Influenza Virus Surveillance from the 1918 Influenza Pandemic to the 2020 Coronavirus Pandemic in New York State, USA

A historical perspective of more than one hundred years of influenza surveillance in New York State demonstrates the progression from anecdotes and case counts to next-generation sequencing and electronic database management, greatly improving pandemic preparedness and response. Here, we determined if influenza virologic surveillance at the New York State public health laboratory (NYS PHL) tests sufficient specimen numbers within preferred confidence limits to assess situational awareness and detect novel viruses that pose a pandemic risk. To this end, we analyzed retrospective electronic data on laboratory test results for the influenza seasons 1997-1998 to 2021-2022 according to sample sizes recommended in the Influenza Virologic Surveillance Right Size Roadmap issued by the Association of Public Health Laboratories and Centers for Disease Control and Prevention. Although data solely from specimens submitted to the NYS PHL were insufficient to meet surveillance goals, when supplemented with testing data from clinical laboratories participating in surveillance programs, the recommended surveillance goals were achieved. Despite the sudden decline in influenza cases in 2020-2021, impacted by the COVID-19 mitigation measures, the dramatic increases in influenza cases surrounding the coronavirus pandemic reveal that influenza remains a national and international public health threat. Sample submissions to public health laboratories must be encouraged to facilitate monitoring for emerging viruses and preparedness for another pandemic.