Leveraging Lyme Disease Surveillance to Simulate Powassan Virus Prevalence.

Powassan virus (POWV), a tick-borne flavivirus, poses a public health risk with an estimated case fatality rate of approximately 10%. Its limited surveillance results in underreporting. Using Lyme disease data as a proxy, we developed an exploratory simulation study that estimated 4649 POWV cases in the United States from 2018 to 2022, as opposed to 156 reported cases. We further estimated mortality rates (0.2%-1%), which were lower than reported rates (4.8%-21%). These discrepancies suggest that POWV cases go undetected, likely due to asymptomatic and mild to moderate presentations. Our findings emphasize the need for enhanced surveillance to accurately assess the public health impact of POWV.