What an unpredictable disease COVID-19 is. On top of the 580,000-plus Americans who have died, and the many millions who have endured the disease and recovered, we have become aware that 20% to 40% of those who had the disease continue to suffer. Every day I see people who still experience fatigue, shortness of breath, brain fog, depression, insomnia, loss of smell and taste, etc. The question I keep hearing: When will it end? The answer is a resounding…I just don’t know!
For most diseases, the risks exist while you have the infection. You expect to recover and return to your “normal” life. COVID-19 carries with it the possibility of serious disease and death, but once recovered, there can be ongoing or new symptoms – even including some people who started with an asymptomatic case. These continuing symptoms can be severe, and their duration is indefinite. Please note that this is not the case for the annual flu. While many do indeed die from influenza (many fewer than from COVID), the flu has no “long hauler” syndrome.
Almost two-thirds of patients who experienced COVID pneumonia still show lung abnormalities six months after recovery. Worse, a number of these may suffer permanent lung damage.
Nearly one of four patients hospitalized with COVID have ongoing cardiovascular complications. These heart symptoms account for up to 40% of COVID deaths. A significant number of recently recovered COVID patients show heart abnormalities and ongoing myocardial inflammation.
One in three COVID survivors suffer from neurologic or psychiatric symptoms up to six months after infection. These symptoms include memory loss, various nerve disorders, anxiety, depression, post-traumatic stress disorder, brain-fog, substance abuse, and insomnia. Symptoms are present in all age groups, as well as in patients who were asymptomatic, treated at home, or hospitalized.
So, exactly what does a COVID infection do to cause these lingering or possibly permanent symptoms? The first possibility, especially for those with lung or cardiovascular complications, is that the disease directly damages various organs. However, a leading theory has to do with long-term immune activation. Previous viral infections like the SARS epidemic of 2003 give us some clues. The condition results from continuous activation of the immune system long after the infection has resolved - in essence, the immune system instructs the body to produce a persistent inflammatory response, which is resistant to treatment. (Chronic fatigue syndrome, for example, behaves like this.) This leading theory of long-term immune activation is under study with a new $1.5 billion grant to the National Institutes of Health.
Given all of this, when is a case of COVID-19 really over? Some COVID patients report significant improvement or complete resolution of long hauler symptoms with time, or even following vaccination. Others report improvement after a short course of steroids. As I tell my COVID-19 patients, they are the early history for a new disease, so time will tell.
All of us, including doctors and employers in particular, need an understanding of the short-term as well as these long-term consequences of COVID-19. What we do know for certain, unfortunately, is that this disease will remain with us for some time to come.