Difficult-to-treat drug-resistant bacteria are spreading rapidly in Bangladesh’s intensive care units (ICUs), while stronger measures can sharply reduce infections, according to studies by the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b).
It came up with the findings of two new studies on 763 patients at a Dhaka hospital, one of which showed that more than half of those who initially carried none of the bacteria acquired them during hospital care.
The study found alarmingly high death rates among patients who developed infections caused by the bacteria.
The second study showed that stronger infection prevention and control measures can sharply reduce severe infections and deaths, said an icddr,b press release issued yesterday.
One of the studies, published in the journal Microbiology Spectrum, analysed 373 critically ill adults admitted to the ICU of a government tertiary hospital in Dhaka between July 2023 and February 2024.
Gazi Md Salahuddin Mamun, assistant scientist at icddr,b and lead author, said researchers followed ICU patients throughout their stay, using laboratory tests and whole-genome sequencing to track how drug-resistant bacteria spread inside the hospital and how bacteria carried by patients later developed into infections.
“This allowed us to identify links between bacteria carried by patients and those causing subsequent deadly infections,” he said.
The study, funded by the US Centers for Disease Control and Prevention (CDC), focused on four common bacteria responsible for many hospital-acquired infections: Escherichia coli (E. coli), Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa.
Many strains of these bacteria no longer respond to commonly used antibiotics.
Researchers found that nearly half of ICU patients, 48.5 percent, were already carrying these bacteria in their bodies without showing symptoms when they were admitted.
The study found 198 of the patients initially tested negative. More worrying, 105 of them, or 53 percent, later acquired the bacteria during their ICU stay, suggesting widespread transmission inside the hospital.
Carrying the bacteria does not necessarily mean a person is infected.
However, patients who carry them are at greater risk of developing serious illness and can spread the bacteria to others.
Among patients who later developed confirmed infections caused by the drug-resistant bacteria, more than 90 percent died in the ICU.
Researchers said the exceptionally high mortality may reflect the realities of resource-constrained intensive care units, including limited treatment options and the spread of hospital-acquired infections in overcrowded settings.
Genetic analysis also showed that, in some patients, the same strain of bacteria they had been carrying later caused life-threatening infections.
Dr Fahmida Chowdhury, lead of the Antimicrobial Resistance Research Unit at icddr,b and principal investigator of the study, said, “A hospital should be a place of healing, not a place where patients acquire another potentially life-threatening infection while seeking treatment.”
She said strengthening infection prevention and control, improving hospital hygiene and ensuring responsible use of antibiotics were essential to better protect critically ill patients.
The second study found that sustained infection prevention measures produced dramatic improvements.
After seven months of intervention, bloodstream infections fell from 28 to four per 100 admissions — an 86 percent reduction.
Deaths also declined from 26 to four per 100 admissions, suggesting that stronger infection prevention and control measures can significantly reduce infections and save lives even where drug-resistant bacteria are widespread.
An earlier icddr,b study documented widespread colonisation with drug-resistant bacteria in hospitals and communities, including among newborns.
The new studies add new evidence on how these bacteria spread within ICUs and how improved infection prevention can reduce infections and deaths.
Tahmeed Ahmed, executive director of icddr,b, said the findings showed that patients were acquiring dangerous drug-resistant bacteria while receiving hospital care, with devastating consequences.
“At the same time, the studies show that strengthening basic infection prevention and control measures can dramatically reduce infections and deaths,” he said.
He urged hospital authorities and policymakers to treat infection prevention, hospital hygiene, surveillance and responsible antibiotic use as core patient safety priorities in the fight against antimicrobial resistance.