Impact of COVID-19 infection control measures on influenza-related outcomes in Hong Kong

ABSTRACT

Following the announcement of coronavirus disease 2019 (COVID-19) cases in Wuhan on 31 December 2019, government officials in Hong Kong recommended the wearing of face masks as a public infection control measure against the COVID-19 virus and curtail the impact of the concurrent influenza season. The present study evaluated the influenza-related outcomes between the influenza season 2019 and 2020 in Hong Kong as a result of these infection control measures. A Monte Carlo simulation model was designed to estimate the number of influenza cases, clinic visits, hospitalization, deaths, direct medical cost and disability-adjusted life-years (DALYs) for the season 2018–2019 and 2019–2020 in six age groups: 0–5 years, 6–11 years, 12–17 years, 18–49 years, 50–64 years and ≥65 years in Hong Kong. Model inputs were derived from public data and existing literature. The model findings showed significant reduction in influenza-related cases, clinic visits, hospitalization, and deaths in 2020 versus 2019 (p < 0.05). Influenza-related direct costs in all age-groups were significantly reduced by 56%-82% (p < 0.01) in 2020 versus 2019. DALYs were also significantly decreased by 58%-85% (p < 0.01). The direct cost and DALYs avoided in 2020 was the highest among the age group of 0–5 years with a cost-saving of USD593,763 (95%CI 590,730–596,796) per 10,000 population and a DALY reduction of 57.67 (95%CI 57.54–57.83) per 10,000 population. This study illustrated the reduction of all influenza-related outcome measures in Hong Kong as a result of the implementation of public infection control measures against COVID-19.

KEYWORDS:

• Seasonal influenza
• COVID-19
• face mask
• health economics
• disability-adjusted life-years

Acknowledgments

The author wishes to thank Dr. Celeste Ewig (School of Pharmacy, The Chinese University of Hong Kong) for proofreading the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author.