Expressing disease burden in a single measure allows for the comparison of health loss from different diseases. Such a comparison is important for prioritizing policies and resources to combat (infectious) diseases. A commonly used measure for disease burden is the disability-adjusted life year (DALY). Disease burden in DALYs represents a sum of lost healthy life years due to illness and disability (years lived with disability: YLD) and due to premature death (years of life lost: YLL). Detailed descriptions of the methods used can be found in a previous edition of the State of Infectious Diseases. This webpage presents estimates of DALYs for COVID-19 and influenza. The disease burden of the long-term effects after a SARS-CoV-2 infection, or the 'post-COVID syndrome,' is not included, regardless of whether the person had a mild COVID-19 infection or was hospitalized. A more comprehensive description of these two infectious diseases, and 35 other infectious diseases in the Netherlands, is published in the State of Infectious Diseases 2023 (in Dutch). 

COVID-19 highest disease burden, influenza in third place

In 2023, COVID-19 caused the highest disease burden, just as in 2022, with an estimated disease burden of 37,800 DALYs (95% CI 36,400-39,200). However, the number of DALYs due to COVID-19 has more than halved compared to 2022. The disease burden of COVID-19 is caused for 84% by premature death (31,600 DALYs of the total 37,800 DALYs). The total YLD was 6,150 (95% CI: 6,060-6,240) DALYs. When looking at the total disease burden of individuals who did not die, the burden due to mild cases is the largest. The number of DALYs due to COVID-19 was more than three times higher than the number of DALYs due to influenza, with 10,900 DALYs (95% CI 10,100-11,800). Influenza has the third-highest disease burden, behind legionellosis.

Table 1. Estimated annual disease burden in DALYs for influenza and COVID-19 (with 95% confidence intervals) in the Netherlands for influenza (respiratory season 2019/2020 to 2023/2024) and COVID-19 (Calendar Years 2019-2023).
Note: In the respiratory season 2020-2021, it was not possible to estimate the disease burden of influenza with the current methodology. 
 DALY  (95% confidence interval)
 20192020202120222023
COVID-19 207.000 (203.600-210.400)218.900 (215.300-222.600)93.800 (91.600-96.100)37.800 (36.400-39.200)
 2019/20202020/20212021/20222022/20232023/2024
Influenza4900 (4500-5300)NAa14.200 (12.600-16.000)9500 (8600-10.400)10.900 (10.100-11.800)

Figure 1. Average annual DALY, split by YLL (years of life lost due to mortality) and YLD (years lived with disability), in the Netherlands for influenza (respiratory season 2019/2020 to 2023/2024) and COVID-19 (Calendar Years 2019-2023).

In 2023, the number of YLDs and YLLs due to COVID-19 more than halved compared to 2022: from 7,000 and 86,800 in 2022 to 6,100 and 32,000 in 2023, respectively. For influenza, the number of YLDs and YLLs were 2,500 and 7,000 in 2022/2023 and 2,100 and 8,800 in 2023/2024.

Note: In the winter season 2020-2021, it was not possible to estimate the disease burden of influenza with the current methodology

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