Recovered not restored: Long-term health consequences after mild COVID-19 in non-hospitalized patients

BackgroundWhile the leading symptoms during coronavirus disease 2019 (COVID-19) are acute and the majority of patients fully recover, a significant fraction of patients now increasingly experience long-term health consequences. However, most data available focus on health-related events after severe infection and hospitalization. We present a longitudinal, prospective analysis of health consequences in patients who initially presented with no or minor symptoms of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection. Hence we focus on mild COVID-19 in non-hospitalized patients.MethodsWe included 958 patients with confirmed SARS-CoV-2 infection in this study. Patients were observed for seven months from April 6thto December 2nd2020 for long-term symptoms and SARS-CoV-2 antibodies. We identified anosmia, ageusia, fatigue or shortness of breath as most common, persisting symptoms at month 4 and 7 and summarized presence of such long-term health consequences as post-COVID syndrome (PCS). Predictors of long-term symptoms were assessed using an uni- and multivariable logistic regression model.FindingsWe observed 442 and 353 patients over four and seven months after symptom onset, respectively. Four months post SARS-CoV-2 infection, 8.6% (38/442) of patients presented with shortness of breath, 12.4% (55/442) with anosmia, 11.1% (49/442) with ageusia and 9.7% (43/442) with fatigue. At least one of these characteristic symptoms was present in 27.8% (123/442) and 34.8% (123/353) at month 4 and 7 post-infection, respectively. This corresponds to 12.8% patients with long-lasting symptoms relative to the initial total cohort (123/958). A lower baseline level of SARS-CoV-2 IgG, anosmia and diarrhea during acute COVID-19 were associated with higher risk to develop long-term symptoms.InterpretationThe on-going presence of either shortness of breath, anosmia, ageusia or fatigue as long-lasting symptoms even in non-hospitalized patients was observed at four and seven months post-infection and summarized as post-COVID syndrome (PCS). The continued assessment of patients with PCS will become a major task to define and mitigate the socioeconomic and medical long-term effects of COVID-19.FundingCOVIM:„NaFoUniMedCovid19”(FKZ: 01KX2021)Research in contextEvidence before this studyData about long-term health consequences after SARS-CoV-2 infection and COVID-19 is scarce and most available data describe health consequences in hospitalized patients during acute COVID-19. However, these studies do not take into account the vast majority of patients with a milder course of infection (WHO score1-3).Added value of this studyOur cohort consists of mostly mild COVID-19 cases that have been prospectively followed for a median time of 6.8 months. At least one trained physician critically reviewed the patients’ reported symptoms at each visit. We assessed SARS-CoV-2 IgG at each visit to correlate reported symptoms with serological data. At 4 months after SARS-CoV-2 infection, shortness of breath occurred in 8.6% (38/442), anosmia in 12.4% (55/442), ageusia in 11.1% (49/442), and fatigue in 9.7% (43/442) of patients. At least one characteristic symptom was present in 27.8% (123/442) and 34.8% (123/353) at months 4 and 7 post-infection, respectively. Symptoms were summarized as post-COVID syndrome (PCS). Relative to our initial total cohort (123/958), this corresponds to 12.8% patients with long-lasting symptoms. Lower baseline level of SARS-CoV-2 IgG, anosmia and diarrhea during acute COVID-19 were associated with higher risk of developing long-term symptoms.Implications of all available evidenceWe believe that our findings have important implications for the fields of infectious diseases and public health, because we show long-term health consequences may occur even after very mild COVID-19 in the outpatient setting. As up to 81% of all SARS-CoV-2 infected patients present with mild disease, it can be expected that PCS will affect a larger number of individuals than initially assumed, posing major medical, social and economic challenges.