The Question: In this study, we examined the association between multidrug-resistant (MDR) and extensively drug-resistant (XDR) bacterial infections and in-hospital mortality outcomes among over 4,000 patients hospitalized in one of ten tertiary or quaternary facilities across India in 2015. This is one of the largest studies to measure the burden of antibiotic resistance in a low- or middle-income country. Our research findings were published in the journal Clinical Infectious Diseases.

What We Found: We found that in-hospital mortality was significantly higher among patients infected with MDR or XDR pathogens including Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii.

The overall mortality rate among all study participants was 13.1 percent, with mortality as high as 29.0 percent among patients infected with A. baumannii. Patients who died were more likely to have been older and admitted to the intensive care unit (ICU) at the time of testing.

We also found that among MDR infections, those caused by Gram-negative bacteria were associated with higher mortality rates compared to those caused by Gram-positive bacteria, with rates of 17.7 percent and 10.8 percent, respectively.

Our study results indicate that patients who acquired MDR bacterial infections were 1.57 times more likely to die, compared to patients with similar susceptible infections, while patients who acquired XDR infections were 2.65 times more likely to die when accounting for age, sex, site of infection, and the number of coinfections.

In both the ICU and non-ICU, the odds of mortality were higher among patients with XDR infections; this association was driven by Gram-negative infections (e.g., XDR K. pneumoniae) highlighting the importance of rapidly identifying these infections among all patients.

Why It Matters: In India, MDR and XDR Gram-negative bacterial infections are frequent, and the availability of effective antibiotic therapies are declining. This study provides greater insight into the urgent need to increase surveillance, research, and antimicrobial stewardship efforts worldwide. Our findings on the mortality burden of antibiotic resistance can aid in the development of policy efforts to prioritize antibiotic resistance as a global public health threat and to inform future efforts to quantify and track the burden of resistance across low- and middle-income countries.

Photo: Scanning electron micrograph of Staphylococcus aureus bacteria. From NIAID on Flickr.