Case Presentation: A 55-year-old male from Brooklyn, NY with insulin-dependent diabetes and dental abscess (s/p I&D 9 days prior) presented to an outside hospital with 3 days of fevers, headaches, persistent mouth pain, and altered mental status. He was transferred to our hospital on day 3 for Oral and Maxillofacial Surgery (OMFS) consultation. The patient’s wife reported a progressive change in his mentation (baseline AAOx3, now AAOx1), gait unsteadiness, and visual hallucinations. He denied recent illness, sick contacts, or travel outside of New York City (NYC). Vital signs upon admission: T 102, HR 107, BP 129/76. Exam was unremarkable with the exception of a nonfocal neuro exam (limited by cooperation, gait not assessed) with no nuchal rigidity or meningeal signs and notable left cheek swelling. Admission labs showed a leukocytosis (WBC 16.2), and he was started on vancomycin, ampicillin, and ceftriaxone for presumed bacterial meningitis. CT head and neck was unremarkable, and OMFS saw no active tooth infection. Blood cultures finalized as no growth. The patient underwent lumbar puncture (LP), with CSF results revealing a lymphocytic pleocytosis (88%), and elevated glucose (113) and protein (314). The patient’s mental status returned to baseline prior to discharge, and 1 week later the CSF West Nile Virus IgM returned positive.
Discussion: This case is important for the general hospitalist from both a clinical and quality-improvement perspective. Clinically, this case demonstrates a rare case of West Nile Virus (WNV) encephalitis in an inner-city hospital. Our patient is also younger than most patients that develop neuroinvasive disease, though men and diabetics are at higher risk (1). WNV, an arbovirus of the Flaviviridae family, was first diagnosed in the USA in 1999 during a NYC epidemic, and has since remained at relatively stable, albeit low, levels annually (2,3). Spreading through mosquito vectors, cases in the USA generally present in wooded rural or suburban areas – though recent studies suggest that rising temperatures due to climate change will lead to increased WNV disease incidence in most regions across the country (4). Indeed, surveillance data for 2024 has shown already-increasing rates of WNV detection in boroughs across NYC compared to 2023 (3). Neuroinvasive disease, estimated at less than 1% of all WNV cases, can present with encephalitis, meningitis, and/or flaccid paralysis and can result in severe neurological sequelae including increased intracranial pressure, seizures, and death (5). WNV is treated supportively, though corticosteroids and IVIG have been used in certain severe cases. This case highlights the need to consider WNV neuroinvasive disease in patients presenting with encephalitis even if epidemiologic risk factors, such as advanced age and immunocompromised state, are not present. From a quality-improvement perspective, there was an opportunity to have made the diagnosis earlier. The patient did not undergo an LP until 7 days after his presentation due to the need for neuro IR assistance. An earlier LP would have led to earlier diagnosis, improved antibiotic stewardship, and more timely coordination of his outpatient care management.
Conclusions: This case provides both clinical and systems-related relevance to the hospitalist, as it: i) describes the importance of considering WNV as a differential diagnosis even in an unexpected host or geographic setting, and ii) demonstrates the impact that systems-level factors may have on delays in diagnosis and treatment.