Influenza incidence overlapped with COVID-19 or under COVID-19 control measures

Azad Shokri; Ghobad Moradi; Farhad Moradpour; Amjad Mohamadi Bolbanabad; Fatemeh Younesi; Parisa Daftarifard; Ali Ebrazeh

doi:10.1002/iid3.672

Influenza incidence overlapped with COVID-19 or under COVID-19 control measures

Immun Inflamm Dis. 2022 Aug;10(8):e672. doi: 10.1002/iid3.672.

Authors

Azad Shokri¹, Ghobad Moradi¹, Farhad Moradpour¹, Amjad Mohamadi Bolbanabad¹, Fatemeh Younesi², Parisa Daftarifard³, Ali Ebrazeh⁴

Affiliations

¹ Social Determinants of Health Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran.
² Department of Health Services Management, Faculty of Management and Information, Iran University of Medical Sciences, Tehran, Iran.
³ English Language Research Center, South Tehran Branch, IAU, Tehran, Iran.
⁴ Department of Public Health, School of Public Health, Qom University of Medical Sciences, Qom, Iran.

Abstract

Introduction: COVID-19 pandemic caused infection when influenza was still prevalent. This study was conducted to examine influenza incidence overlapped with COVID-19 and the effect of the COVID-19 measures on influenza incidence as a proxy.

Methods: The routine sentinel surveillance data on COVID-19 and influenza was obtained from the national integrated care electronic health record system. Data were collected in 28 points from 11 months before the outbreak (from March 2019 to January 2020) and 17 months after the outbreak (February 2020 to June 2021).

Results: In Iran, the incidence rate of influenza was 51.1 cases per 100,000 populations in November 2019, while it was only 0.1 in November 2020. The average number of influenza cases specifically for the Kurdistan province during the seasonal flu peak in 2019-2020 was 2.5 cases per 100,000 populations, while the average of influenza cases in the preceding 4 years was 0.4 cases per 100,000 populations. In other words, the seasonal peak of influenza in Iran was significantly higher than that of previous and after years.

Conclusion: It seems that some of the nonpharmaceutical interventions (NPIs) used to control COVID-19 are effective against influenza epidemics and the results indicated a marked decline in the number of influenza cases may cause after the implementation of public health measures for COVID-19. The results showed the seasonal peak of influenza in Iran was significantly higher than that of previous years, so it seems that the influenza winter peak season (November 2019) overlapped with SARS-CoV-2 causing observed undetected infection during influenza winter peak.

Keywords: COVID-19; influenza; nonpharmaceutical interventions.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

COVID-19* / epidemiology
Humans
Incidence
Influenza, Human* / epidemiology
Influenza, Human* / prevention & control
Pandemics / prevention & control
SARS-CoV-2