What is long COVID?

More than 18 months since COVID-19 was first globally identified, scientists and practitioners in many areas of the medical field are continuing to encounter new insights about this pandemic event. As additional data becomes available, two major things are clear: one, our understanding about the virus is continually evolving and the situation will undoubtedly remain very fluid for some time. And two, the post-infection period does not always resolve within a short or even reasonable amount of time.

One of the focuses has been the development of chronic symptoms that affect a subset of patients who were infected with the virus, including those who appeared to have had relatively mild cases. Now recognized as long COVID (also known as long-hauler COVID, post-acute COVID-19 syndrome (PACS), and LTC-19), this novel disorder is marked by a myriad of lingering symptoms that have had life-changing impacts on the lives of many individuals. 
 
Experts note that while recovery times for an initial COVID infection can vary, long COVID refers to instances where symptoms persist for 90+ days. Long COVID is generally diagnosed when signs and symptoms of COVID that can't be explained by other causes are present 4 weeks after the initial infection.1 This condition could be afflicting could be up to 15 million people and we can see that these numbers are continuing to increase.
 
These symptoms, many that are neurological and which we will discuss in more detail in this series, vary from one person to the next. They can range from extreme fatigue and brain fog to memory loss, inability to concentrate, loss of smell and/or taste, and other issues that affect daily life for an estimated 25 to possibly 35% or more of all diagnosed COVID cases. And this appears to be unrelated to the severity of the original infection and even when the patient no longer tests positive for the virus or antibodies.
Preliminary reports and data about long COVID symptoms and patient experiences seem to share many of the same characteristics as that of other chronic illnesses we know to be associated with viral triggers, such as:  Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS); postural orthostatic tachycardia syndrome (POTS); additional forms of Dysautonomia; and Mast Cell Activation Syndrome (MCAS); and other conditions.
 
It’s important to keep in mind that the data regarding both COVID and long COVID is constantly incoming as we continue to learn more with each passing day. But, some experts and studies have shown more than half of the 235+ million people diagnosed worldwide could go on to suffer varying degrees of long COVID-related illness for months following an original infection.2
 
But for how long could these issues persist? Right now, we just don’t know, simply because not enough time has passed in order to determine when symptoms may cease. We will continue to stay abreast of the changing landscape and address patient symptoms and issues with all the resources we have available.
 
In hope and healing,
Dr. Suzanne Gazda
 
Coming up next in our series, “What are the signs and symptoms of long COVID?”
 
References:
 
1 Sisó-Almirall A, Brito-Zerón P, Conangla Ferrín L, et al. Long Covid-19: Proposed Primary Care Clinical Guidelines for Diagnosis and Disease Management. Int J Environ Res Public Health. 2021;18(8):4350. Published 2021 Apr 20. doi:10.3390/ijerph18084350
 
2 Groff D, Sun A, Ssentongo AE, et al. Short-term and Long-term Rates of Postacute Sequelae of SARS-CoV-2 Infection: A Systematic Review. JAMA Netw Open. 2021;4(10):e2128568. doi:10.1001/jamanetworkopen.2021.28568
https://www.psu.edu/news/research/story/how-many-people-get-long-covid-more-half-researchers-find/