Learning More About Long COVID

The COVID-19 pandemic has been a painful and eye-opening experience in global public health. From lives lost to vaccine inequity, and deeply-rooted social disparities, the pandemic has taught us so many lessons that it’s often hard to know where to begin.

Perhaps one of the more insidious aspects of this novel coronavirus comes in the form of long-term effects. Often called “long COVID,” these symptoms exist after acute infection. The Centers for Disease Control and Prevention (CDC) defines long COVID as “a range of symptoms that can last weeks or months after first being infected with the virus that causes COVID-19 or can appear weeks after infection. Long COVID can happen to anyone who has had COVID-19, even if the illness was mild, or they had no symptoms. People with long COVID report experiencing different combinations of the following symptoms: tiredness or fatigue, difficulty thinking or concentrating (sometimes referred to as “brain fog”), headache, loss of smell or taste, dizziness on standing, etc.”

While there is much attention to those with persistent symptoms who were hospitalized due to severe disease, we are still desperately trying to understand the case for those who did not require hospitalization. A new study focusing on Danish patients addressed this very question. Utilizing a population-based cohort harnessing prescription, patient, and health insurance registries, the researchers reviewed patients with a positive or negative PCR test between February 27 to May 31, 2020.

The team reviewed outcomes related complications like persistent symptoms and certain prescription drug utilization. The authors reported that of the 10,498 individuals with SARS-CoV-2, they were able to review 8983 who were alive and not admitted to the hospital within 2 weeks of the positive test. “Compared with SARS-CoV-2-negative individuals, SARS-CoV-2-positive individuals were not at an increased risk of initiating new drugs (RD <0·1%) except bronchodilating agents, specifically short-acting β2-agonists (117 [1·7%] of 6935 positive individuals vs 743 [1·3%] of 57, 206 negative individuals; RD +0·4% [95% CI 0·1–0·7]; RR 1·32 [1·09–1·60]) and triptans (33 [0·4%] of 8292 vs 198 [0·3%] of 72,828; RD +0·1% [0·0–0·3]; RR 1·55 [1·07–2·25]). There was an increased risk of receiving hospital diagnoses of dyspnoea (103 [1·2%] of 8676 vs 499 [0·7%] of 76 728; RD +0·6% [0·4–0·8]; RR 2·00 [1·62–2·48]) and venous thromboembolism (20 [0·2%] of 8785 vs 110 [0·1%] of 78,872; RD +0·1% [0·0–0·2]; RR 1·77 [1·09–2·86]) for SARS-CoV-2-positive individuals compared with negative individuals, but no increased risk of other diagnoses.”

From this study and the results, the authors noted that in terms of severe post-acute complications from SARS-CoV-2 infection, there is a low relative risk for those who were not admitted to the hospital.

While there is still much to be learned of long haul COVID, we will need considerable resources and sustained funding to support future research. Moreover, as we learn about the prevalence of long COVID and the needs of those experiencing effects of infection, it will be imperative that resources are provided to those experiencing those symptoms. Research such as this is promising in that there is lower risk for long COVID, especially severe forms, for those who are not hospitalized with acute infection.