Let's Talk: Long COVID Infection

The disease spectrum of COVID 19 is variable, ranging from asymptomatic to fatal infection, and symptoms can persist for anywhere from 10 to even 28 (or more) days.

Prospective studies have been done on this topic, some of which will be discussed below.

The case definition of Long COVID is tentatively a collection of symptoms that develop during or following a confirmed or suspected case of COVID-19, and which continue for more than 28 days.

Distribution of symptom duration

Risk factors identified for this Long COVID infection are:

1. Women > Men

2. Generally <70 years, though risk escalated as age advanced

3. All socioeconomic groups

4. More likely to be hospitalized

5. Asthma as a comorbid condition

Frequency of symptoms

The most common symptoms experienced were Fatigue and Intermittent Headaches, followed by respiratory symptoms.

Where these symptoms were present within the first week of infection, they were predictive of long COVID.

Symptom duration (Long COVID)

The Long COVID trajectory was assessed via symptom severity vs average number of symptoms over time. The probability of “severe” and “very severe” symptoms peaked during acute infection (<28 days), while the probability of “moderate” and “mild” rose gradually thereafter.

Symptom correlation (Short/Long COVID)

Kaplan Meier estimates of disease

Post Exertional Malaise or a worsening or relapse of symptoms after physical or mental activity during COVID-19 recovery occurred in >80% of patients, and at varying times.

Post Exertional Malaise

Relapses of symptoms can occur irregularly and in response to various triggers (Physical/Mental activity, Exercise, Stress).

Relapses of COVID

The reduced work capacity because of cognitive dysfunction, in addition to other debilitating symptoms, translated into the loss of hours, jobs, and ability to work relative to pre-illness levels. Additionally only a few recovered respondents had Fatigue Assessment Scores ranked as “no fatigue”. This could suggest that some respondents who reported that they were no longer experiencing symptoms considered any lingering effects as part of their new health baseline.

References:

• Davis, Hannah E., et al. "Characterizing long COVID in an international cohort: 7 months of symptoms and their impact." Available at SSRN 3820561 (2021).

• Sudre, Carole H., et al. "Attributes and predictors of long COVID." Nature medicine 27.4 (2021): 626-631.