Dr. Roach: Long COVID refers to symptoms, not transmission of virus

Keith Roach
To Your Health

Dear Dr. Roach: Can you elaborate on “long COVID”? Specifically, do people experiencing long COVID carry the virus for an extended period? Are they contagious during long COVID, or does the term refer to lingering symptoms but not necessarily testing positive?


Dr. Keith Roach

Dear S.E.: People with normal immune systems are almost never contagious after about 10 days following the onset of symptoms of COVID-19. The greatest period of contagion is during the two days before onset of symptoms through the day after they start, which is why masking is so important. People can be highly contagious without even knowing they have the disease. People with severe immune deficiency may be contagious for a longer period of time, so testing to make sure they are negative and consultation with an expert is advisable.

“Long COVID” refers to persistent symptoms after the virus is gone, long past the infectious period. There is no evidence that people with long COVID are infectious for longer times than people who have mild or no symptoms.

There are many viruses that may continue to cause symptoms long after the acute period. Some viruses may cause damage to various tissues and organs – polio is a classic example. More than 99% of people have just a mild cold symptom with polio and get completely better, but a sliver of people will have damage to the nerves and develop muscle paralysis, sometimes fatally. It took many years to work out the mechanism of how polio causes these long-term symptoms; likewise, how COVID causes the long-term symptoms it causes is not yet well understood.

The incidence of long COVID varies by study, but the lowest number published I have seen is 10% of people continuing to have symptoms for three months after infection.

Many organ systems can be affected long-term by COVID-19, but fatigue, “brain fog,” sleep disturbances, chest discomfort and shortness of breath are some of the most common symptoms people with long COVID will notice.

I am continually surprised by people who won’t take the vaccine out of fear of it causing possible long-term side effects. This just hasn’t been seen, despite 5 billion doses administered worldwide, and despite there being 300 years of experience with vaccines. No vaccine (other than live vaccines) has ever had long-term complications that haven’t shown up right away. Those who remain unvaccinated don’t seem to realize that they risk not only severe disease and death from COVID-19, but also the possibility of long-term debilitating symptoms.

Dear Dr. Roach: Would a copper-infused mask be effective against the flu or COVID-19?


Dear J.A.: All masks reduce transmission of COVID-19. Masks have variable effectiveness for the wearer, but may be more important to stop transmission from the wearer, if they are infected and don’t know it. The best mask remains the N95 mask, but surgical masks and fabric masks made from two layers of cotton and one layer of synthetic material provided outstanding protection.

Copper has antiviral properties, but it is not clear whether adding copper to a mask makes it more effective. I think the type of material used and how well it fits are more important than whether there is copper inside it.

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