For this pandemic, there remain a lot of questions. We are getting some answers (though widely varying) for the quantifiable measures such as transmission rates, incubation times, and fatality rates. Other questions appear to have no real answers such as exactly what the animal reservoir is for this virus: even if we can eliminate the virus in the human population we still remain at risk of it returning unless we can eliminate the virus in the non-human reservoir.
A more pressing question is how is this virus transmitted from human to human. We are currently practicing things like frequent hand washing, wearing face masks, and keeping social distance such as the six-foot rule. Coincidental with the widespread encouragement and enforcement of these rules is what appears to be a slowing toward a constant rate of new cases and new deaths.
We may conclude that these measures are slowing the transmission. This suggests that the virus is spread through aerosols from the breath. However, we are seeing evidence of transmission to asymptomatic carriers. There appears to be even silent transmissions where the link between sick person and the next is an intermediate contact who never reports ssymptoms (possibly because the symptoms never appeared).
Transmission is not occurring from the usual routes of coughing or sneezing. It appears to be transmitted from just normal, relaxed, unremarkable breathing. If that is the case, I would expect that the transmission rates to be much faster than what we are seeing at around 2-3 infections per infected person.
Early on there were reports out of China that some people without any symptoms and feeling fine will suddenly collapse from lack of oxygen due to lung damage that was not accompanied by coughing or fever. I only heard anecdotal reports and never sought out details to see if investigation found that the person was repressing the acute symptoms. I state it here because I think it is possible for this virus to do substantial damage without causing any symptoms until it is too late. The point is that the person may have advanced infections without spewing droplets through coughing or spitting.
I suspect that normal breathing does not present a risk.
The recent decline in rates of new cases may be attributed to natural reduction due to changes in season or mutations within the virus itself. Attributing the reduction to social distancing may be incorrect, but I will assume that it is effective. The question is what is the route of new infections.
One thing I notice is that there are certain locations where the cases are very high. Outside of China those areas include places like areas in Italy, Spain, France, and New York City. Also, there cases appear to cluster among older adults especially those who are retired.
I have a theory that the transmission of this virus may be due to talking. Some of the places and situations above are prone to having more drawn out and animated conversations within large networks of acquaintances or even strangers. The talking itself may be what is spreading the virus.
In such prolonged conversations, the speakers will come closer in proximity to each other and the combination of the duration of the conversation and the variation in excitability during that conversation gives the virus its path literally from one mouth into the other.
One consequence of social distancing and isolation is that people are avoiding talking to each other, especially if they are not very familiar with each other. People standing in lines keeping 6 foot separation from those on either side are not going to initiate conversations. Even in more fleeting encounters, people tend to avoid conversations when before they may have exchanged a quick greeting and would have been more open to a light exchange in small talk.
The reduction in talking among each other is what may be reducing the spread of this virus. Conversely, the virus spread rapidly by exploiting people’s prior habits of talking with people they barely know and extending those conversations until some goal is accomplished. Certain communities, especially those among retirees may be prone to long periods of continuous conversations.
As we consider our continued policies to control the spread of this pandemic, the current policies of social distancing and isolation may be unnecessary and excessive. Perhaps all we need to do is to discourage people from talking to each other. The path of transmission for this virus may be human conversations (friendly or adversarial).
The COVID-19 virus may end up be better nicknamed the talking virus.