Bronchiectasis patients’ risk of developing antibiotic-resistant bacteria increases if they have a chronic kidney disease, have been hospitalized in the past year, or have had previous multidrug-resistant infections, a study reports.
The findings could help doctors identify patients at higher risk of developing hard-to-treat infections, and recommend preventive measures.
Researchers published their study, “Risk factors for multidrug-resistant pathogens in bronchiectasis exacerbations,” in the journal BMC Infectious Diseases.
Non-cystic fibrosis bronchiectasis, or BE, is a chronic lung condition whose hallmarks include frequent flare-ups and recurring infections. This leads to patients often receiving rounds of broad-spectrum antibiotics, increasing their chance of acquiring antibiotic-resistant bacteria.
“The incidence and spread of MDR [multidrug-resistant] microorganisms among BE patients is worrisome because the antibiotic arsenal is scarce,” the researchers wrote.
They decided to identify factors that could increase the risk of BE patients developing multidrug-resistant infections, and assess the infections’ impact on patients’ outcomes.
Researchers reviewed the records of patients taking part in a bronchiectasis study between 2011-2015 at two hospitals. Patients were enrolled in the study at their first flare-up, which required either a new antibiotic or a hospital admission.
The study covered 233 patients who had had one flare-up, or exacerbation. The researchers who reviewed the records identified the microorganisms involved in the flare-ups in 159 of the patients.
A key finding was that 20 percent of the flare-ups involved multidrug-resistant bacteria.
The main multidrug-resistant bacteria, Pseudomonas aeruginosa, occurred in 49 percent of cases. Eighteen percent of patients had methicillin-resistant Staphylococcus aureus, and 6 percent had extended spectrum betalactamase + Enterobacteriaceae.
More than twice as many patients who required hospitalization had antibiotic-resistant bacteria than those who were not hospitalized – 25 percent versus 10 percent.
Studying the medical records carefully led to researchers identifying three risk factors for patients acquiring multidrug-resistant bacteria: chronic kidney disease, hospitalization in the previous year, and previous infections of multidrug-resistant bacteria.
The presence of more than one factor led to exponential increases in patients’ risk of developing an antibiotic-resistant bacteria. When none of the factors was at play, only 4 percent of patients were at risk of developing resistant bacteria. The figure was 13 percent when one factor was at play, and 54 percent when either two or three factors were involved.
“Hospitalization in the previous year, chronic renal [kidney] disease, and prior multidrug-resistant isolation are risk factors for identification of multidrug-resistant pathogens in exacerbations,” the team wrote. This information could help doctors choose antibiotics for BE patients, they wrote.