Powassan Virus in the United States: An AI-Integrative One Health Scoping Review of Ecological Drivers, Zoonotic Interactions, Symptom Profiles, and Public Health Implications
Open Access
- 31 August 2026
- journal article
- review article
- Published by MDPI AG in Infectious Disease Reports
- Vol. 18 (5) , 96
Abstract
Background: Powassan virus (POWV) is the only tick-borne encephalitis-group flavivirus endemic to the United States (U.S.) and is an increasingly serious public health threat. Reported U.S. cases remain relatively few but have grown steadily—from fewer than two annually before 2005 to a record 60 in 2024—and neuroinvasive disease carries a 10–15% case fatality with lasting neurological sequelae in roughly half of the survivors. Examining POWV through a One Health lens, we conducted a scoping review of its ecological and zoonotic drivers, its interactions with co-circulating tick-borne pathogens, its full clinical spectrum, and its distinction from other tick-borne diseases. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidance, we searched PubMed/MEDLINE, U.S. Centers for Disease Control and Prevention (CDC) surveillance databases, state health-department publications, and vetted public-health news through early 2026. The review was conducted as an AI-integrative partnership among the authors, the Global Infectious Diseases and Epidemiology Online Network (GIDEON) database, and Claude (Anthropic), enabling a synthesis of human-curated archival records collected over six years alongside the published literature; this yielded over 200 sources, almost half unavailable through an AI search alone. Results: POWV is maintained in a sylvatic cycle involving I. scapularis ticks, small-mammal reservoirs, and incidental human spillover. Its clinical spectrum spans asymptomatic seroconversion to fatal meningoencephalitis; prodromal fever, headache, vomiting, and fatigue may progress to encephalitis, seizures, aphasia, cranial-nerve palsies, paralysis, and ataxia—the most severe neurological syndrome among U.S. tick-borne diseases. Cases cluster in the northeastern and Great Lakes states, with older males disproportionately affected, while viral evidence extends to the mid-Atlantic, southern, and western regions. POWV is distinguished by its flaviviral etiology, short (as little as 15 min) transmission window, absence of a characteristic rash, and complete antibiotic resistance. Of the 48 states surveyed, only 7 published POWV data. Conclusions: POWV is an escalating One Health threat driven by expanding vector tick ranges, land-use and climate change, and wildlife–human interface dynamics. Enhanced cross-sector surveillance integrating human, animal, and environmental monitoring, alongside improved public-health data reporting, is urgently needed.Keywords
This publication has 147 references indexed in Scilit:
- Human antibodies in Mexico and Brazil neutralizing tick-borne flavivirusesCell Reports, 2024
- Tick-Borne Illnesses in Emergency and Wilderness MedicineEmergency Medicine Clinics of North America, 2024
- Cerebrospinal fluid metagenomics has greatest added value as a test for Powassan virus among patients in New England with suspected central nervous system infectionDiagnostic Microbiology and Infectious Disease, 2024
- Background seropositivity to Jamestown Canyon virus can lead to diagnostic confusionDiagnostic Microbiology and Infectious Disease, 2023
- Tick bite risk factors and prevention measures in an area with emerging Powassan virus diseasePublic Health Challenges, 2023
- Detection of multiple tick-borne pathogens in Ixodes scapularis from Hunterdon County, NJ, USACurrent Research in Parasitology & Vector-Borne Diseases, 2023
- Powassan virus encephalitis: Single center experience from capital district of New YorkThe American Journal of the Medical Sciences, 2022
- Balanced T and B cell responses are required for immune protection against Powassan virus in virus-like particle vaccinationCell Reports, 2022
- Powassan Encephalitis and Colorado Tick FeverInfectious Disease Clinics of North America, 2008
- Outbreak of Powassan Encephalitis—Maine and Vermont, 1999-2001JAMA, 2001