Ethical reporting and oversight in outbreak investigations conducted in India, 2015-2025: a systematic review

Outbreak investigations generate actionable evidence to identify sources of infection and guide effective control measures. In outbreak settings, ethical considerations become even more significant because such investigations often involve vulnerable populations, the collection of identifiable data, and interventions under conditions of uncertainty. The Indian Council of Medical Research states that while there may be a need to undertake research quickly, this should not compromise scientific validity or the need to uphold ethical requirements. However, the extent to which outbreak investigations in India comply with ethics oversight reporting has not been systematically examined. The objective was to evaluate ethical considerations in outbreak investigations conducted in India, published between 2015 and 2025 that reported ethical statements, obtained ethical approval, and participant informed consent.

The review was registered in PROSPERO 2025 CRD420251140176. Human outbreak investigations conducted in India, published from 1 January 2015 to 25 August 2025, were searched in databases viz., Embase, PubMed, Scopus, and Web of Science. Analysis was conducted using R software.

A total of 76 outbreak investigations were included. Overall, 14 (18%) did not report an ethics statement, while 31 (41%) reported an ethics statement without Institutional Ethics Committee approval, and 31 (41%) reported both an ethics statement and approval. Participant consent was not obtained in 41 (54%) publications, written consent was obtained in 26 (34%), and 9 (12%) reported verbal consent. Investigations published in later years demonstrated significantly higher levels of ethics oversight (p < 0.001), and ethics oversight varied significantly across disease groups (p = 0.04); no association was observed with study setting or methodological completeness.

Ethics reporting in outbreak investigations in India remains inconsistent. Routine ethics preparedness requires IEC readiness for rapid review and integration with outbreak investigation initiation.

Less than half documented formal Institutional Ethics Committee approval. The findings highlight the need to strengthen ethical preparedness within outbreak response systems. Strengthening ethical preparedness through rapid review mechanisms, integration of ethics oversight within IDSP-linked investigations, standardised reporting practices, and capacity building of field investigators may help ensure a more ethically robust and transparent outbreak response system.