Tick borne encephalitis without cerebrospinal fluid pleocytosis

Abstract

BackgroundTick borne encephalitis is the most frequent vector-transmitted infectious disease of the central nervous system in Europe and Asia. The disease caused by European subtype of tick borne encephalitis virus has typically a biphasic clinical course with the second phase presenting as meningitis, meningoencephalitis, or meningoencephalomyelitis. Cerebrospinal fluid pleocytosis is considered a condition sine qua non for the diagnosis of neurologic involvement in tick borne encephalitis, which in routine clinical practice is confirmed by demonstration of serum IgM and IgG antibodies to tick borne encephalitis virus.Case presentationHere we present a patient from Slovenia, an area highly endemic for tick borne encephalitis, with encephalitis but without cerebrospinal fluid pleocytosis in whom tick borne encephalitis virus infection of the central nervous system was demonstrated.ConclusionCerebrospinal fluid pleocytosis is not mandatory in encephalitis caused by tick borne encephalitis virus. In daily clinical practice, in patients with neurologic symptoms/signs compatible with tick borne encephalitis and the risk of exposure to ticks in a tick borne encephalitis endemic region, the search for central nervous system infection with tick borne encephalitis virus is warranted despite the lack of cerebrospinal fluid pleocytosis.

Clinical Presentation and Laboratory Diagnostic Work-Up of a Horse with Tick-Borne Encephalitis in Switzerland

“…CSF analysis usually reveals pleocytosis [2], although there are reports of human patients with TBE without pleocytosis [39,40]. Accordingly, the absence of pleocytosis (as in our patient, which only showed elevated protein in CSF) does not rule-out TBE.…”

EAN consensus review on prevention, diagnosis and management of tick‐borne encephalitis

“…For TBE, moderately raised CSF protein and mononuclear pleocytosis ranging from 6 × 10 6 to 1200 × 10 6 cells/l but normal glucose and lactate levels are characteristic . Exceptionally, TBE has been demonstrated without CSF pleocytosis . Early after the disease onset, TBEV‐specific antibodies can be found in the CSF in half the patients, but they are detectable in almost all patients within 10 days .…”

Before blaming SARS-CoV-2 for venous sinus thrombosis in a septic patient, consider alternative etiologies

“…Because the patient was lethargic, restless, and sleepy, results of multimodal cerebral MRI with contrast medium are mandatory to rule out encephalitis, ventriculitis, and stroke. Encephalitis may be present even in the absence of pleocytosis [4] and the only abnormal CSF finding may be elevated CSF protein, as in the index patient [1] .…”