Chikungunya and the nervous system: what we do and do not know.

Area of Science:

• Virology
• Neurology
• Epidemiology

Background:

• Chikungunya virus (CHIKV), an alphavirus transmitted by Aedes mosquitoes, has re-emerged globally.
• Neurological manifestations of CHIKV infection, including meningoencephalopathy, have been documented since the 1960s.
• Despite clinical evidence, CHIKV's neurotropism remains incompletely defined, with conflicting animal study results.

Purpose of the Study:

• To define CHIKV-related neurological diseases in adults and children.
• To investigate the neurotropic potential of CHIKV.
• To address inconsistencies in animal studies regarding CHIKV brain invasion and replication.

Main Methods:

• Review of clinical cases of CHIKV infection.
• Analysis of neurological manifestations in adults and children.
• Evaluation of existing animal studies on CHIKV neurotropism.

Main Results:

• Encephalopathy is the most common neurological manifestation in newborns with mother-to-child CHIKV transmission.
• The ratio of central nervous system (CNS) involvement in CHIKV cases appears comparable to other neurotropic viruses.
• Inconsistencies exist in animal models regarding CHIKV's ability to invade and replicate within the brain parenchyma.

Conclusions:

• CHIKV infection poses a significant risk for neurological complications, particularly in newborns.
• Further investigation is crucial to elucidate the neurotropism of CHIKV.
• Understanding CHIKV neurotropism is vital given its emergence in new areas and observed CNS involvement.