COVID-19 in people with Cystic Fibrosis beyond the pre-omicron era: a prospective study with a specific focus on long COVID

Background: The long-term clinical consequences of COVID-19 in cystic fibrosis (CF) remain largely unexplored. This study aimed to assess the incidence of long COVID in a large population of people with CF. Methods: This prospective, multicentre study enrolled individuals with confirmed SARS-CoV-2 infection between July 2021 and October 2022. Data collected included clinical features prior to infection, symptoms during the acute phase, hospitalization and symptom persistence after 1 and 6 months. Long COVID was defined according to CDC criteria as persistence of at least one COVID-related symptom for one or more months after diagnosis. The mean variation of FEV1 recorded 6 months after acute infection was also evaluated. Results: A total of 1102 people with CF were recruited (median age: 18 years, 520 younger than 18). The infection was symptomatic in 90.1 % of cases. During the acute phase, 8 subjects required oxygen support; 31 were hospitalized, one patient required intensive care. Complications included one thromboembolic event and two episodes of myocarditis, but no patient died. Mean variation of FEV1 after 6 months from the infection was +1.8 % (95 % CI: 1.0-2.7). Long COVID was documented in 64 subjects (5.8 %, 95 % CI: 4.5-7.4) with a variety of symptoms which were still present in 12 cases 6 months after infection (1.1 %, 95 % CI: 0.6-1.9). Conclusions: In the omicron phase of the pandemic, COVID-19 was relatively mild and did not negatively impact pulmonary function after 6 months. Long COVID was observed at all ages, but extrapulmonary symptoms were more frequent and persistent in adults.