Post-infection symptoms up to 24 months after COVID-19: a matched cohort study in Berlin, Germany 2025 Meierkord et al

Introduction: Long-term health consequences after mild COVID-19 are not well described. Our aim was to estimate their prevalence and describe the time course of signs and symptoms for a period of up to 24 months after SARS-CoV-2 infection.

Methods: We conducted a cohort study matched for age, sex, and test week among individuals who had attended the public COVID-19 test center at Charité—Universitätsmedizin Berlin, Germany. In early 2022, 576 former COVID-19 patients (>95% non-hospitalized) and 302 uninfected individuals responded to a questionnaire on retrospective monthly symptoms since the test date up to 24 months ago.

Results: Symptoms compatible with long COVID were present in 42.9% (247/576) of former COVID-19 patients, compared with 21.2% (64/302) in the uninfected group. In former patients, unadjusted odds ratios (OR) were highest for disturbed taste/smell (OR 9.1 [95% CI: 4.0–21.1]), memory difficulties (OR 5.1 [95% CI: 2.9–8.9]), and shortness of breath at rest (OR 4.5 [95% CI: 1.9–10.6]). In most former COVID-19 patients, symptoms occurred in one coherent period and resolved after a median of 6.5 months, while taste/smell disturbance and neurological/cognitive symptoms showed longer times until recovery. Factors associated with long COVID-compatible symptoms included hospitalization, symptomatic COVID-19 infection, low household income and female sex.

Conclusion: Post-infection symptoms in mild COVID-19 patients mostly persist for about half a year, but sometimes longer. Among uninfected individuals who never experienced COVID-19, 21.2% also reported long COVID-compatible symptoms. The current long COVID definition might require revision to prevent misclassification and over-reporting, and to improve diagnosis and prevalence estimates.

Open access

 

Symptoms they asked about:

• Fever
• Runny nose
• Cough
• Sweats
• Headache
• Migrane
• Loss of power in muscles
• Joint pains
• Exhaustion while resting
• Exhaustion while being minimal active
• Shortness of breath at rest
• Issues with sense of taste and/or smell
• Tiredness
• Loss of motivation
• Chest pain
• Sleep disturbance
• Concentration difficulties
• Anxiety
• Difficulties to remember things
• Depressive mood
• Heart palpitations
• Loss of hair
• Diarrhoea

 

Limitations (line breaks added):

Our study should be interpreted in the context of its limitations. First, our study used self-reported symptoms for a time period of up to 24 months as a basis of analysis which meant that in some cases, participants had to recall any signs and symptoms for a period of 2 years. Therefore, recall bias may be present.

Second, we asked participants to report symptoms monthly even when a symptom was only experienced for 1 day of the month, possibly allocating too much emphasis and importance to individual symptoms.

Third, we might have missed patients with severe forms of post-infection symptoms as they might not have been physically or cognitively able to answer our questionnaire, hence our study population is likely composed of mostly mild to moderate forms of post-infection symptoms.

 

If my memory is correct: They mentioned that some of the controls went for tests because they were close contacts. They also excluded controls that had had covid-like symptoms or positive tests during the period.

But I agree that it’s not an ideal way to get controls.