Background Long COVID is a complex, multi-system illness with the potential for a substantial impact on society, from increased health care costs to economic and productivity losses. Long COVID is an umbrella term with no consensus on definition. Long COVID burden estimations in Ireland are patchy and unavailable. We set out to estimate the burden of Long COVID symptom clusters in Ireland from March 2020 to February 2022.

Methods Data were obtained from the Central Statistics Office and the Health Protection and Surveillance Centre, Ireland. We modelled estimates of the proportion of individuals with Long COVID symptoms based on the Global Burden of Disease (GBD) Long COVID Study framework. Years Lived with Disability (YLDs) due to Long COVID symptom clusters were estimated by age and gender.

Results An estimated 1.2 million symptomatic SAR-CoV-2 infection was reported in Ireland between March 2020 and February 2022. Overall, 11.8% (95% UI 1.5 – 35.5%) of individuals who had symptomatic SARS-CoV-2 experienced Long COVID symptom clusters. 24,199 (95% UI 3,384 – 69,210) individuals [females: 16,063 (95% UI 2,316 – 45,442); males: 8,316 (95% UI 1,068 – 23,668)] experienced Long COVID symptom clusters in the first year, and 112,376 (95% UI 13,434 – 335,442) in the second year of the pandemic [females: 78,172 (95% UI 9,811 – 230,281); males: 34,204 (95% UI 3,624 – 105,161). YLDs attributable to Long COVID was 1,764 (95% UI 201 – 6,540) and 4,872 (95% UI 417 – 20,540) in the first and second year of the pandemic, respectively. Females experienced higher Long COVID burden [4,332 (95% UI 417 – 17,565)] than males [2,304 (95% UI 206 – 9,526)]. Females aged 25 – 44 years had the highest burden of Long COVID [1,360 (95% UI 119 – 5,696). Long COVID contributed 82.5% (95% UI 40.2% – 93.1%) of the total YLDs [8,040 (95% UI 1,459 – 29,106)] due to COVID-19 within the period.

Conclusion Long COVID estimates are crucially important for evidence-informed policymaking and developing a model of Long COVID care in Ireland. However, the full impact of Long COVID on population health and health care system will be clearer once a core set of health outcomes is developed internationally.