In the U.S., the number and percentage of medical visits where influenza-like illness (ILI) is reported is the main way flu activity is measured. According to the U.S. CDC, “ILI is defined as fever (temperature of 100°F [37.8°C] or greater) and a cough and/or a sore throat without a known cause other than influenza.” The percentage of medical visits that are for ILI is an important way to measure the burden of influenza on the healthcare system.
The 2020-2021 flu season in the United States is the mildest since at least 2009-2010, which is thought to be the result of widespread physical distancing targeted at COVID-19. This has also been the case in Virginia: the percent ILI for 2020-2021 is also the lowest since at least 2009-2010 — see the “ILI” tab here. The peak percent ILI in Virginia during 2020-2021 was 1.8% in epidemiological week one. The highest peak percent ILI in Virginia since 2009-2010 was 14.1% during epidemiological week forty-two of the 2009-2010 flu season.
What will be the weekly peak percent of medical visits that are for influenza-like illness (ILI) in Virginia during the 2021-2022 flu season?
This will resolve on 1 June 2022 as the weekly peak percent ILI during the 2021-2022 flu season in Virginia as reported by the VDH Influenza Surveillance unit.
If the peak percent ILI exceeds 30%, this resolves as “>30”.
If VDH ceases to track this information, this question resolves ambiguous.