‘Super-spreaders’
Re “Normal choir practice turns deadly,” March 30
My heart goes out to the members of the Skagit Valley Chorale in Mount Vernon, Wash., who have seen their numbers decimated by COVID-19 after their March 10 practice. This should teach everyone how dangerous and easily transmitted this coronavirus is.
As a longtime choir singer, I have been missing our weekly rehearsal and Sunday morning services. I am being very careful, because as an asthmatic (under control) and a geezette (female geezer), I know I have several strikes against me.
After reading this article, I plan to be even more cautious and hygienic, leaving my house only to pull weeds in the garden and take out the blue barrel every week. Jean Koch
Los Angeles
I am fascinated by the mechanism of infection among the singers in Mount Vernon, because they said they took extra precautions during their March 10 practice, were all asymptomatic and avoided contact with one another.
A paper published in the scientific journal Nature in February 2019, “Aerosol Emission and Superemission During Human Speech Increase With Voice Loudness,” may help to explain the spread of COVID-19. The authors point out that a small fraction of individuals behaves as “speech superemitters,” consistently releasing an order of magnitude more particles than those of their peers.
The spread of COVID-19 among the singers suggests they may may be “super-spreaders” like the ones mentioned in the Nature article’s abstract:
“These results suggest that other unknown physiological factors, varying dramatically among individuals, could affect the probability of respiratory infectious disease transmission, and also help explain the existence of superspreaders who are disproportionately responsible for outbreaks of airborne infectious disease.”
Gershon Hepner, MD
Los Angeles
This article is very important because it alerts us to the fact that the coronavirus probably can spread by aerosols, which unlike micro-droplets remain suspended in the air for a period of time, and that asymptomatic infected people can transmit the virus to others by this mechanism.
I have been puzzled about how the virus could be highly infectious, even in the case of asymptomatic people, if micro-droplets produced through coughing and sneezing were the only airborne method of transmission.
The article cites a 1977 flu outbreak aboard a commercial plane that alerted epidemiologists to the fact that influenza could spread through the air. I am therefore surprised that aerosol transmission of the coronavirus was seemingly not seriously thought to be a possibility until now.
Gertrude Barden
Porter Ranch The writer is a retired clinical microbiologist.