Daijiworld Media Network - New Delhi

New Delhi, Apr 12: A large US-based study has found that mortality rates linked to difficult-to-treat resistant (DTR) infections remain largely unchanged, despite the availability of newer antibiotics—highlighting a critical gap in timely and effective treatment.

DTR infections, particularly those caused by Gram-negative bacteria, are resistant to commonly used first-line drugs such as β-lactams and fluoroquinolones. These infections are associated with significantly higher mortality—around 40% more—compared to infections that respond to standard treatments.

Study Insights and Scope

The research examined over 8 million hospital cases between 2016 and 2023, identifying more than 5,000 patients with confirmed DTR Gram-negative infections. Key pathogens included Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter baumannii.

Although newer antibiotics designed to target these resistant organisms have become more widely available, their real-world effectiveness in improving survival outcomes appears limited.

Underuse of Targeted Treatments

One of the study’s most concerning findings is the continued mismatch between prescribed antibiotics and the actual susceptibility of the infecting bacteria. While the use of newer, DTR-specific antibiotics increased from 4% in 2016 to 15% in 2023, a vast majority of patients—84% even in recent years—still received initial treatments that were ineffective against their infections.

This issue, known as in-vitro discordant therapy, can delay appropriate care and significantly worsen patient outcomes.

Mortality Trends Remain Stagnant

After accounting for variables such as patient demographics, hospital factors, and the impact of the pandemic, researchers found no substantial improvement in mortality rates for most infections caused by these resistant bacteria.

A slight exception was observed in bloodstream infections linked to Pseudomonas aeruginosa, where a modest decline in deaths was noted. However, experts caution that this finding is based on limited data and should be interpreted carefully.

What Needs to Change

The study underscores that simply developing new antibiotics is not enough. Faster and more accurate diagnostic tools are essential to identify both the pathogen and its resistance profile early, enabling doctors to prescribe the right treatment without delay.

Experts emphasize the importance of stronger antimicrobial stewardship practices and improved diagnostic turnaround times. Without these, mortality rates from DTR infections are unlikely to decline, even as new drugs continue to enter the market.