Jamestown Canyon Virus Disease: An Analytic Review of Human Cases Reported from 1982 Through 2022.

Reports of acute Jamestown Canyon Virus (JCV) cases have increased markedly over the last 15 years, associated with improved diagnostic testing protocols. Analysis of these cases and the criteria used for their diagnosis could benefit clinicians encountering this under-recognized disease. In the current study, we analyzed all published reports of acute human JCV infections in North America from the first in 1982 through 2022, including retrospective studies. A total of 50 reports with 416 cases of JCV were found. The primary illness associated with JCV infection involved the nervous system. Of reported encephalitis cases, the fatality rate was 2.4 percent in hospitalized patients. Of the cases with detailed patient outcome information, approximately 40 percent had prolonged hospitalization and/or long-term neurological sequelae. Although case incidence has increased over the last few decades, the overall time from admission/clinical onset to testing for JCV has not substantially changed from the 1980s. Confounding factors such as being immunocompromised, as well as previous or concurrent infections, were associated with a greater risk of more severe outcomes. Thus, the complexity of JCV infection with other conditions may impact the overall outcomes of JCV encephalitis.