Epidemiology of Antimicrobial Resistance (AMR): Studying Patterns and Contributing Factors Globally

Abstract

Background: Antimicrobial resistance (AMR) is a growing global health crisis, causing an estimated 4.95 million deaths in 2019, with 1.27 million directly attributed to drug-resistant infections. The prevalence of multidrug-resistant (MDR) pathogens has increased by 32% in the past decade, with the highest burden in low- and middle-income countries. This study analyzes epidemiological trends, key drivers, and statistical patterns of AMR globally.

Methods: A systematic review and meta-analysis were conducted using data from the WHO Global Antimicrobial Surveillance System (GLASS), PubMed, and Scopus. A total of 52 cohort studies and 18 randomized controlled trials (RCTs) published between 2015 and 2024 were included. Heterogeneity was assessed using Cochran’s Q test (p < 0.05), and a random-effects model was applied for statistical pooling.

Results: The global prevalence of MDR infections was 38.2% (95% CI: 34.6%–41.9%), with the highest rates in South Asia (47.5%) and Sub-Saharan Africa (45.8%). Gram-negative bacteria accounted for 63.5% of AMR cases, with Escherichia coli (29.3%) and Klebsiella pneumoniae (22.1%) being the most common pathogens. Carbapenem-resistant Acinetobacter baumannii increased by 51% over the past five years, with a mortality rate of 42% (p = 0.003). The overuse of antibiotics in hospitals accounted for 65% of resistant infections, while agricultural misuse contributed to 29%. Countries with antibiotic stewardship programs reported a 23% reduction in resistance rates over five years (p = 0.012).

Conclusion: The rapid rise in AMR is driven by overuse in healthcare and agriculture, with Gram-negative bacteria being the predominant resistant pathogens. Strengthening antibiotic stewardship, improving infection control, and investing in novel antimicrobial therapies are critical for mitigating AMR’s impact. Urgent global efforts are required to prevent a post-antibiotic era.