Chandipura Virus in India: A Systematic Review of Public Health Challenges, Evidence Gaps, and Future Priorities

Background: Chandipura virus (CHPV) is a re-emerging viral pathogen causing acute encephalitis syndrome (AES) in India, with reported case fatality rates of 33-70% primarily among children. Transmitted by sandflies and mosquitoes, CHPV remains inadequately studied despite recurrent outbreaks. This systematic review critically examines the literature on CHPV in India to identify public health challenges, assess evidence quality, and propose targeted interventions. Methods: We systematically searched PubMed, Scopus, Web of Science, and Google Scholar (inception to January 2025) following PRISMA 2020 guidelines. Two reviewers independently screened, extracted data, and assessed study quality using JBI and AMSTAR 2 tools. Narrative synthesis was employed. Results: Of 1,590 identified records, 25 studies met the inclusion criteria. Quality assessment revealed only 36% (n=9) were high-quality studies, predominantly outbreak investigations. Thematic analysis identified twelve interconnected challenges, with four critical gaps consistently reported across high-quality studies: (1) inadequate surveillance infrastructure delaying outbreak detection (documented in 8 states), (2) diagnostic limitations leading to misclassification with Japanese encephalitis and dengue, (3) absence of specific antiviral therapy or vaccine, and (4) evolving vector ecology with species shift from Phlebotomus to Sergentomyia sandflies. Pooled case fatality rates from four high-quality outbreak investigations ranged from 43.6-78.3%. The 2024 Gujarat outbreak (64 confirmed cases, 33% CFR) underscores persistent vulnerability. Conclusion: CHPV poses a significant but evidence-poor public health threat in India. Current knowledge relies heavily on low-quality descriptive studies. Strengthening rural healthcare infrastructure, integrating CHPV surveillance into existing vector-borne disease programs, and prioritizing high-quality prospective research are urgently needed.