Prevalence of the Chikungunya during outbreaks in Asia: A systematic review

Tóm tắt

Background: Chikungunya virus (CHIKV) is a re-emerging mosquito-borne alphavirus that has caused recurrent outbreaks across Asia in the 21st century. Outbreak investigations are critical for quantifying burden, characterizing affected populations, and identifying drivers of transmission. This systematic review synthesizes available outbreak-level, laboratory-confirmed evidence from Asia to estimate the proportion of tested individuals who were confirmed as chikungunya during outbreaks, and to summarize reported epidemiological factors associated with outbreak magnitude and severity. Methods: We performed a systematic search of PubMed, Scopus, Embase, and Web of Science for outbreak investigations and surveillance reports conducted in Asia between January 2000 and June 2025 that reported laboratory-confirmed chikungunya counts (numerator and denominator) using RT-PCR or IgM assays. Only outbreak investigations with explicit numerators and denominators and laboratory confirmation were included in the primary analysis. We extracted study-level data including country, year, diagnostic method, number tested, and number laboratory-confirmed. Proportions were logit-transformed and pooled using a DerSimonian–Laird random-effects model. Heterogeneity was assessed with Cochran's Q and I². Forest and funnel plots were generated. Results: Four outbreak investigations meeting inclusion criteria were included from Bangladesh (Dhaka, 2017), Thailand (2018–2019), India (Nagpur, 2006), and Sri Lanka (Kandy, 2006–2007), comprising a total of 3,312 individuals tested and 2,298 laboratory-confirmed cases. The pooled proportion of laboratory-confirmed chikungunya among tested individuals across outbreak investigations was 61.14% (95% CI: 52.35%–69.25%). Heterogeneity was substantial (Q = 46.86, df = 3, tau² = 0.1126, I² = 93.6%). Conclusion: In outbreak settings across Asia, a high proportion of tested individuals were laboratory-confirmed as chikungunya, underscoring the substantial burden during epidemic periods. However, high heterogeneity between investigations cautions against overinterpretation of pooled estimates. Strengthened laboratory surveillance, harmonized case definitions, and integrated vector control remain priorities to mitigate chikungunya transmission in Asia.