Post-acute sequelae after Nipah virus infection: a systematic review and meta-analysis

Nipah virus was first detected in the 1998-1999 Malaysia outbreak and remains a significant public health concern due to its high epidemic potential and recurrent outbreaks in South Asia. Incidence patterns of post-acute sequelae, characterised by persistence or delayed onset after the acute phase of an infection, are not well documented after infectious disease outbreaks. We aimed to address this knowledge gap.

We conducted a systematic review and meta-analysis on the prevalence, incidence, duration, and characteristics of post-acute sequelae in survivors of Nipah virus infection. We searched PubMed and Web of Science for studies published in English between database inception and Nov 17, 2025. Articles were eligible for inclusion if they were peer-reviewed and reported primary data on post-acute sequelae in survivors of Nipah virus infection. Risk of bias was assessed using Joanna Briggs Institute critical appraisal tools. We conducted random-effects meta-analysis for all outcomes reported in at least two studies, and assessed heterogeneity qualitatively and using the I² statistic. This review was registered with PROSPERO CRD42024616198.

Our search identified 1091 articles after deduplication, of which eight were eligible for inclusion in the systematic review and six in the meta-analysis. Study populations included hospitalised Nipah encephalitis survivors and total survivors of Nipah virus infection in three and five articles, respectively. Only one study included a healthy control group. Three articles were of high, four of moderate and one of low quality. We extracted prevalence for 34 potential neurological, psychiatric or non-specific post-acute sequelae. The pooled prevalence of total residual neurological deficits was 24% (95% CI 9-49; I² = 0%) among total survivors of Nipah infection (3 studies; 80 participants), and 45% (95% CI 11-85; I² = 64%) among the subset of survivors with acute Nipah encephalitis (3 studies; 87 participants). Publication bias could not be meaningfully assessed due to the small number of studies in the meta-analysis. In the single controlled study, total residual neurological deficits, fatigue and daytime somnolence were significantly more prevalent in Nipah infection survivors than household controls. We estimated that 10% (95% CI 4-20; I² = 0%) of Nipah infection survivors experience late-onset or relapsing neurological symptoms after initial recovery (3 studies; 291 participants).

These findings demonstrate a substantial long-term disease burden following Nipah virus infection, which should be accounted for in mathematical modelling studies. However, estimates were based on very limited data mainly from the Malaysia/Singapore outbreak. Additional limitations relate to subjective outcome assessment and heterogeneous populations of total Nipah infection survivors, which could have biased our estimates or affected their generalisability. Further research is needed in the Bangladeshi and Indian setting, where current outbreaks occur and are caused by a different viral strain.

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