Neurological complications of Chikungunya virus infection

Background: In May 2006, there was a large Chikungunya virus infection (CHIKV) outbreak in the Nagpur district of Maharashtra, a province in western India. Usually, CHIKV is a self-limiting febrile illness. However, neurological complications have been described infrequently.
Aim: To study the clinical characteristics of various neurological complications associated with CHIKV infections.
Materials and Methods: Patients with neurological complications following CHIKV infection during the outbreak were the subjects of the study. On the basis of clinical features and investigative findings, patients were grouped into various neurological syndromes: Encephalitis, myelopathy, peripheral neuropathy, myeloneuropathy, and myopathy. Cerebrospinal fluid (CSF) samples were also collected for biochemical and serological studies.
Results: Of the 300 patients with CHIKV infection seen during the study period, June-December 2006, 49 (16.3%) [M : F: 42:7] had neurological complications. The neurological complications included: Encephalitis (27, 55%), myelopathy (7, 14% ), peripheral neuropathy (7, 14%), myeloneuropathy (7, 14%), and myopathy (1, 2%). Reverse Transcriptase polymerase chain reaction (RT-PCR) and real-time PCR was positive in the CSF in 16% and 18%, respectively.
Conclusion: Recent CHIKV infection was associated with various neurological complications, suggesting neurotropic nature of the virus. The outcome of the neurological complications is likely to be good.

Keywords
Chikungunya, neurological complications, encephalitis, myelitis, peripheral neuropathy, cerebrospinal fluid