Neuroleptospirosis: Aseptic Meningoencephalitis or Invasion into the Central Nervous System?

Leptospirosis is a zoonotic disease of global importance with a mortality of up to 50% among patients requiring intensive care medicine. Meningitis or meningoencephalitis due to leptospires are considered to be an immunologically mediated disease and to occur mainly during the second phase of disease. Herein, we report a patient with severe meningo-encephalitis due to leptospirosis with evidence of direct bacterial invasion into the central nervous system (CNS). A 36-year-old otherwise healthy male farmer, without recent travel history, presented with recurrent fever, peaking >39°C, cough and conjunctivitis 10 days after high-pressure cleaning of a piggery without eye protection. Diagnostic work-up revealed meningoencephalitis due to Leptospira species (spp.). Serology (microscopic agglutination test) yielded elevated antibody titers (1:400) for Leptospira interrogans. Polymerase chain reaction (PCR) and electron micrograph of cerebrospinal fluid (CSF) demonstrated direct invasion of Leptospires into the CSF. Magnetic resonance imaging (MRI) of the brain and spine did not reveal any pathologic findings; electroencephalography (EEG) indicated right-hemispheric slowing. Due to severe abdominal pain, gastroscopy was performed. Histology showed signs of vasculitis. Conventional abdominal angiography demonstrated vasculitis resembling panarteriitis nodosa. Combined antibiotic and steroid therapy lead to clinical improvement. Neuroleptospirosis is an important differential diagnosis of occupational meningoencephalitis in Central Europe. This case supports the hypothesis of direct invasion of leptospires into the CNS.