The mortality burden of multidrug-resistant pathogens in India: a retrospective observational study

BACKGROUND:

The threat posed by antibiotic resistance is of increasing concern in low- and middle-income countries (LMICs) as their rates of antibiotic use increase. However, an understanding of the burden of resistance is lacking in LMICs, particularly for multi-drug resistant (MDR) pathogens.

METHODS:

We conducted a retrospective, ten hospital study of the relationship between MDR pathogens and mortality in India. Patient-level antimicrobial susceptibility tests (AST) results for Enterococcus spp., Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. were analyzed for their association with patient mortality outcomes.

RESULTS:

We analyzed data on 5,103 AST results from 10 hospitals. The overall mortality rate of patients was 13.1% (n = 581), and there was a significant relationship between MDR and mortality. Infections with MDR and XDR E. coli, XDR K. pneumoniae, and MDR A. baumannii were associated with 2-3 times higher mortality. Mortality due to methicillin-resistant S. aureus (MRSA) was significantly higher than susceptible strains when the MRSA isolate was resistant to aminoglycosides.

CONCLUSIONS:

This is one of the largest studies undertaken in an LMIC to measure the burden of antibiotic resistance. We found that MDR bacterial infections pose a significant risk to patients. While consistent with prior studies, the variation in drug resistance and associated mortality outcomes by pathogen is different from that observed in high-income countries and provides a baseline for studies in other LMICs. Future research should aim to elucidate the burden of resistance and the differential transmission mechanisms that drive this public health crisis.