Acute Lower Respiratory Tract Disease remains a significant disease following the COVID19 pandemic

<bold>Background:</bold> Few studies have estimated total aLRTD burden and distribution of pneumonia and non-pneumonic lower respiratory tract infection (NPLRTI) overtime during and after the COVID-19 pandemic. <bold>Aims:</bold> To describe incidence of aLRTD and its subgroups in hospitalised adults Bristol, UK. <bold>Methods:</bold> A prospective cohort study of persons age ≥18y admitted to either of two acute care hospitals in Bristol, UK, from Aug20–Aug23. Patients were included if presenting with signs/symptoms or clinical/radiological aLRTD diagnosis. <bold>Results:</bold> 32438 aLRTD hospitalisations occurred: 15202 pneumonia, 11439 NPLRTI, 5343 non-infective, and 499 undifferentiated aLRTD cases. Pneumonia showed seasonal variation in all age groups, with a notably higher seasonal peak among older adults. NPLRTI weekly case rate appeared to increase during the last two study years, compared to Aug20-Aug21. Annual aLRTD incidence appeared stable over the three study years, averaging 15.0/1000 adults/y. Adults ≥65y had particularly high incidences of pneumonia and NPLRTI (Figure). The incidence of pneumonia and NPLRTI in ≥75y adults was 87.1 and 55.3 per 1000 people/y, respectively. <bold>Discussion</bold> During and after the COVID19 pandemic, aLRTD remained a substantial cause of hospitalisation. Older adults had particularly high disease burden across all aLRTD subgroups: both pneumonic and non-pneumonic infection contribute to disease burden. <bold>aLRTD incidence by age and subgroup</bold> <fig><object-id>erj;64/suppl_68/PA2200/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>