Objective:

This study aims to access the early, late-onset and long-term neurological outcomes of Nipah virus infection among individuals in the affected countries.

Background:

Nipah virus (NiV) is an emerging zoonotic RNA virus from the paramyxovirus family causing severe respiratory and acute febrile encephalitic illness in humans. The virus first emerged in Malaysia and Singapore in 1998/1999 and subsequently from 2001 in Bangladesh and West Bengal, India till 2023 in Kerala, India. Pteropus fruit bats serve as reservoirs for the virus which leads to human spread via the consumption of food contaminated with bats secretion, contact with infected animals and human-to-human spread.

Design/Methods:

We examined 1,055 articles from existing literature in PubMed, Medline and Google Scholar databases and screened 79 relevant articles investigating the neurological outcomes associated with Nipah virus infection using a predefined inclusion and exclusion criteria.

Results:

NiV infection in humans produces an encephalitic syndrome ranging from headache and pyrexia to brain stem abnormalities, reduced or absent reflexes and doll’s eye reflex; reduced level of consciousness (55% in Malaysia, 90% in Bangladesh) including tonic-clonic convulsions and segmental myoclonus. Fever with altered sensorium was the most common presentation in Siliguri, India (97%) and Bangladesh (90%), with a case fatality ratio (CFR) of about 40-100% in recent outbreaks. Relapse or residual neurological deficits were seen in 10-15% of survivors an average of 8 months after primary encephalitis. Brain MRI showed small discrete hyperintense lesions, widespread in the cortex, subcortical and deep white matter from microinfarctions due to underlying vasculitis of the cerebral blood vessels, seen in acute infections and patchy confluent hyperintense cortical lesions seen in relapsing NiV infections.

Conclusions:

Proper education on good hygiene is important to prevent the re-emergence of the viral infection in affected areas. Effective neurorehabilitation is also necessary to reduce the long-term neurological complications in NiV survivors.