Case Presentation: A 71-year-old male with no known past medical history presented with chief complaint of fatigue associated with generalized weakness, malaise, slurring of speech and body aches specifically upper and lower back pain for 3 weeks. He reported working in the woods. Vital signs were unremarkable. Physical exam was remarkable for a faint erythematous periumbilical rash but did not have any focal neurological deficits. Labs were remarkable for leukocytosis of 18000/µL , elevated ESR 56 mm/hr, and CRP 6.43 mg/dL. Other labs including BMP, UA, and CPK, Rheumatoid factor, ANA screen, Anti-dsDNA, and ANCA were unremarkable. Blood and urine cultures were negative. CT head and MRI brain did not reveal any acute intracranial pathology. CT chest and abdomen/pelvis were unremarkable for any infectious foci. CT spine was negative for infectious focus. Given elevated ESR, there was a concern for PMR for which he was trialed on low dose prednisone with minimal improvement. During the hospital stay, the patient developed a right-sided facial palsy involving forehead following which he was initiated on valacyclovir and high dose prednisone. Despite negative antibody screen Lyme disease was strongly suspected there he was also started on Rocephin. Because he was experiencing neurological symptoms of elusive etiology, lumbar puncture was performed. CSF fluid analysis was significant for elevated protein 146 mg/dL. The patient showed clinical improvement and was discharged on ceftriaxone for 4 weeks with some CSF lab results still in-process. Finally, CSF serology resulted as positive for West Nile (WN) Virus IgM 3.13 and IgG 16.20. The patient continued to exhibit progressive improvement on the outpatient follow-up.
Discussion: With this, we report the first case of WN Virus infection in Allegheny County this year. WN virus is a member of the Japanese encephalitis virus antigenic complex and can lead to a wide range of clinical symptoms from asymptomatic disease to severe meningitis and encephalitis. About 25% of those infected with WN virus develop WN fever and 1 out of 150 to 250 develop neuroinvasive disease. WN fever is a self-limited illness and is characterized by an abrupt onset of fever, headache, malaise, back pain, myalgias, and anorexia. 25-50% of patients develop a rash. Facial palsy is a less common manifestation of WN fever noticed in about 13% cases. A lot of these symptoms are nonspecific as they are seen in several viral illnesses. Since it is an arthropod vector-borne condition, it is speculated our patient likely had an exposure to mosquitoes unknowingly while working in the woods.
Conclusions: Hospitalists frequently encounter patients with unexplained constitutional symptoms. CSF evaluation should be considered in these patients with any neurological manifestation, especially in endemic areas like North-east US. Early diagnosis will help limit unnecessary empiric antimicrobials as well as an extensive resource utilization in pursuit for identifying the correct diagnosis.