ABSTRACT
Background: Post-COVID Syndrome (PCS) is an important sequela of COVID-19, characterised by symptom persistence >3 months, subacute symptom onset, and worsening of pre-existing comorbidities. The causes and public health impact of PCS are still unclear, not least for the lack of efficient means to assess the presence and severity of PCS. Method(s): COVIDOM is a population-based cohort study of PCR-confirmed cases of SARS-CoV-2 infection, recruited through local public health authorities in three German regions. Standardised interviews and in-depth onsite examinations were scheduled 6-12 months post infection. Based upon 12 long-term symptom complexes, we developed a comprehensive PCS severity score in a training cohort and validated the score in two independent subcohorts. Result(s): In the training sub-cohort (n=667, 56% female), 90% of participants were treated as outpatients for acute COVID-19. Neurological ailments (61.5%) and fatigue (57.1%) persisted most frequently. Across all sub-cohorts, higher PCS scores were associated with lower health-related quality of life (EQ-5D-5L-VAS/-index, all p<0.001). Similarly, participants with a higher PCS score consistently showed increased blood inflammatory markers and Ddimer as well as lower diffusing capacity in lung function (all p<0.01). Significant early predictors of the PCS score included the number and intensity of acute symptoms, resilience, and general anxiousness. Conclusion(s): PCS severity can be quantified by an easy-to-use score summarising individual disease burden and reflecting pathological processes. The PCS score promises to facilitate diagnosis of PCS, studies of its natural course, and of therapeutic interventions.
ABSTRACT
BACKGROUND: Chemosensory dysfunction (CD) has been reported as a common symptom of SARS-CoV-2 infection, but it is not well understood whether and for how long changes of smell, taste and chemesthesis persist in infected individuals. METHODOLOGY: Unselected adult residents of the German federal state of Schleswig-Holstein with Polymerase Chain Reaction (PCR)-test-confirmed SARS-CoV-2 infection were invited to participate in this large cross-sectional study. Data on the medical history and subjective chemosensory function of participants were obtained through questionnaires and visual analogue scales (VAS). Olfactory function (OF) was objectified with the Sniffin' Sticks test (SST), including threshold (T), discrimination (D) and identification (I) test as well as summarized TDI score, and compared to that in healthy controls. Gustatory function (GF) was evaluated with the suprathreshold taste strips (TS) test, and trigeminal function was tested with an ampoule containing ammonia. RESULTS: Between November 2020 and June 2021, 667 infected individuals (mean age: 48.2 years) were examined 9.1 months, on average, after positive PCR testing. Of these, 45.6% had persisting subjective olfactory dysfunction (OD), 36.2% had subjective gustatory dysfunction (GD). Tested OD, tested GD and impaired trigeminal function were observed in 34.6%, 7.3% and 1.8% of participants, respectively. The mean TDI score of participants was significantly lower compared to healthy subjects. Significant associations were observed between subjective OD and GD, and between tested OD and GD. CONCLUSION: Nine months after SARS-CoV-2 infection, OD prevalence is significantly increased among infected members of the general population. Therefore, OD should be included in the list of symptoms collectively defining Long-COVID.
ABSTRACT
PURPOSE: Over the course of COVID-19 pandemic, evidence has accumulated that SARS-CoV-2 infections may affect multiple organs and have serious clinical sequelae, but on-site clinical examinations with non-hospitalized samples are rare. We, therefore, aimed to systematically assess the long-term health status of samples of hospitalized and non-hospitalized SARS-CoV-2 infected individuals from three regions in Germany. METHODS: The present paper describes the COVIDOM-study within the population-based cohort platform (POP) which has been established under the auspices of the NAPKON infrastructure (German National Pandemic Cohort Network) of the national Network University Medicine (NUM). Comprehensive health assessments among SARS-CoV-2 infected individuals are conducted at least 6 months after the acute infection at the study sites Kiel, Würzburg and Berlin. Potential participants were identified and contacted via the local public health authorities, irrespective of the severity of the initial infection. A harmonized examination protocol has been implemented, consisting of detailed assessments of medical history, physical examinations, and the collection of multiple biosamples (e.g., serum, plasma, saliva, urine) for future analyses. In addition, patient-reported perception of the impact of local pandemic-related measures and infection on quality-of-life are obtained. RESULTS: As of July 2021, in total 6813 individuals infected in 2020 have been invited into the COVIDOM-study. Of these, about 36% wished to participate and 1295 have already been examined at least once. CONCLUSION: NAPKON-POP COVIDOM-study complements other Long COVID studies assessing the long-term consequences of an infection with SARS-CoV-2 by providing detailed health data of population-based samples, including individuals with various degrees of disease severity. TRIAL REGISTRATION: Registered at the German registry for clinical studies (DRKS00023742).