From early on in the COVID pandemic, public health officials have been intently focused on asymptomatic or pre-symptomatic spread of the disease. The assumption that people without symptoms are major spreaders of the disease is the basis for most of the precautions about which we are constantly reminded. But in their zeal to warn about asymptomatic transmission, officials have neglected warning people that studies have consistently found that at least half the transmission is caused by people with symptoms.
A recent contact tracing study by the CDC of an outbreak that began at a wedding reception in Maine is a good illustration. According to the study1, an infected person attended a wedding reception with 55 guests. Thirty people that were at the reception, as either guests or support staff, ultimately came down with COVID. The study found that those thirty people transmitted the disease to another 27 people with whom they had regular contract, e.g., their family members.
From the initial 57 cases, the study was able to trace a total 177 cases which resulted in seven fatalities. The study was clearly intended to be a cautionary tale about attending indoor events, noting that the guests did not maintain social distancing and did not wear masks.
But the study also showed the importance of symptomatic transmission. Of those in the initial group, one person worked at a correctional facility and another at a long-term care facility. Both of those patients developed symptoms and went to work after the onset of symptoms. Those two patients were responsible for 82 cases at the correctional facility and 38 cases at the long-term care facility. Six of the seven fatalities occurred at the long-term care facility.
In other words, 68% of the cases and 86% of the fatalities were the direct result of transmission after the onset of symptoms by two individuals who went to work instead of staying home. If you go to work sick, you are not doing yourself, your company or your community any favors.
And this is not just a message for employees. Employers need to encourage their employees to stay home when they are sick. Frequently that will mean more generous sick pay policies. For hourly employees, many of whom live paycheck-to-paycheck, staying home means not having money to pay their rent or feed their families. Employers need to make sure their employees are not be forced to choose between paying the rent and coming in sick.
For most of my business career, going to work when you were sick was not only acceptable, it was admired. It showed your devotion to your job, that you could soldier on. It was stupid then and doubly so now. If you are sick, and especially if you have any COVID symptoms, just stay home. And if you are an employer, make it easy for your employees to do so.
If we could eliminate symptomatic transmission, which is actually much easier than preventing asymptomatic transmission, we could cut the transmission rate in half, maybe more. So, if you are in the media or a healthcare spokesperson, please mention that people should stay home when sick at least as often as you tell us to socially distance, wear masks, and wash our hands.
Note 1 – For the purposes of this discussion I am accepting the conclusions of the contact tracing at face value, although there is some reason to be skeptical about some of its conclusions. For example, the study concludes that one person at the wedding reception was responsible for all of the subsequent infections that occurred in those that attended. However, not everyone was tested prior to the event, so it impossible to say that there was only one person at the reception that was infected. It is equally possible that an outbreak had started in the community prior to the reception and several people who attended were already infected. Nonetheless the subsequent spread shows the role that symptomatic spread plays in community transmission.