Incidence and severity of SARS-CoV-2 infections in people with primary ciliary dyskinesia
Authors: Pedersen Eva SL , Schreck Leonie D , Goutaki Myrofora , Bellu Sara , Copeland Fiona , Lucas Jane S , Zwahlen Marcel ,   COVID-PCD patient advisory group, Kuehni Claudia E 
Published: October 2022

AbstractImportanceEarly in the COVID-19 pandemic, chronic respiratory disease was considered a risk factor for severe COVID-19 disease. Studies have confirmed a higher risk of intensive care unit admission and mortality in people with chronic pulmonary obstructive disease and cystic fibrosis, but there is little data in people with primary ciliary dyskinesia (PCD).ObjectiveTo study incidence of SARS-CoV-2 and its risk factors in people with PCD from May 2020 to May 2022. We also describe the severity of COVID-19 symptoms in this population and factors associated with severity.Design, setting, and participantsWe used data from COVID-PCD, an international participatory cohort study following people with PCD through the COVID-19 pandemic. The study is based on self-reported weekly online questionnaires, available in five languages, adapted to children, adolescents, and adults. COVID-PCD invites people with PCD of any age to participate.ExposuresSARS-CoV-2Main OutcomesIncidence of reported positive test of SARS-CoV-2 and reported severity of symptoms.ResultsBy May 2022, 728 people with PCD participated (40% male, median age 27 years; range 0-85). The median weeks of follow-up was 60 (range 1-100). Eighty-seven (12%) reported a SARS-CoV-2 infection at baseline or during follow-up and 62 people reported an incident SARS-CoV-2 infection during 716 person-years of follow-up (incidence rate 9 per 100 person years; 95%CI 7-11). Using Poisson regression, we found that age above 14 years was associated with lower risk of infection (IRR 0.42, 95%CI 0.21-0.85) but the strongest predictors were exposure to Delta (IRR 4.52, 95%CI 1.92-10.6) and Omicron variants (IRR 13.3, 95%CI 5.2-33.8) compared to the original strain. Severity of disease was mainly mild; 12 (14%) were asymptomatic and 75 (86%) had symptoms among whom 4 were hospitalized. None needed intensive care and nobody died. Using Poisson regression, we found that comorbidity (IRR 1.93, 95%CI 1.40-2.64) and being infected during the period when the Delta variant was predominant (IRR 1.43, 95%CI 1.07-1.92) were associated with more reported symptoms.Conclusion and RelevancePeople with PCD do not seem to have a higher incidence of SARS-CoV-2 infections nor higher risk of severe COVID-19 disease than people from the general population.Key PointsQuestionWhat is the incidence and severity of COVID-19 in people with primary ciliary dyskinesia and which factors are associated with reporting a SARS-CoV-2 infection and risk of severe disease?FindingsThis international cohort of 728 people with primary ciliary dyskinesia followed for two years during the COVID-19 pandemic found a low incidence of reported SARS-CoV-2 in people with primary ciliary dyskinesia and mainly mild disease. The strongest predictor of incidence and severity was virus variant.MeaningPeople with PCD do not seem to have a higher incidence of SARS-CoV-2 infections nor higher risk of severe COVID-19 disease than people from the general population.