This month, a patient was brought to a doctor complaining of chest pain and was found to have contracted COVID-19. After ruling out other conditions, the doctor concluded that this was likely a residual symptom of the virus. This is an example of long COVID, or post-acute sequelae of COVID-19 (PASC), which is an umbrella term for “health consequences” that are present at least 4 weeks after an acute infection. Common symptoms of long COVID include fatigue, shortness of breath, exercise intolerance, “brain fog,” chest pain, cough, and loss of taste/smell. There is no diagnostic test or criteria that confirms this diagnosis, leading to varying estimates of prevalence that range from 5% to 30%.
Several risk factors have been identified for long COVID, including women, those who are older, those with preexisting psychiatric illness, and those who are obese. Other factors associated with long COVID include reactivation of Epstein-Barr virus (EBV), abnormal cortisol levels, and high viral loads of the coronavirus during acute infection. Vaccines have been shown to lower, but not entirely eliminate, the risk of long COVID, as have antivirals.
The recognition of long COVID has prompted many to wonder if it occurs with other infectious diseases, such as Lyme disease, infectious mononucleosis, and Ebola. Some experts suspect an individual human’s immune response may influence the development of post-acute symptoms, and further research is needed to understand the biological basis of this condition in order to diagnose patients, develop treatment regimens, and to prognosticate.