Daijiworld Media Network – New Delhi

New Delhi, Sep 1: A major study by the Indian Council of Medical Research (ICMR) has found that hospitalised patients suffering from infections caused by antibiotic-resistant gram-negative bacteria face a higher risk of death and significantly higher treatment costs.

The study, conducted across 20 tertiary-care hospitals between April 2022 and April 2025, analysed data from 159,336 hospitalised patients. Of these, 26,213 had confirmed gram-negative bacterial infections, with 61.1% involving bacteria resistant to carbapenem antibiotics.

Researchers examined four major pathogens — Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa — and compared outcomes between carbapenem-resistant and drug-susceptible infections.

Mortality was consistently higher among patients with resistant infections. Deaths were recorded in 24.4% of resistant E. coli cases compared with 17.3% of susceptible cases. For K. pneumoniae, mortality stood at 31.2% in resistant infections against 23.5% in susceptible infections.

Similarly, mortality among patients with resistant A. baumannii infections was 37.9%, compared with 32.8% for susceptible infections. For P. aeruginosa, the figures were 28.9% and 20.2%, respectively.

The risk was particularly severe when the infection entered the bloodstream. Mortality among patients with carbapenem-resistant bloodstream infections ranged from 39.3% for E. coli to 50.8% for A. baumannii.

The study also found that resistant infections were more expensive to treat. Average antibiotic costs were nearly Rs 39,846 for resistant E. coli infections, compared with Rs 20,034 for susceptible infections. Treatment costs for resistant A. baumannii and P. aeruginosa infections were also substantially higher.

Overall, antibiotic treatment costs for carbapenem-resistant infections were around 1.1 to two times higher than those for susceptible infections. The researchers noted that these figures cover only antibiotic costs and exclude hospitalisation, diagnostics, doctors' fees and supportive care, meaning the actual financial burden could be considerably higher.

A large majority of the infections were healthcare-associated, with more than 85% of infections involving each of the four bacteria linked to healthcare settings. Recent surgery and the use of medical devices were also more common among patients with resistant infections.

The researchers stressed the need for stronger infection prevention and control measures, faster diagnostics and responsible use of antibiotics. They also called for improved access to effective treatments and stronger antimicrobial stewardship to tackle the growing threat of antibiotic resistance.

The authors cautioned that the study was conducted largely in tertiary hospitals that handle referred and critically ill patients. Therefore, the mortality figures should not be interpreted as indicators of hospital performance.