A comprehensive three-year study conducted by the Indian Council of Medical Research (ICMR) has provided a stark assessment of the clinical and economic impact of antimicrobial resistance (AMR) in India. Analyzing data from 159,336 hospitalized patients across 20 tertiary-care hospitals between April 2022 and April 2025, the research highlights that infections resistant to carbapenem antibiotics—a critical last-resort treatment—are significantly driving up both patient mortality and healthcare costs.
The findings, published in the October 2026 issue of The Lancet Regional Health – Southeast Asia, underscore the severity of the crisis. Among the 26,213 patients identified with Gram-negative bacterial infections, more than 60% exhibited resistance to carbapenem drugs. This resistance is not merely a laboratory observation but a direct contributor to adverse patient outcomes, particularly in cases of bloodstream infections where mortality rates for resistant strains reached as high as 51%.
Clinical Impact of Carbapenem Resistance
The study, led by Dr. Kamini Walia, head of the ICMR’s Descriptive Research Division, demonstrates a clear correlation between drug resistance and increased risk of death. Patients infected with carbapenem-resistant strains of E. coli and P. aeruginosa faced a 41% and 43% higher relative risk of mortality, respectively, compared to those with susceptible infections. For K. pneumoniae, the relative risk was 33% higher, while A. baumannii showed a 16% increase.
Absolute mortality figures further illustrate the danger. For instance, mortality for carbapenem-resistant E. coli stood at 24.4%, compared to 17.3% for susceptible strains. The most alarming outcomes were observed in bloodstream infections caused by non-fermenting bacteria like A. baumannii and P. aeruginosa, where mortality rates ranged from 46% to 51%. These infections often progress rapidly to sepsis and multi-organ failure, leaving clinicians with limited therapeutic windows.
Economic and Hospitalization Burdens
Beyond the human toll, the study quantifies the financial penalty of AMR. Treatment costs for drug-resistant infections were found to be 1.1 to 2 times higher than those for susceptible infections. This is largely due to the necessity of using more expensive, newer-generation antibiotics and combinations of drugs once first-line treatments fail. Patients with resistant infections also frequently require longer hospital stays and more intensive monitoring.
However, the relationship between resistance and length of stay is complex. While patients with resistant E. coli stayed an average of 23 days compared to 18 days for those with susceptible strains, the study noted a paradox for A. baumannii and P. aeruginosa. In these cases, shorter hospital stays were sometimes observed, which researchers attribute to early mortality among patients with highly resistant, difficult-to-treat infections.
Healthcare-Associated Infection Patterns
A significant portion of the infections studied were classified as healthcare-associated, meaning they were acquired within the hospital environment. The data showed that 85% of E. coli infections, 91.6% of K. pneumoniae, 95.1% of A. baumannii, and 91.9% of P. aeruginosa infections were healthcare-associated. These figures suggest that the battle against AMR must extend beyond antibiotic stewardship to include rigorous infection prevention and control measures.
Dr. Kamini Walia emphasized the necessity of integrated surveillance that links AMR data directly to patient outcomes. “For India, the study highlights the need to move beyond drug resistance surveillance to integrated surveillance linking AMR with patient outcomes, while strengthening infection prevention, right and timely diagnostics, antimicrobial stewardship and access to effective newer antibiotics,” she stated. The study authors noted that while the participating hospitals maintain high standards of infection control, the findings likely reflect the reality of managing critically ill patients in tertiary-care settings.
Future Directions for AMR Management
The researchers advocate for a multi-pronged approach to mitigate the impact of AMR. This includes improving access to affordable, effective novel antimicrobials and ensuring that diagnostic testing is both timely and accurate. By identifying resistant organisms early, clinicians can better tailor treatments, potentially reducing the reliance on broad-spectrum antibiotics that contribute to further resistance.
ICMR researcher Dr. Sonam Vijay highlighted the urgency of these interventions, noting that the findings “highlight the need for timely diagnostics and access to effective, affordable novel antimicrobials to improve outcomes and reduce the economic burden of carbapenem-resistant infections.” As the evolutionary contest between bacteria and antibiotics continues, the study serves as a critical reminder that preventing the spread of infections within healthcare facilities is as vital as the development of new therapeutic agents.
