ABSTRACT
Chikungunya virus (CHIKV) and Japanese encephalitis virus (JEV) are mosquito-borne diseases the incidence of which is rising and affecting new populations. CHIKV is prevalent in parts of Asia and Africa and has emerged in South America. While it manifests primarily as an arthralgia, mild neurological symptoms often accompany the syndrome. Severe neurological symptoms are uncommon but can cause long-term morbidity particularly in adults. This includes, encephalitis, acute disseminated encephalomyelitis, brainstem encephalitis, myeloradiculopathy, and Guillain–Barre syndrome. Vertical transmission causing an encephalitis in neonates may also occur. A vaccine for CHIKV is currently in clinical trials. Despite an effective vaccine for JEV, it remains prevalent in East and South East Asia. The virus invades the basal ganglia and the brainstem and can thus present with an encephalitis with a wide variety of movement disorders or severe brainstem dysfunction. In some, it can infect the anterior horn cells causing an acute flaccid paralysis. Diagnosis is dependent on antibody testing, and there is no specific antiviral therapy for CHIKV or JEV. Hence, management includes supportive measures.
