A sequential study of Chikungunya fever cases notified in the urban setup of India

Context: Chikungunya's resurgence highlights reporting and awareness challenges.

Aims: To analyze trends in 170 laboratory-confirmed Chikungunya cases in Urban Surat's Central Sentinel Surveillance (2016-2020), supplemented by a subset (n = 30) examining perceptions, attitudes, and risk reduction practices based on notification level.

Results: Notification rates peaked in 2017 (1.14 cases/100,000). A high House Index (>1) was observed in 59% (2018) and 58% (2019) of cases. Seasonal peaks occurred in November (31%) and December (24.7%), with no private sector notifications. Highest case rates were in South (9.2) and Southeast (8.1) zones. Over half of the cases in Central (69.2%), Southeast (67.2%), and South (52.8%) zones had a House Index >1 (P = 0.001), indicating significant indoor mosquito breeding. Median age was 37 years (30-43), with females comprising 65.3% of cases. Awareness of mosquitoes as vectors (40%) and their day-biting behavior (26.7%) was low, despite familiarity with Abate larvicide (60%). Prevention methods included mosquito coils (76%) and fumigation (73%), with less emphasis on water change (40%) and container maintenance (23%). Only 13% perceived Chikungunya as preventable, with low readiness for community engagement (13%). Misconceptions included considering chemical fogging sufficient (63%) and neglecting water-logging as a health concern (40%). Few implemented risk reduction measures (23% removing stagnant water, 20% weekly water change).

Conclusion: Fluctuating notifications and unnoticed surges in 2019-2020 underscore the need for continuous, standardized surveillance. Higher case rates in southern and central regions were linked to high indoor breeding. The lack of private sector reporting and underreporting indicate a need for integrated surveillance. Awareness and adoption of Aedes-specific risk reduction practices remain low, with persistent misconceptions and poor attitudes.