.4%). Readers must interpret the results of this experiment with caution, as the sample size was limited to three individuals, and the technology used for measurements at the time is not the same as used today. EVIDENCE FOR THE TRANSMISSION OF COVID-19 DURING SINGING Several studies described COVID-19 transmission during singing; however, it is challenging to differentiate routes of transmission from these studies.

In a database of 1,548 COVID-19 superspreading events from peer-reviewed and grey literature, Swinkels reported that 0.84% (n=13) of events were associated with indoor singing (i.e., choir, choir recital, choir practice, concert); cases from singing events represented 0.38% (735/195,776) of all cases from superspreading events (as of October 28, 2020).19

For an overview of additional examples of COVID-19 transmission during singing (e.g., choirs, karaoke, concerts, band rehearsals, theatre performances), see the review by O’Keeffe (National Collaborating Centre for Environmental Health).20 In an outbreak in Québec City, Québec, two index cases attended a karaoke bar, leading to over 80 secondary cases.

In a recent scoping review, Weed and Foad assessed approximately 25,000 patients with COVID-19 and found few examples of outdoor exposure and transmission, concluding that the risk of outdoor transmission was low compared to indoor settings.21 In the majority of studies in the scoping review, the exposures were during “everyday life” and may not be applicable to outdoor performances by choirs and orchestras.

Choirs

Several studies reviewed for this rapid review concluded that the act of singing in a choir contributed, in part, to COVID-19 transmission events with high secondary attack rates (studies described below). In several studies, the authors attributed spread to aerosol transmission; however, there was a possibility of transmission from respiratory droplets during prolonged and unprotected close contact or from contact with shared surfaces (fomites). It was also uncertain if the size of the indoor space and/or the quality of ventilation may have played a role in these transmission events.

In Skagit County, Washington in the United States (US), Hamner et al. reported on an outbreak of COVID-19 among members of a church choir.3 Transmission occurred during a 2.5 h choir practice, in which there were 61 attendees. A symptomatic case led to 32 confirmed and 20 probable secondary cases, resulting in secondary attack rates ranging from 53.3% (confirmed cases only) to 86.7% (confirmed and probable cases). The authors concluded that a number of factors contributed to transmission, including close proximity (15–25 cm for part of the time) for prolonged periods (2.5 h) indoors, touching shared surfaces (e.g., stacking chairs, sharing snacks), and possibly facilitated by the act of singing and release of aerosols.

In France, Charlotte reported that a COVID-19 outbreak occurred during a 25-person choir practice in a small, non-ventilated room.22 The secondary attack rate was 70% and the author concluded that singing might aide transmission through the production of respiratory droplets and aerosols.

Studies show that effective ventilation reduces pathogen transmission in rehearsal and performance settings. Hartmann et al. proposed that breaks (leaving space for 15 min) during singing performances in rehearsal rooms and concert halls could reduce aerosol accumulation, and that ventilation is potentially more effective in this goal than opening windows (passive ventilation).23 In a modelling study, Lelieveld

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 5 et al. demonstrated that in a non-superspreading event during choir practice, individual risk of infection was reduced from 29% (passive ventilation, no mask use) to 12% (active air ventilation, no mask use) to 3.3% (high-volume filtration with HEPA, no mask use).24

Other settings (e.g., churches, karaoke, parties, concerts)

Numerous cluster and outbreak investigations reported that singing possibly contributed to COVID-19. In the majority of these studies, transmission was likely through respiratory droplets and aerosols during prolonged and unprotected close contact and through fomite transmission during touching of common surfaces.

In Singapore, Wei et al. described seven clusters of COVID-19 cases and presumed there was presymptomatic transmission.25 In two of these clusters, a presymptomatic case infected another person during a singing class. In South Africa, Jaja et al. suggested that COVID-19 outbreaks were often associated with funeral and church services where singing occurred and social distancing guidelines were not routinely adhered to.26 The authors stated “During church services, congregant[s] sing and worship loudly, sit close to each other and often touch surface/fomite which may be contaminated.” In Japan, Furuse et al. identified 61 clusters of COVID-19 (a cluster defined as five or more cases), of which seven (11.5%) were events involving singing and music (e.g., concerts, choir rehearsals, karaoke parties).27 The authors note that many of these clusters involved heavy breathing where people were in close proximity. Also in Japan, prior to a ban on mass gatherings and rules on social distancing, Koizumi et al. reported that a single infectious concertgoer led to 103 secondary and tertiary cases across eight live concert venues (50–100 capacity).28 In Hong Kong, Cheng et al. reported that 11 clusters involving 113 cases were associated with people not wearing masks in several settings, including “singing at karaoke.”29 Two other epidemiologic studies identified clusters of COVID-19 cases that occurred in the context of church service attendance; however, the authors did not address the role that singing played in transmission.30,31 In the US state of Georgia, Szablewski et al. reported on an outbreak of COVID-19 in a camp, where the authors contend indoor and outdoor cheering and singing potentially contributed to transmission.32

In a study of a superspreading event during a carnival in Gangelt, Germany, Streeck et al. noted that “loud talking and singing in close proximity” were common behaviours at the carnival.33 Among the COVID-19 cases identified in the study (15.5% of those tested with complete epidemiological information; N=919), individuals who attended the carnival had a significantly higher infection rate (21.3%) compared to people who did not attend the carnival (9.5%) (p<0.001). The authors concluded that loud voices and singing in close proximity may have released more virus in the air and led to more severe infections. EVIDENCE FOR THE TRANSMISSION OF NON-COVID-19 PATHOGENS DURING SINGING There were several examples in the literature where non-COVID-19 pathogen transmission occurred during singing, such as in a choir. Readers must use caution when assessing the generalizability of these examples to COVID-19, as the epidemiology and transmission of these pathogens may be different (e.g., tuberculosis [TB] is primarily an airborne infection).

The most commonly reported pathogen transmitted during singing is Mycobacterium tuberculosis (causative agent of TB), and studies of TB transmission in this context date back to at least 1968.18 Since then, researchers have documented several outbreaks among school and church choir members.34-36 In

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 6 addition, the authors considered various factors aside from singing as potentially contributing to transmission (e.g., lack of ventilation, prolonged close contact, exposure outside of choir activities).

Kar-Purkaystha et al. reported on an cluster of influenza A (H1N1) infections in 2009 in the United Kingdom (UK) involving 3 schools, a party and a choir.37 In this study, the secondary attack rate for the choir setting was 4.2% (7/168), compared to rates between 1.0% (1/96) and 25.0% (2/8) for a single class and a party, respectively.

In another UK study, Briscoe et al. reported an outbreak of streptococcal throat infections (group A Streptococcus) among students at a boys’ school, including some choir members.38 During three school terms, 38.9% (37/95) of boys, including 46.4% (13/28) of choir members, tested positive. The authors attested the infection likely spread among classes, dormitories and the choir; there was no evidence that choir members were at higher risk of infection than non-choir members. Transmission from Playing Wind Instruments There were no studies in the literature that reported that playing wind instruments contributed to COVID-19 transmission. Studies demonstrated that playing wind instruments produced respiratory droplets/aerosols and, in non-COVID-19-pathogen studies, instruments potentially contributed to fomite transmission. Currently, the degree to which playing wind instruments contributes to COVID-19 transmission is unclear.

EVIDENCE FOR THE PRODUCTION OF INFECTIOUS RESPIRATORY DROPLETS AND AEROSOLS WHILE PLAYING WIND INSTRUMENTS Distance travelled by respiratory droplets and aerosols

All the studies examined for this rapid review showed that particles emitted from wind instruments travelled less than 2 m, but readers should note the basis for this conclusion was three non-peer- reviewed studies.

The Vienna Philharmonic conducted experiments measuring airflow and air movement while playing wind instruments.39 The goal of this exercise was to document airflow from wind instruments and the musicians while playing, using photography. The article does not provide sufficient details for replication. In brief, the authors provided a steady flow of aerosolized salt solution via nasal prongs to musicians’ nostrils to create photographable, measurable clouds of their exhalations as they played. While this study mentions “aerosols”, the authors did not measure droplet size and did not report the sensitivity of the photographic method used to visualize the aerosols. Normal breathing showed a cloud of fog emitted approximately 50 cm away from the nose and mouth. For string instruments, this observation remained unchanged while playing (versus while at rest). For winds, “aerosols” were not reported or were “hardly visible” from the opening at the end of the wind instrument, with the exception of the flute, for which a larger amount of “aerosol” escaped from the opening at the end of the instrument, leading to a cloud formation in the maximum range of approximately 75 cm. The authors expected that a musician’s exhaled air does not expand by more than approximately 80 cm, and is therefore within the 2 m distance recommended for physical distancing.

Spahn et al. conducted a risk assessment in the field of music, based in part on data from a study of wind instrument players and singers with the Bamberg Symphony Orchestra.40 In this study, authors measured air movement using a sensor placed near the musician during the performance. The authors

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 7 concluded that a minimum of 2 m distance between musicians (including winds) was sufficient, as there was no detection of additional movement of indoor air during playing at this distance. Therefore, the risk of droplet transmission, if participants follow this distance protocol, was low. Similarly, the authors provided similar recommendations for singing (e.g., 2 m apart is sufficient based on results from their experiment). Of note, the authors proposed a number of preventive measures to mitigate the potential risk of COVID-19 transmission during musical activities, including reducing the duration of the activity to allow for regular airing out of the space and applying cloth protection to the bells of wind instruments where feasible. Similar to the Vienna Philharmonic study, this work does not address aerosol production by wind instruments or musicians.

In a simulation study using the schlieren imaging method, Becher et al. reported that air expelled by different wind and brass instruments (11 instruments, n=1 each) and exhaled by musicians travelled from less than 25 cm while playing the traverse flute, to about 60 cm in playing the double horn, to about 80 cm in baritone singers.7 The authors did not measure the particle sizes.

Respiratory droplet and aerosol emission - quantity, concentration, rate and size

Researchers that studied particle emission from musical instruments employed a wide variety of methodologies using different units of measure, creating a high degree of variability in results and making results difficult to compare. In general, the concentration and quantity of particles was higher when playing trumpets, trombones or oboes, and lower when playing tubas, flutes or clarinets.

In an experiment, He et al. reported a large variation in aerosol concentrations produced by 10 different brass and woodwind instruments with an average diameter, depending on instrument, of 1.9–3.1 µm (n=2 with 5 replications each for bassoon, clarinet, flute, French horn, oboe and trumpet; n=1 with five replications each for bass clarinet, piccolo and tuba).41 Aerosol concentrations were lower for breathing (mean ± standard error [SE] aerosol concentration: ≈ 90 ± 65 particles/L; n=15 subjects with 20 replications each), compared to speaking (≈ 230 ± 95 particles/L; n=15 subjects with 5 replications each). Compared to breathing, aerosol concentrations were lower playing the tuba (low risk). Playing the bassoon, piccolo, flute, bass clarinet, French horn and clarinet produced aerosol concentrations similar to breathing and speaking (intermediate risk). Playing the trumpet, oboe and bass trombone produced aerosol concentrations higher than speaking (high risk).

In an experiment of seven different brass instruments (n=1 subject, each with 5 replications), Parker and Crookston measured emission of droplet (diameter greater than 5 µm) and aerosol (diameter less than 5 µm) particles.42 The mean ± SE concentration of droplets for all instruments was 1.4×104 ± 9.0×102 particles/m3 and for aerosols was 1.2×107 ± 1.0×106 particles/m3 per minute (highest for trombone and lowest for tuba). Droplet concentrations were higher from instruments compared to breathing, but aerosol concentrations were similar from instruments (with barrier cap) and breathing. For breathing, the concentration of droplets was 5.5×103 ± 1.2×103 particle/m3 and for aerosols was 1.6×107 ± 1.3×106 particles/m3. Using a barrier cap on the bell of the instrument reduced the concentration of droplet emissions by 63.8% and aerosol emissions by 78.5%.

In an unpublished study of aerosol emissions from various wind instruments (n=1–5 per instrument), Volckens et al. reported that emission of aerosols (less than or equal to 100 µm) varied in terms of aerosol concentration and size.43 Based on preliminary results, instruments with higher levels of emissions were the trumpet, saxophone and bassoon, followed by intermediate levels (French horn, oboe), and low levels (flute, piccolo).

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 8 Lai et al. compared the quantity and size of aerosols emitted while playing vuvuzelas (plastic horns used by sports fans) and shouting.44 The mean concentration of aerosols from playing the vuvuzela and shouting (n=8 each) were 658,000 particles/L and 3,700 particles/L, respectively. The mean peak flow rate of air exiting the vuvuzela was 6.1 L/s and for shouting was 1.8 L/s. 97% of particles captured from the vuvuzela and shouting had a diameter of 0.5 µm to 5 µm. The authors concluded that playing the vuvuzela had the capacity to propel large numbers of aerosols into the air, potentially acting as a conduit for the spread of infectious particles. The vuvuzela is essentially a straight, long, flared plastic tube with no keys; therefore, there are no equivalent instruments used in most organized musical settings (e.g., typical brass or woodwind band instruments), which all have bends and/or keys, which create turbulence and impede direct airflow (and particle dispersion).45 Therefore, we cannot generalize these findings to other wind instruments.

Brandt studied aerosol particle (diameter less than or equal to 10 µm) emissions from brass and wind instruments (n=1 each for 8 instruments) and coughing (n=1) at varying distances.46 There were no differences in the concentration of particles by distance from the instrument (up to 4 m). The highest particle concentration produced was from the oboe (0.036 mg/m3) and the lowest was from the clarinet (0.007 mg/m3). At a distance of 0.5 m from the instrumentalist, coughing produced a particle concentration of 9,593 mg/m3, which was 70,000 times higher than that produced by playing instruments.

Aside from the direct expulsion of aerosols from wind instruments, Schwalje et al. described the possibility of aerosol generation through deep breathing and forceful exhalation while playing wind instruments.47 Additionally, people learning to play these instruments potentially release more aerosols.

EVIDENCE FOR SURVIVABILITY OF SARS-COV-2 ON WIND INSTRUMENTS There have been no studies performed on the survivability of COVID-19 on wind instruments; however, researchers have performed SARS-CoV-2 survivability studies on metals such as stainless steel and copper. Under experimental conditions, SARS-CoV-2 survives on metals for several days, but it is unclear whether this represents an infectious dose. van Doremalen et al. compared the surface stability of SARS-CoV-2 and SARS-CoV-1.48 The authors noted an exponential decay in virus titre for both viruses in all experimental conditions (n=3 replicates). At 40% relative humidity and room temperature (21–23°C), SARS-CoV-2 and SARS-CoV-1 were detectable for up to 2–3 d on plastic and stainless steel. On copper, there was no detection of live SARS-CoV-2 and SARS- CoV-1 after 4 h and 8 h, respectively. The estimated median half-life for SARS-CoV-2 on copper was 0.8 h and on stainless steel was 5.6 h. While this study concluded that fomite transmission is possible, it did not demonstrate that it occurs under natural conditions.

Riddell et al. tested the stability of SARS-CoV-2 under controlled conditions on multiple surface types (n=3 replicates).49 The authors concluded that infectious virus survived on stainless steel for 28 d at 20°C and 50% relative humidity in the dark (7 d at 30°C). In addition, virus titres decreased by 90% by 10 d post-inoculation at 20°C on all surfaces.

Chin et al. reported on the stability of SARS-CoV-2 under different environmental conditions (n=3 replicates).50 At 22°C and a relative humidity of 65%, the authors did not detect viable virus on stainless steel after 7 d. The authors noted that to recover the virus from the experimental surfaces, inoculated objects were immediately soaked in transport medium after the pre-set exposure time. As a result, the findings do not necessarily reflect the potential to acquire the virus from casual contact.

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 9 EVIDENCE FOR THE TRANSMISSION OF NON-COVID-19 PATHOGENS VIA WIND INSTRUMENTS Several studies have demonstrated contamination of wind instruments by non-COVID-19 pathogens, potentially implicating instruments as fomites.

Denton et al. reported on a patient with cystic fibrosis recurrently infected with Burkholderia cenocepacia IIIB, which is an opportunistic lung pathogen.51 The authors implicated the patient’s trombone as the potential source of the infection based on culturing the same pathogen from his sputum and the instrument (spit valve, but not mouthpiece). A study by Corrao identified Mycobacterium kansasii from a sputum culture of a trombone player and in the trombone slide, which the author argued may represent the source of infection.52 In both cases, the authors did not entertain the possibility that deposition of pathogens on instruments occurred after infection of musicians.

Drover et al. reported on the findings from 52 questionnaires completed by university orchestra members.53 Lung infection rates were higher in musicians compared to the public, which the authors attributed to poor instrument hygiene. Glass et al. noted that bacterial and fungal contamination of wind instruments (n=13) was highest near the mouthpiece (unlike Denton et al., Corrao).51,52,54 Shared instruments are a potential source of infection, especially among students.55

In a study examining bacterial and fungal contamination of wind instruments (n=20), Marshall and Levy demonstrated that instruments played in the previous three days had the most mouth-associated microbial flora.56 In addition, reed instruments, compared to flutes and trumpets, had higher microbial loads. This study did not examine the viability of pathogens on instruments. A similar study by Mobley and Bridges looked specifically at the microbial content of 30 samples of spit valve liquids taken from five types of brass instruments, and found evidence of environmental flora (Alcaligenes faecalis) in most, and 16.7% showed the presence of oral flora (e.g., Streptococcus species).57 Conclusion The evidence for COVID-19 transmission from singing or playing wind instruments is mostly from experimental studies that demonstrate the potential for respiratory droplet and aerosol formation. However, there is now more evidence from observational studies where group singing preceded diagnosis in COVID-19 clusters. In observational studies, multiple routes of transmission (e.g., through respiratory droplets during prolonged and unprotected close contact, through aerosols at varying distances and touching common objects) may have contributed to disease spread.

In this rapid review, all of the studies investigated indoor exposures, or based experiments and models on indoor conditions; therefore, readers should use caution when extrapolating findings to outdoor scenarios which can be lower risk for COVID-19 transmission.

In summary, the extent to which group singing or playing wind instruments increases COVID-19 transmission remains unclear. However, organizers can mitigate potential transmission by ensuring musicians and audience members socially distance themselves, wear masks, wash their hands and avoid sharing equipment or materials. In addition, organizers can consider larger venues or practice spaces (to reduce crowding), outdoor settings, shortened performances, routine cleaning of surfaces and optimize ventilation.

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6. Echternach M, Gantner S, Peters G, Westphalen C, Benthaus T, Jakubaß B, et al. Impulse dispersion of aerosols during singing and speaking: a potential COVID-19 transmission pathway. Am J Respir Crit Care Med. 2020 Oct 16 [Epub ahead of print]. Available from: https://doi.org/10.1164/rccm.202009-3438LE

7. Becher L, Gena AW, Voelker C. Risk assessment of the spread of breathing air from wind instruments and singers during the COVID-19 pandemic [Internet]. Weimer: Bauhaus University Weimar; 2020 [cited 2020 Nov 16]. Available from: https://www.uni- weimar.de/fileadmin/user/fak/bauing/professuren_institute/Bauphysik/00_Aktuelles/Risk_assessm ent_of_the_spread_of_breathing_air_from_wind_instruments_and_singers_during_the_COVID- 19_pandemic_01.pdf

8. Netz RR, Eaton WA. Physics of virus transmission by speaking droplets. Proc Natl Acad Sci U S A. 2020;117(41):25209-11. Available from: https://doi.org/10.1073/pnas.2011889117

9. Bahl P, Doolan C, de Silva C, Chughtai AA, Bourouiba L, MacIntyre CR. Airborne or droplet precautions for health workers treating COVID-19? J Infect Dis. 2020 Apr 16 [Epub ahead of print]. Available from: https://doi.org/10.1093/infdis/jiaa189

10. Abkarian M, Mendez S, Xue N, Yang F, Stone HA. Speech can produce jet-like transport relevant to asymptomatic spreading of virus. Proc Natl Acad Sci U S A. 2020;117(41)25237-45. Available from: https://doi.org/10.1073/pnas.2012156117

11. Guo ZD, Wang ZY, Zhang SF, Li X, Li L, Li C, et al. Aerosol and surface distribution of severe acute respiratory syndrome coronavirus 2 in hospital wards, Wuhan, China, 2020. Emerg Infect Dis. 2020;26(7):1583-91. Available from: https://doi.org/10.3201/eid2607.200885

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 11 12. Alsved M, Matamis A, Bohlin R, Richter M, Bengtsson PE, Fraenkel CJ, et al. Exhaled respiratory particles during singing and talking. Aerosol Sci Technol. 2020;54(11):1245-8. Available from: https://doi.org/10.1080/02786826.2020.1812502

13. Mürbe D, Fleischer M, Lange J, Rotheudt H, Kriegel M. Aerosol emission is increased in professional singing. DepositOnce 14279 [Preprint]. 2020 Sep 03 [cited 2020 Nov 12]. Available from: https://doi.org/10.14279/depositonce-10375.3

14. Anfinrud P, Stadnytskyi V, Bax CE, Bax A. Visualizing speech-generated oral fluid droplets with laser light scattering. N Engl J Med. 2020;382(21):2061-3. Available from: https://doi.org/10.1056/NEJMc2007800

15. Asadi S, Wexler AS, Cappa CD, Barreda S, Bouvier NM, Ristenpart WD. Aerosol emission and superemission during human speech increase with voice loudness. Sci Rep. 2019;9(1):2348. Available from: https://doi.org/10.1038/s41598-019-38808-z

16. Kwon SB, Park J, Jang J, Cho Y, Park DS, Kim C, et al. Study on the initial velocity distribution of exhaled air from coughing and speaking. Chemosphere. 2012;87(11):1260-4. Available from: https://doi.org/10.1016/j.chemosphere.2012.01.032

17. Bahl P, de Silva C, Bhattacharjee S, Stone H, Doolan C, Chughtai AA, et al. Droplets and aerosols generated by singing and the risk of COVID-19 for choirs. Clin Infect Dis. 2020 Sep 18 [Epub ahead of print]. Available from: https://doi.org/10.1093/cid/ciaa1241

18. Loudon RG, Roberts RM. Singing and the dissemination of tuberculosis. Am Rev Respir Dis. 1968;98(2):297-300. Available from: https://www.atsjournals.org/doi/10.1164/arrd.1968.98.2.297?url_ver=Z39.88- 2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub++0pubmed&

19. Swinkels K. COVID-19 superspreading events around the world [Google Sheet] [Internet]. Mountain View, CA: Google; 2020 [cited 2020 Oct 28]. Available from: https://docs.google.com/spreadsheets/d/1c9jwMyT1lw2P0d6SDTno6nHLGMtpheO9xJyGHgdBoco/e dit#gid=1812932356

20. O'Keeffe J. COVID-19 risks and precautions for the performing arts [Internet]. Vancouver, BC: National Collaborating Centre for Environmental Health; 2020 [cited 2020 Nov 12]. Available from: https://ncceh.ca/documents/covid-19-risks-and-precautions-performing-arts

21. Weed M, Foad A. Rapid scoping review of evidence of outdoor transmission of COVID-19. medRxiv 20188417 [Preprint]. 2020 Sep 10 [cited 2020 Oct 28] Available from: https://doi.org/10.1101/2020.09.04.20188417

22. Charlotte N. High rate of SARS-CoV-2 transmission due to choir practice in France at the beginning of the COVID-19 pandemic. medRxiv 20145326 [Preprint]. 2020 Aug 05 [cited 2020 Oct 28]. Available from: https://doi.org/10.1101/2020.07.19.20145326

23. Hartmann A, Mürbe D, Kriegel M, Lange J, Fleischer M. Risk assessment of rehearsal rooms for choir singing regarding aerosols loaded with virus. DepositOnce 14279 [Preprint]. 2020 Jul 22 [cited 2020 Nov 12]. Available from: https://doi.org/10.14279/depositonce-10388

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 12 24. Lelieveld J, Helleis F, Borrmann S, Cheng Y, Drewnick F, Haug G, et al. Model calculations of aerosol transmission and infection risk of COVID-19 in indoor environments. medRxiv 20199489 [Preprint]. 2020 Oct 02 [cited 2020 Oct 28]. Available from: https://doi.org/10.1101/2020.09.22.20199489

25. Wei WE, Li Z, Chiew CJ, Yong SE, Toh MP, Lee VJ. Presymptomatic transmission of SARS-CoV-2 - Singapore, January 23-March 16, 2020. MMWR Morb Mortal Wkly Rep. 2020;69(14):411-5. Available from: https://doi.org/10.15585/mmwr.mm6914e1

26. Jaja IF, Anyanwu MU, Iwu Jaja CJ. Social distancing: how religion, culture and burial ceremony undermine the effort to curb COVID-19 in South Africa. Emerg Microb Infect. 2020;9(1):1077-9. Available from: https://doi.org/10.1080/22221751.2020.1769501

27. Furuse Y, Sando E, Tsuchiya N, Miyahara R, Yasuda I, Ko YK, et al. Clusters of coronavirus disease in communities, Japan, January-April 2020. Emerg Infect Dis. 2020;26(9):2176-9. Available from: https://doi.org/10.3201/eid2609.202272

28. Koizumi N, Siddique AB, Andalibi A. Assessment of SARS-CoV-2 transmission among attendees of live concert events in Japan using contact-tracing data. J Travel Med. 2020;27(5):taaa096. Available from: https://doi.org/10.1093/jtm/taaa096

29. Cheng VC-C, Wong S-C, Chuang VW-M, So SY-C, Chen JH-K, Sridhar S, et al. The role of community-wide wearing of face mask for control of coronavirus disease 2019 (COVID-19) epidemic due to SARS-CoV-2. J Infect. 2020;81(1):107-14. Available from: https://doi.org/10.1016/j.jinf.2020.04.024

30. Pung R, Chiew CJ, Young BE, Chin S, Chen MI, Clapham HE, et al. Investigation of three clusters of COVID-19 in Singapore: implications for surveillance and response measures. Lancet. 2020;395(10229):1039-46. Available from: https://doi.org/10.1016/s0140-6736(20)30528-6

31. Yong SEF, Anderson DE, Wei WE, Pang J, Chia WN, Tan CW, et al. Connecting clusters of COVID-19: an epidemiological and serological investigation. Lancet Infect Dis. 2020;20(7):809-15. Available from: https://doi.org/10.1016/s1473-3099(20)30273-5

32. Szablewski CM, Chang KT, Brown MM, Chu VT, Yousaf AR, Anyalechi N, et al. SARS-CoV-2 transmission and infection among attendees of an overnight camp - Georgia, June 2020. MMWR Morb Mortal Wkly Rep. 2020;69(31):1023-5. Available from: http://doi.org/10.15585/mmwr.mm6931e1

33. Streeck H, Schulte B, Kuemmerer B, Richter E, Hoeller T, Fuhrmann C, et al. Infection fatality rate of SARS-CoV-2 infection in a German community with a super-spreading event. medRxiv 20090076 [Preprint]. 2020 Jun 02 [cited 2020 Oct 28]. Available from: https://doi.org/10.1101/2020.05.04.20090076

34. Mangura BT, Napolitano EC, Passannante MR, McDonald RJ, Reichman LB. Mycobacterium tuberculosis miniepidemic in a church gospel choir. Chest. 1998;113(1):234-7. Available from: https://doi.org/10.1378/chest.113.1.234

35. Sacks JJ, Brenner ER, Breeden DC, Anders HM, Parker RL. Epidemiology of a tuberculosis outbreak in a South Carolina junior high school. Am J Public Health. 1985;75(4):361-5. Available from: https://doi.org/10.2105/ajph.75.4.361

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 13 36. Washko R, Robinson E, Fehrs LJ, Frieden TR. Tuberculosis transmission in a high school choir. 1998;68(6):256-9. Available from: https://doi.org/10.1111/j.1746-1561.1998.tb06351.x

37. Kar-Purkayastha I, Ingram C, Maguire H, Roche A. The importance of school and social activities in the transmission of influenza A(H1N1)v: England, April – June 2009. Euro Surveill. 2009;14(33):19311. Available from: https://doi.org/10.2807/ese.14.33.19311-en

38. Briscoe JH. Persistent streptococcal throat infection in a preparatory school for boys. Journal Hyg (Lond). 1985;95(3):671-6. Available from: https://doi.org/10.1017/s0022172400060770

39. Vienna Philharmonic Orchestra. Das philharmonische tagebuch: aerosolausstoßtest: geringes infektionsrisiko durch die verbreitung von atemluft von musikern [Internet]. Vienna: Vienna Philharmonic Orchestra; 2020 [cited 2020 Oct 27]. Available from: https://www.wienerphilharmoniker.at/orchester/philharmonisches- tagebuch/year/2020/month/4/blogitemid/1423/page/1/pagesize/20?fbclid=IwAR2wCggWqcd- Q_8Ewzr3E8rwX3_RxWKOpQXo3hMkDpag04O-YY9BDfPE8qQ

40. Spahn C, Richter B. Risk assessment of a coronavirus infection in the field of music [Internet]. Freiburg im Breisgau: Freiburg Institute for Musicians’ Medicine (FIM), University Medical Center and University of Music Freiburg; 2020 [modified 2020 Jul 17; cited 2020 Oct 27]. Available from: https://www.mh- freiburg.de/fileadmin/Downloads/Allgemeines/RisikoabschaetzungCoronaMusikSpahnRichter17.7.2 020Englisch.pdf

41. He R, Gao L, Trifonov M, Hong J. Aerosol generation from different wind instruments. J Aerosol Sci. 2021;151:105669. Available from: https://doi.org/10.1016/j.jaerosci.2020.105669

42. Parker AS, Crookston K. Investigation into the release of respiratory aerosols by brass instruments and mitigation measures with respect to covid-19. medRxiv 20165837 [Preprint]. 2020 Aug 04 [cited 2020 Oct 28]. Available from: https://www.medrxiv.org/content/10.1101/2020.07.31.20165837v1

43. Volckens J, Good N, Fedak K, Fontenot J, L'Orange C, Tanner K. Bioaerosol emissions and exposures in the performing arts: a scientific roadmap for a safer return from COVID19 [Internet]. Fort Collins, CO: Colorado State University; 2020 [cited 2020 Oct 28]. Available from: https://smtd.colostate.edu/wp-content/uploads/sites/34/2020/08/AerosolStudyPrelimResults.pdf

44. Lai K-M, Bottomley C, McNerney R. Propagation of respiratory aerosols by the vuvuzela. PLoS One. 2011;6(5):e20086. Available from: https://doi.org/10.1371/journal.pone.0020086

45. Kahler CJ, Hain R. Fundamental protective mechanisms of face masks against droplet infections. J Aerosol Sci. 2020;148:105617. Available from: https://doi.org/10.1016/j.jaerosci.2020.105617

46. Brandt L. Measurement of aerosols from brass and woodwind instruments playing 5 minutes in distances from 0.5 to 4 meter [Internet]. Odense: University of Southern Denmark; 2020 [cited 2020 Nov 12]. Available from: https://www.makingmusic.org.uk/sites/makingmusic.org.uk/files/Measurement%20of%20aerosol% 20from%20brass%20and%20woodwind%20instruments%20.pdf

47. Schwalje AT, Hoffman HT. Wind instrument aerosol in covid era - COVID-19 and horns, trumpets, trombones, euphoniums, tubas, recorders, flutes, oboes, clarinets, saxophones and bassoons

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 14 [Internet]. Iowa City, IA: University of Iowa; 2020 [cited 2020 Oct 27]. Available from: https://medicine.uiowa.edu/iowaprotocols/wind-instrument-aerosol-covid-era-covid-19-and-horns- trumpets-trombones-euphoniums-tubas-recorders

48. van Doremalen N, Bushmaker T, Morris DH. Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1. N Engl J Med. 2020;382(16):1564-7. Available from: https://doi.org/10.1056/NEJMc2004973

49. Riddell S, Goldie S, Hill A, Eagles D, Drew TW. The effect of temperature on persistence of SARS- CoV-2 on common surfaces. Virol J. 2020;17(1):145. Available from: https://doi.org/10.1186/s12985-020-01418-7

50. Chin AWH, Chu JTS, Perera MRA, Hui KPY, Yen H-L, Chan MCW, et al. Stability of SARS-CoV-2 in different environmental conditions. Lancet Microbe. 2020;1(1):e10. Available from: https://doi.org/10.1016/S2666-5247(20)30003-3

51. Denton M, Etherington C, Peckham D. 146 trombones - a potential source of recurrent Burkholderia cepacia complex infection? J Cystic Fibrosis. 2013;12 Suppl 1:S85. Available from: https://doi.org/10.1016/S1569-1993(13)60288-X

52. Corrao W. Trombone lung: a new cause of atypical Mycobacterium infection. Chest. 2014;145(3):111A. Available from: https://doi.org/10.1378/chest.1826469

53. Drover H, Douglas E, Harvey-Dunstan T, Gates S, Hyndes K. P139 Are wind instrument musicians at a greater risk of developing a chest infection when compared to the general UK population? Thorax. 2019;74(Suppl 2):A166-7. Available from: https://doi.org/10.1136/thorax-2019- BTSabstracts2019.282

54. Glass RT, Conrad RS, Kohler GA, Bullard JW. Evaluation of the microbial flora found in woodwind and brass instruments and their potential to transmit diseases. Gen Dent. 2011;59(2):100-7.

55. Okoshi K, Minami T, Kikuchi M, Tomizawa Y. Musical instrument-associated health issues and their management. Tohoku J Exp Med. 2017;243(1):49-56. Available from: https://doi.org/10.1620/tjem.243.49

56. Marshall B, Levy S. Microbial contamination of musical wind instruments. Int J Environ Health Res. 2011;21(4):275-85. Available from: https://doi.org/10.1080/09603123.2010.550033

57. Mobley J, Bridges C. Wind ensemble infectious disease risks: a microbiological examination of water key liquids in brass instruments. Tex Public Health J. 2015;67(2):16-8. Available from: https://cdn.ymaws.com/www.texaspha.org/resource/resmgr/docs/journal_files/tphj_volume_67_is sue_2.pdf

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 15 Appendix A. Search Strategy – Primary Literature

Search results reporting DATABASES SEARCHED

Database Date searched Records Duplicates removed by database Remaining

MEDLINE 10/26/2020 39 n/a 39

Embase 10/26/2020 25 n/a 25

RECORDS TOTALS

Records source Records

Records identified through database searching 64

Duplicates removed by database n/a

Duplicates removed by bibliographic management software 6

Total records after duplicates removed 58

Search strategies MEDLINE Ovid MEDLINE(R) ALL <1946 to October 22, 2020>

# Searches Results

1 *Music/ or ("wind instrument*" or "wind play*" or "wind musician*" or "brass 14256 instrument*" or "brass player*" or "brass musician*" or woodwind* or trumpet* or trombone* or euphonium* or tuba or tubas or tubaist* or flute or flutes or flutist* or flautist* or oboe or oboes or oboist* or "French horn*" or clarinet* or saxophon* or bassoon* or piccolo* or ((play* or instrument* or band or bands or music*) adj5 (recorder* or horn* or brass* or reed*)) or vuvuzela* or philharmonic or orchestra or "school band*").ab,kf,kw,ti.

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 16 # Searches Results

2 Singing/ or (sing or singing or singer* or choir* or choral or vocalist*).ab,kf,kw,ti. 6487

3 *Voice/ or *Speech/ or ((speech* or (talk* not "cross talk*") or yell or yells or yelling 24946 or scream* or cheer* or shout* or vocaliz* or vocalis*).ti. not medline.st.)

4 1 or 2 or 3 43977

5 Asymptomatic Infections/ or exp Communicable Diseases/ or Community-Acquired 357705 Infections/ or Infections/ or Respiratory Tract Infections/ or exp Coronavirus Infections/ or Pneumonia, Viral/ or Influenza, Human/ or Virus Diseases/ or ((infection or infections or infectious or communicab* or ((respiratory or "community acquired") adj3 (infect* or disease* or illness*)) or virus* or influenza or coronavir*).kf,kw,ti. not medline.st.)

6 Communicable Disease Control/ or Cross Infection/ or Disease Outbreaks/ or Disease 380359 Transmission, Infectious/ or Epidemics/ or Infection Control/ or Pandemics/ or tm.fs. or Virus Shedding/ or ((transmi* or spread* or infectivity or (infect* adj3 route*) or excret* or shed* or "cross infect*" or outbreak* or epidemic* or pandemic*).kf,kw,ti. not medline.st.)

7 Aerosols/ or Body Fluids/ or *Saliva/ or Mouth Mucosa/ or ((aerosol* or bioaerosol* 129099 or droplet* or ((body or bodies or mouth* or nose* or oral*) adj3 (fluid* or secretion* or secrete* or discharge* or mucosa or mucus)) or saliva*).kf,kw,ti. not medline.st.)

8 ("COVID-19" or "severe acute respiratory syndrome coronavirus 2" or "SARS-CoV- 31433 2").nm,ps,px,rs,rx.

9 Pandemics/ and Coronavirus Infections/ 30988

10 ("2019 corona virus" or "2019 coronavirus" or "2019 ncov" or "corona virus 19" or 65089 "corona virus 2019" or "corona virus 2019" or "corona virus disease 19" or "corona virus disease 2019" or "corona virus epidemic*" or "corona virus outbreak*" or "corona virus pandemic*" or "coronavirus 19" or "coronavirus 2019" or "coronavirus 2019" or "coronavirus disease 19" or "coronavirus disease 2019" or "coronavirus epidemic*" or "coronavirus outbreak*" or "coronavirus pandemic*" or "covid 19" or "covid 2019" or "new corona virus" or "new coronavirus" or "novel corona virus" or "novel coronavirus" or "novel human coronavirus" or "sars coronavirus 2" or "sars cov 2" or "sars cov2" or "sars like coronavirus" or "severe acute respiratory syndrome corona virus 2" or "severe acute respiratory syndrome coronavirus 2" or "severe specific contagious pneumonia" or "wuhan corona virus" or "wuhan coronavirus" or 2019ncov or covid19 or covid2019 or ncov or sarscov2 or "coronavirus response" or "corona virus response").ab,kf,kw,ti.

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 17 # Searches Results

11 ((pandemic* or novel or wuhan) adj3 (coronavirus* or "corona virus*" or 11287 betacoronavirus* or "beta coronavirus*" or "beta corona virus*" or pneumonia* or SARS or "severe acute respiratory syndrome")).ab,kf,kw,ti.

12 (pneumonia adj3 (coronavirus* or "corona virus*" or betacoronavirus* or "beta 1278 coronavirus*" or "beta corona virus*" or SARS or "severe acute respiratory syndrome")).ab,kf,kw,ti.

13 or/5-12 797832

14 4 and 13 317

15 exp Animals/ not (exp Animals/ not Humans/) 18782996

16 14 not 15 147

17 (202010* or 202009* or 202008* or 202007*).ez. 440001

18 16 and 17 39

EMBASE Ovid Embase <1974 to 2020 October 22> # Searches Results

1 wind instrument/ or musical instrument/ or ("wind instrument*" or "wind play*" or 2982 "wind musician*" or "brass instrument*" or "brass player*" or "brass musician*" or woodwind* or trumpet* or trombone* or euphonium* or tuba or tubas or tubaist* or flute or flutes or flutist* or flautist* or oboe or oboes or oboist* or "French horn*" or clarinet* or saxophon* or bassoon* or piccolo* or ((play* or instrument* or band or bands or music*) adj5 (recorder* or horn* or brass* or reed*)) or vuvuzela* or philharmonic or orchestra or "school band*").ti. or (("wind instrument*" or "wind play*" or "wind musician*" or "brass instrument*" or "brass player*" or "brass musician*" or woodwind* or trumpet* or trombone* or euphonium* or tuba or tubas or tubaist* or flute or flutes or flutist* or flautist* or oboe or oboes or oboist* or "French horn*" or clarinet* or saxophon* or bassoon* or piccolo* or ((play* or instrument* or band or bands or music*) adj5 (recorder* or horn* or brass* or reed*)) or vuvuzela* or philharmonic or orchestra or "school band*").ab,kw,ti. not embase.st.)

2 singing/ or (sing or singing or singer* or choir* or choral or vocalist*).ti. or ((sing or 6596 singing or singer* or choir* or choral or vocalist*).ab,kw,ti. not embase.st.)

3 (*speech/ or *oral communication/ or *vocalization/ or *public speaking/) and 12908 (speech* or speak* or (talk* not "cross talk*") or yell or yells or yelling or scream* or cheer* or shout* or vocaliz* or vocalis*).ti.

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 18 # Searches Results

4 (speech* or speak* or (talk* not "cross talk*") or yell or yells or yelling or scream* or 26171 cheer* or shout* or vocaliz* or vocalis*).ti. not embase.st.

5 1 or 2 or 3 22293

6 asymptomatic infection/ or communicable disease/ or infection/ or airborne 848261 infection/ or community acquired infection/ or respiratory infection/ or virus infection/ or exp Coronavirus infection/ or virus pneumonia/ or influenza/ or pandemic influenza/ or seasonal influenza/ or ((infection or infections or infectious or communicab* or ((respiratory or "community acquired") adj3 (infect* or disease* or illness*)) or virus* or influenza or coronavir*).kw,ti. not embase.st.)

7 communicable disease control/ or cross infection/ or disease transmission/ or 493566 bacterial transmission/ or virus transmission/ or epidemic/ or infection control/ or infection prevention/ or pandemic/ or tm.fs. or virus shedding/ or ((transmi* or spread* or infectivity or (infect* adj3 route*) or excret* or shed* or "cross infect*" or outbreak* or epidemic* or pandemic*).kw,ti. not embase.st.)

8 aerosol/ or bodily secretions/ or *mucus/ or *saliva/ or body fluid/ or ((aerosol* or 118250 bioaerosol* or droplet* or ((body or bodies or mouth* or nose* or oral*) adj3 (fluid* or secretion* or secrete* or discharge* or mucosa or mucus)) or saliva*).kw,ti. not embase.st.)

9 ("2019 corona virus" or "2019 coronavirus" or "2019 ncov" or "corona virus 19" or 59924 "corona virus 2019" or "corona virus 2019" or "corona virus disease 19" or "corona virus disease 2019" or "corona virus epidemic*" or "corona virus outbreak*" or "corona virus pandemic*" or "coronavirus 19" or "coronavirus 2019" or "coronavirus 2019" or "coronavirus disease 19" or "coronavirus disease 2019" or "coronavirus epidemic*" or "coronavirus outbreak*" or "coronavirus pandemic*" or "covid 19" or "covid 2019" or "new corona virus" or "new coronavirus" or "novel corona virus" or "novel coronavirus" or "novel human coronavirus" or "sars coronavirus 2" or "sars cov 2" or "sars cov2" or "sars like coronavirus" or "severe acute respiratory syndrome corona virus 2" or "severe acute respiratory syndrome coronavirus 2" or "severe specific contagious pneumonia" or "wuhan corona virus" or "wuhan coronavirus" or 2019ncov or covid19 or covid2019 or ncov or sarscov2 or "coronavirus response" or "corona virus response").kw,ti.

10 ((pandemic* or novel or wuhan) adj3 (coronavirus* or "corona virus*" or 3747 betacoronavirus* or "beta coronavirus*" or "beta corona virus*" or pneumonia* or SARS or "severe acute respiratory syndrome")).kw,ti.

11 (pneumonia adj3 (coronavirus* or "corona virus*" or betacoronavirus* or "beta 544 coronavirus*" or "beta corona virus*" or SARS or "severe acute respiratory syndrome")).kw,ti.

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 19

# Searches Results

12 *Coronavirus infection/ and ("2019 corona virus" or "2019 coronavirus" or "2019 1178 ncov" or "corona virus 19" or "corona virus 2019" or "corona virus 2019" or "corona virus disease 19" or "corona virus disease 2019" or "corona virus epidemic*" or "corona virus outbreak*" or "corona virus pandemic*" or "coronavirus 19" or "coronavirus 2019" or "coronavirus 2019" or "coronavirus disease 19" or "coronavirus disease 2019" or "coronavirus epidemic*" or "coronavirus outbreak*" or "coronavirus pandemic*" or "covid 19" or "covid 2019" or "new corona virus" or "new coronavirus" or "novel corona virus" or "novel coronavirus" or "novel human coronavirus" or "sars coronavirus 2" or "sars cov 2" or "sars cov2" or "sars like coronavirus" or "severe acute respiratory syndrome corona virus 2" or "severe acute respiratory syndrome coronavirus 2" or "severe specific contagious pneumonia" or "wuhan corona virus" or "wuhan coronavirus" or 2019ncov or covid19 or covid2019 or ncov or sarscov2 or "coronavirus response" or "corona virus response").ab.

13 *Coronavirus Infections/ and ((pandemic* or novel or wuhan) adj3 (coronavirus* or 9 "corona virus*" or betacoronavirus* or "beta coronavirus*" or "beta corona virus*" or pneumonia* or SARS or "severe acute respiratory syndrome")).ab.

14 *Coronavirus Infections/ and (pneumonia adj3 (coronavirus* or "corona virus*" or 2 betacoronavirus* or "beta coronavirus*" or "beta corona virus*" or SARS or "severe acute respiratory syndrome")).ab.

15 or/6-14 1357523

16 5 and 15 360

17 (202010* or 202009* or 202008* or 202007*).dd. 430863

18 16 and 17 27

19 (exp animal/ or animal experiment/) not exp human/ 5010684

20 18 not 19 25

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 20 Appendix B. Search Strategy – Grey Literature and Preprints

Search strategies WEB SEARCHES (GENERAL) - GENERAL Google Canada | https://www.google.ca/ Search Strategy Date Searched # Records Reviewed

"coronavirus" OR "covid-19" OR "sars" OR "severe acute 10/30/2020 50 respiratory syndrome" OR "ncov" "Karaoke" OR "sing" OR "singing" OR "singer" OR "singers" OR "choir" OR "choirs" OR "choral" OR "chorales" OR "chorale" OR "chorales" "outbreak" OR "superspreader" OR "super emitter" OR "superemitter" filetype:pdf

"coronavirus" OR "covid-19" OR "sars" OR "severe acute 10/30/2020 50 respiratory syndrome" OR "ncov" philharmonic OR orchestra OR "school band" OR "school bands" OR "marching band" OR "marching bands" OR "brass band" OR "brass bands" "outbreak" OR "superspreader" OR "super emitter" OR "superemitter" filetype:pdf

WEB SEARCHES (GENERAL) - PREPRINTS Google Canada | https://www.google.ca/ Search Strategy Date Searched # Records Reviewed

"coronavirus" OR "covid-19" OR "sars" OR "severe acute 10/30/2020 50 respiratory syndrome" OR "ncov" "wind instrument" OR "wind instruments" OR woodwind OR "wind player" OR "wind players" OR "wind musician" OR "wind musicians" "outbreak" OR "superspreader" OR "super emitter" OR "superemitter" OR "transmission" site:.medrxiv.org/*

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 21 Search Strategy Date Searched # Records Reviewed

"coronavirus" OR "covid-19" OR "sars" OR "severe acute 10/30/2020 50 respiratory syndrome" OR "ncov" "brass instrument" OR "brass instruments" OR "brass player" OR "brass players" OR "horn player" OR "horn players" OR "brass musician" OR "brass musicians" "outbreak" OR "superspreader" OR "super emitter" OR "superemitter" OR "transmission" site:.medrxiv.org/*

"coronavirus" OR "covid-19" OR "sars" OR "severe acute 10/30/2020 50 respiratory syndrome" OR "ncov" trumpet OR trombone OR euphonium OR tuba OR flute OR oboe OR "french horn" OR "french horns" OR clarinet OR saxophone OR bassoon OR piccolo OR vuvuzela "outbreak" OR "superspreader" OR "super emitter" OR "superemitter" OR "transmission" site:.medrxiv.org/*

WEB SEARCHES (GENERAL) - JURISDICTIONS Google Canada | https://www.google.ca/ Search Strategy Date Searched # Records Reviewed

"coronavirus" OR "covid-19" OR "sars" OR "severe acute 10/30/2020 50 respiratory syndrome" OR "ncov" "sing" OR "singing" OR "singer" OR "singers" OR "choir" OR "choirs" OR "choral" OR "chorals" OR "chorale" OR "chorales" OR "karaoke" "outbreak" OR "superspreader" OR "super emitter" OR "superemitter" site:.ca

"coronavirus" OR "covid-19" OR "sars" OR "severe acute 10/30/2020 50 respiratory syndrome" OR "ncov" "sing" OR "singing" OR "singer" OR "singers" OR "choir" OR "choirs" OR "choral" OR

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 22 Search Strategy Date Searched # Records Reviewed "chorals" OR "chorale" OR "chorales" OR "karaoke" "outbreak" OR "superspreader" OR "super emitter" OR "superemitter" site:.gov

"coronavirus" OR "covid-19" OR "sars" OR "severe acute respiratory syndrome" OR "ncov" "sing" OR "singing" OR "singer" OR "singers" OR "choir" OR "choirs" OR "choral" OR 10/30/2020 50 "chorals" OR "chorale" OR "chorales" OR "karaoke" "outbreak" OR "superspreader" OR "super emitter" OR "superemitter" site:.govt.nz

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 23 Search Strategy Date Searched # Records Reviewed

COVID-19 Transmission from Singing and Playing Wind Instruments – What We Know So Far 24 Citation Ontario Agency for Health Protection and Promotion (Public Health Ontario). COVID-19 transmission from singing and playing wind instruments – what we know so far. Toronto, ON: Queen’s Printer for Ontario; 2020. Disclaimer This document was developed by Public Health Ontario (PHO). PHO provides scientific and technical advice to Ontario’s government, public health organizations and health care providers. PHO’s work is guided by the current best available evidence at the time of publication.

The application and use of this document is the responsibility of the user. PHO assumes no liability resulting from any such application or use.

This document may be reproduced without permission for non-commercial purposes only and provided that appropriate credit is given to PHO. No changes and/or modifications may be made to this document without express written permission from PHO. Public Health Ontario Public Health Ontario is an agency of the Government of Ontario dedicated to protecting and promoting the health of all Ontarians and reducing inequities in health. Public Health Ontario links public health practitioners, front-line health workers and researchers to the best scientific intelligence and knowledge from around the world.

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