Clinical Report: First Neuroinvasive Oropouche Virus Case in Wisconsin, USA
Overview
This report documents the first neuroinvasive Oropouche virus (OROV) case in Wisconsin and the United States, linked to travel in Panama. The patient presented with biphasic meningitis symptoms, and diagnosis was confirmed after extensive testing including CDC confirmation.
Background
Oropouche virus is a reemerging arbovirus endemic to parts of South America and the Caribbean, with no vaccine or specific treatment available. Environmental changes and international travel have contributed to its spread, raising concerns about new geographic areas of infection. Neuroinvasive disease manifestations, although rare, require heightened clinical awareness, especially in travelers returning from endemic regions.
Data Highlights
Parameter
Value
White Blood Cell Count
11.8 × 10³/μL (mild leukocytosis)
CSF Nucleated Cell Count
72/μL (97% lymphocytes)
CSF Glucose
51 mg/dL (normal)
CSF Protein
58 mg/dL (elevated)
CSF Lactate
1.9 mmol/L (normal)
Blood CHIKV IgM
Positive
Other Viral PCRs (CHIKV, Dengue, Zika)
Negative
Meningitis/Encephalitis PCR Panel
Negative
Key Findings
First documented neuroinvasive OROV case in Wisconsin and the United States in 2025.
Patient presented with biphasic meningitis symptoms including headache, neck stiffness, blurry vision, dizziness, and unsteadiness.
Initial positive chikungunya virus IgM antibody complicated diagnosis; extensive testing ruled out other arboviruses and common meningitis pathogens.
CSF analysis showed lymphocytic pleocytosis and elevated protein consistent with viral meningitis.
Travel history to rural Darién Province, Panama, with mosquito exposure was critical for suspicion of OROV infection.
Diagnosis confirmed by CDC testing after referral from state laboratory.
Clinical Implications
Clinicians should consider Oropouche virus infection in patients presenting with aseptic meningitis symptoms and relevant travel history to endemic regions, especially given the absence of specific treatments. Awareness of biphasic symptom patterns and the potential for neuroinvasive disease is important for timely diagnosis and management. Comprehensive arboviral testing including referral to specialized laboratories may be necessary for confirmation.
Conclusion
This case highlights the emergence of Oropouche virus in new geographic areas facilitated by travel and environmental factors, underscoring the need for vigilance in diagnosis of neuroinvasive arboviral infections in the United States.
References
Pan American Health Organization/World Health Organization 2024 -- Oropouche Virus Reemergence and Spread
Centers for Disease Control and Prevention 2025 -- Arboviral Diseases Branch Confirmation Testing
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