# West Nile Virus–Associated Hemophagocytic Lymphohistiocytosis, Switzerland

## TL;DR

A 62-year-old man in Switzerland developed a severe West Nile virus infection with unusual symptoms, which was diagnosed using advanced sequencing and eye exams.

## Contribution

Reports a rare case of West Nile virus-associated hemophagocytic lymphohistiocytosis and meningoencephalitis in a European patient.

## Key findings

- The patient's condition improved with corticosteroid treatment.
- High-throughput sequencing and ophthalmologic findings confirmed the West Nile virus diagnosis.
- The case highlights an atypical and severe manifestation of the virus.

## Abstract

A 62-year-old patient was hospitalized in Geneva, Switzerland, with an atypical manifestation of West Nile virus infection. Initially, he sought care for febrile diarrhea and vomiting; his condition deteriorated and hemophagocytic lymphohistiocytosis and meningoencephalitis developed. Corticosteroids improved his condition. We used high-throughput sequencing and ophthalmologic findings to diagnose West Nile virus.