Antimicrobial resistance and insecticide resistance co-occurrence in synanthropic flies and their implications for military health in large-scale combat operations

Disease and non-battle injuries (DNBI) continue to cause more casualties among military personnel than combat-related injuries during armed conflict. Modern US Force Health Protection programmes have successfully reduced DNBI and infectious disease rates through comprehensive preventive measures. However, the anticipated return to large-scale combat operations (LSCO), which are characterised by high troop concentrations, degraded sanitation and intense operational tempo, will create conditions favourable for vector proliferation and subsequent pathogen transmission. Emerging evidence underscores a dual biological threat: antimicrobial-resistant (AMR) pathogens and insecticide-resistant (IR) synanthropic flies capable of harbouring and transmitting these organisms. This manuscript examines the historical context of DNBI control, the rise of AMR and IR as intersecting threats, and case examples from Iraq and Taiwan illustrating operational challenges. We propose an integrated surveillance and response framework to address AMR-IR convergence that will help protect deployed forces in future LSCO environments.