Post-infectious syndromes in the post-pandemic phase among the German general population

BACKGROUND: Persistent symptoms after a respiratory infection can impair daily life, as has been shown, for example, for "long COVID." In this study, we determined the frequency and impact of symptoms that persisted for 12 weeks or more after a respiratory infection. A further endpoint was health care utilization for such symptoms in the general population. METHODS: A cross-sectional study was conducted within the population-based digital cohort DigiHero in Germany (DRKS00025600). 39.3% of invited participants responded by completing an online questionnaire. 46 915 adults were included in the analysis. Participants were asked about symptoms that persisted 12 weeks or longer after a respiratory infection between September 2024 and August 2025. RESULTS: 48.3% of participants (95% confidence interval: [47.9; 48.8]) reported having had at least one respiratory infection during the study period. Among them, 18.8% [18.3; 19.3] stated that they still had symptoms 12 weeks or more afterward. The frequency of persistent symptoms was higher in older persons (13.1% for ages 20 to 29, 21.4% for ages 60 to 69). Most (86.8%) of those affected reported at least moderate functional impairment, and 57.9% consulted a physician. The pathogen causing the original infection was known for 24.3% of those reporting persistent symptoms: there were 483 cases of SARS-CoV-2 infection, 102 of influenza, and 36 of RSV. The symptom duration, functional impairment, and symptom pattern were similar after infection with SARS-CoV-2 and influenza. The most common symptoms in all pathogen groups were impaired physical performance, shortness of breath, rapid exhaustion, and fatigue. CONCLUSIONS: Persistent symptoms after respiratory infections are common and similar across pathogens in frequency and severity.