Atypical presentation of a neuroinvasive west nile fever

ABSTRACT

Background West Nile Virus is the most common cause of arboviral diseases and is endemic in the US. It can cause clinical presentation ranging from asymptomatic infection to neuroinvasive disease. Factors like old age, hematologic malignancies, and organ transplantation result in more severe disease. Case presentation An 85-year-old male farmer with coronary artery disease, congestive heart failure (CHF) and diabetes presented with sore throat, cough and shortness of breath. He was treated for CHF exacerbation and discharged but returned with fatigue, headache, Nausea, and vomiting. Imaging of the head and chest, inflammatory markers, COVID-19 PCR,and metabolic panel were all negative, . Then he became febrile, lethargic, and had altered mentation. He exhibited asymmetric weakness, bilateral positive Babinski and neck rigidity. Intravenous ceftriaxone, vancomycin, bactrim, and acyclovir were all initiated for meningoencephalitis of unclear etiology. CSF analysis showed 51 WBC, 0 RBC, 49% granulocytes, 55 glucose and 74 proteins. He was transferred to ICU with a glasgow coma score of 6-7 but was on a 'DO NOT INTUBATE' status. He developed acute anuric kidney injury which prompted emergent hemodialysis and vasopressor support had to be initiated. Family elected for palliative care, and he passed away shortly after. A day later, West Nile serology was reported positive as IGM in CSF. Also, both IgG and IgM were positive in serum Discussion This case demonstrates a rare, severe presentation of West Nile infection. Most persons infected with West Nile (WNV) virus are asymptomatic;symptoms are seen in only about 20 to 40 percent of infected patients [1] Serologic surveys and extrapolations from blood donor screening data indicate that neuroinvasive disease following infection is infrequent, with estimates ranging from 1 in 140 to 1 in 256 infections resulting in meningitis or encephalitis [2] The patient's risk factors for severe infection include elderly age and male sex. Age in particular is the most important risk factor for neurologic progression of disease.[3] The diagnosis can be suspected in patients who have altered mental status, signs of meningitis, unexplained fever, and focal neurologic deficit, especially when it presents in late summer months and has no obvious etiology. The CSF West Nile IgM antibody detection via ELISA is diagnostic as was in our case. The treatment is mainly supportive. The preventive measures including mosquito control, personal protective devices are of substantial importance. Vaccines are not available. [4 5 6] Conclusion The high index of suspicion is necessary to diagnose WNV neuroinvasive diseases especially in patients with atypical presentation. Seasonal clues must be considered.