Antibiotic Resistance and the Return to a Pre-Antibiotic Era: A Critical Narrative Review of a Global Catastrophe.

Antimicrobial resistance is a growing global crisis that threatens to return humanity to a pre-antibiotic era where common infections become deadly. This narrative review synthesizes evidence from 2000 to early 2026, including Global Research on Antimicrobial Resistance data and World Health Organization surveillance, to outline the problem's scale, drivers, and solutions. In 2019, bacterial resistance directly caused 1.27 million deaths and was linked to 4.95 million more. Low- and middle-income countries bear the heaviest burden. ESKAPE pathogens, especially carbapenem-resistant Acinetobacter baumannii and NDM-producing Klebsiella pneumoniae, drive intensive care unit mortality near 50% and cause untreatable neonatal sepsis. One Health drivers include antibiotic overuse in humans, with 30% of prescriptions unnecessary in high-income settings; agriculture, consuming 70% of global antibiotics; and environmental pollution, with resistance genes found in 72% of rivers. Bacteria spread resistance through horizontal gene transfer and mutations such as gyrA S83L, creating pan-drug-resistant strains that make surgeries, transplants, and cancer treatment risky. Economic modeling studies suggest that unchecked antimicrobial resistance could reduce annual global GDP by 1.1-3.8%, with some scenarios projecting losses of up to approximately 5% by 2050, depending on assumptions about healthcare costs, labor productivity, and livestock production. Solutions require subscription-based payment models, enforceable agricultural regulations, integrated genomic surveillance, and equity-focused diagnostics for low- and middle-income countries. Without binding 2030 targets, the post-antibiotic era would become a clinical reality within a decade.