O-016 Prevalence and Risk Factors of Long-Covid-19 Syndrome in Health Care Workers: A Multi-Centre Study From North-Eastern Italy, Orchestra Project Working Group

Introduction The impact of long-COVID-19 syndrome is still debated, being potentially influenced by residual confounders. This study investigated prevalence of long-COVID-19 symptoms among health care workers (HCWS) of four university hospitals from North-Eastern Italy: Trieste, Padua, Verona and Modena-Reggio Emilia. Methods During June 2022- August 2022, HCWs were surveyed on past COVID-19 infections, medical history and any persisting symptoms. Presence of any post-covid-19 symptoms at 30-60 days or 60+ days since recovery from acute COVID-19 was investigated by multivariable logistic regression. Results were expressed as adjusted odds ratio (aOR) with 95% confidence interval (95%CI). Results 5,432 HCWs returned the questionnaire; 2,387 were SARS-CoV-2 infected at least once, 230 two and 8 three times. Prevalence of long-COVID-19 after the first COVID-19 infection was 24.0% at 30-60 days versus 16.3% at 60+ days, and 10.5% against 5.5% after the second SARS-CoV-2 event, respectively. The most frequent post-COVID-19 symptoms were general (35.1%), ENT (21.8%) or pulmonary (21.0%), whereas symptoms persisting after recovery from acute disease were predominantly neurological (50.3%), general (40.9%) and psychological (40.9%). The main determinants of long-COVID-19 syndrome at 30-60 days were Alpha predominant transmission period (aOR=4.34; 3.25-5.79)), COVID-19 associated hospitalization (aOR= 3.14; 2.17-4.54)) or female sex (aOR=1.88; 1.18-2.98), followed by age>40, non-Caucasian race or BMI>25 or <18. Discussion Prevalence of long-COVID-19 was higher during the initial stages of the pandemic, when more virulent viral strains were circulating and vaccination were not available. Conclusions The risk of long-COVID-19 likely decreased inversely with herd immunity level. The high prevalence of persisting psychological/neurological symptoms questions possible predisposing factors to Long-COVID-19.