Chikungunya encephalitis, a case series from an endemic country

Abstract

Background: The Chikungunya Virus (CHIKV) was introduced into Honduras in 2015. Since then the WHO has reported more than 14,000 suspected cases in the country.

Objective: To describe the clinical, laboratory, neuroimaging, and pathological features of CHIKV encephalitis.

Patients and methods: We evaluated all consecutive cases of CHIKV infection meeting encephalitis criteria at Hospital Escuela Universitario at Tegucigalpa, Honduras, during 2015. Who case definition was used: patient with neurological manifestations meeting clinical criteria (fever >38.5 °C, joint pain); resident/visitor in the last 15 days to an endemic area; laboratory confirmation with IgM/ELISA. Other etiologies were excluded by ancillary studies.

Results: Out of 95 cases with suspected CHIKV infection, 7 (7%) cases with CHIKV encephalitis were identified; mean age was 56 years and four were men. The mean latency from onset of symptoms to diagnosis was 5 five days. Clinical manifestations were: fever/arthralgia, headache/alteration of consciousness and status epilepticus. The EEG demonstrated slow background activity and generalized epileptiform discharges in three patients. Brain MRI showed bilateral white matter hyperintensities and one with focal encephalitis; CSF analysis demonstrated lymphocytic pleocytosis and hyperproteinorrachia. Two patients died. Postmortem brain examination of one patient revealed lymphocytic infiltrates with focal necrosis in hippocampus, frontal lobes and medulla oblongata.

Conclusions: Neurological complications of CHIKV are infrequent, but may be severe. In this case series, the neurological manifestation was encephalitis. Predominant symptoms and signs were fever, behavioral abnormalities, headache and seizures. Because of the potential morbidity and mortality of CHIKV encephalitis, these patients should be admitted to hospital urgently.

Keywords: Chikungunya; Encephalitis; Honduras; Imaging; Pathology.