Dear Dr. Eva,

What is a super spreader and how many are there? Is there a way to recognize them?

Super scared

Dr. Eva,

Thank you for the clarification regarding social distancing.

Do we have actually have a list of what are the effects of the virus in our bodies? Do we know what are the worst symptoms?

Kind Regards,

Concerned Reader from the UK

Dear Dr. Eva,

What is an asymptomatic shedder? I know it’s not like my dog. It has something to do with the Covid virus.


Dear Readers,

Thank you for some excellent questions.

COVID-19 is an unusual virus in at least two different ways. Not only is there a lot of variation in how severe the disease can be in different people, there are also many different ways it can affect the body. The reasons the disease can affect people in such a variety of ways are unknown. Among other factors, the variation may be related to an infected person’s particular genetic make up, their underlying medical problems, and their behavior patterns such as smoking.

Let’s start with discussing the variation in how sick different people get.

Even though we think of COVID as a lung disease and lung problems are the commonest cause of death from COVID, only 20% (one in 5) of infected people will get pneumonia. Fourteen percent of infected people will become sick enough to need care in an intensive care unit. Just 5% (one in twenty) will have life-threatening disease, and 2% (one in fifty) will die. In other words, of each 100 people who become infected, only two will die and only one in five will need to be hospitalized. Eighty percent, four out of five, will not become seriously ill.

The great majority of serious disease from COVID occurs in people over 70, and especially in those over 80 years old. There been fewer deaths in young adults and very few in children. This low rate of severe disease is important to keep in mind in order to balance out our natural fear of this disease.

There is also great variation in the ways a person can get sick. The most common symptoms are fever, dry cough, and shortness of breath. Muscle aches, sore throat, and vomiting and diarrhea are also fairly common. Less frequently, people get rashes, kidney damage to the point of needing dialysis, and blood clots causing strokes and heart attacks. Some people get pinkeye and some lose their sense of taste and smell. Sometimes, a person can have barely noticeable infection, perhaps just a mild cough, and then develop

a severe form of the disease like a stroke.

Currently, we have no clear understanding of why people develop different forms of the disease and no way to predict who will develop which complications. It is known that some underlying diseases including kidney disease, lung disease, heart disease, and high blood pressure increase the risk of all the types of severe COVID-related disease. Smoking and being overweight increase the risk of severe disease as well.

Super spreaders are people in whom the COVID virus, for unknown reasons, makes exceptionally large amounts (millions) of virus copies. Strangely, despite their huge viral loads, super spreaders don’t all become sick. Some do become ill, but others can feel fine while infecting dozens of people around them. Currently there is no way to recognize a super spreader except by contact tracing, that is, finding and testing the people ill persons have been in contact with and trying to trace who they acquired the infection from. Typically, an infected person will infect 2 or 3 others. If one specific infected person has infected many more than that, they are a super spreader and should be isolated until blood tests show they are no longer producing the virus.

Asymptomatic shedders are people who become infected with the virus and can spread it to others without ever developing any signs of illness (symptoms) themselves. In that way, they are similar to some super spreaders, but unlike super spreaders, they do not produce huge numbers of vaccine copies and do not infect large numbers of people. Just like super spreaders, currently there is no way to recognize asymptomatic shedders except through contact tracing.

It would be great if super spreaders would turn bright red and asymptomatic shedders would turn neon yellow, but unfortunately this does not happen. That is why it is so important for us to continue with social distancing and masking. Since we have no way to know who we might catch the virus from, we have to assume we might be infected by anyone we meet.

Dr. Eva

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Dr. Eva Hersh, MD
Dr. Eva Hersh, MD
Eva Hersh is a family physician. Send your comments and questions to her by email at