- A 10-year hospital study shows resistant infections jumped sharply during COVID lockdowns.
- Older adults, men, and long-stay patients face the highest risk.
- Findings guide prevention now, but new treatments are still in development.
When the world shut down for COVID-19, something else was changing inside hospital walls — the bugs themselves.
The hidden shift inside hospitals
Imagine checking into a hospital for surgery. You expect doctors to fight your illness. You don’t expect to fight a second infection picked up during your stay.
But for thousands of patients each year, that second battle is real. And new research suggests the COVID-19 years may have made it harder.
Hospital-acquired infections are infections you catch while being treated for something else. Many are caused by “superbugs” — bacteria that no longer respond to common antibiotics. Doctors call them multidrug-resistant organisms, or MDROs.
These infections are a huge global problem. They make hospital stays longer, treatments more expensive, and recoveries less certain. For frail or older patients, they can be deadly.
The frustrating part? Doctors have fewer and fewer drugs that still work against them.
What we used to believe
For years, one superbug ruled most hospitals in this region: a stubborn germ called CRAB (carbapenem-resistant Acinetobacter baumannii). It often spread in intensive care units and on breathing machines.
Doctors built their prevention plans around it. Hand washing, isolation rooms, careful cleaning of ventilators — all aimed mostly at CRAB.
But here’s the twist.
A new 10-year study from a large Chinese hospital shows that a different superbug quietly took over during the pandemic. It’s called CRE (carbapenem-resistant Enterobacteriaceae), and one type — Klebsiella pneumoniae — became the most common resistant bug by 2022.
That changes the playbook.
Think of bacteria like traffic
To picture what happened, think of hospital bacteria like cars on a highway.
Before COVID, CRAB was the heavy truck blocking the fast lane. Hospitals built barriers to slow it down. Then the pandemic hit. Wards filled up. Patients stayed longer. Antibiotic use rose. Cleaning routines shifted.
While everyone watched the trucks, smaller, faster cars — the CRE bacteria — slipped through. They spread, multiplied, and took over the highway.
That’s essentially what the new data shows. The mix of germs changed, even though staff were working harder than ever on infection control.
Inside the study
Researchers reviewed records from 2,669 adult patients with confirmed hospital-acquired infections at a tertiary hospital between 2013 and 2023.
They split the years into three phases: before COVID, during strict lockdowns, and after rules eased. Then they tracked which bugs grew, which patients got sick, and which medical procedures raised the risk.
It’s one of the longest looks yet at how pandemic policies reshaped hospital infections.
The share of infections caused by superbugs jumped from about 37% before the pandemic to more than 56% during strict containment. That’s a big leap in a short time.
Bloodstream infections — among the most dangerous types — also rose, from 24% to 32%. These happen when bacteria reach the blood and can spread throughout the body.
Certain patients faced higher risks. Men, people 60 and older, and anyone in the hospital longer than two weeks were more likely to pick up these tougher infections.
The type of bug also depended on the type of medical device used. Patients on mechanical ventilators (breathing machines) were about twice as likely to get a CRAB infection. Patients with urinary catheters (tubes to drain urine) were more likely to get CRE. And patients with breathing tubes had a much higher risk of another superbug called VRE.
This doesn’t mean these devices are unsafe — they save lives every day. But it shows that different tools carry different risks, and prevention must be matched to each one.
The study took place in China, but its lessons travel. Hospitals around the world saw similar pressures during COVID — overcrowding, staff shortages, heavy antibiotic use, and rapid changes in cleaning routines.
Experts have warned for years that pandemics can quietly fuel antibiotic resistance. This research adds real-world numbers to that warning. It also suggests that the most dangerous bug in your local hospital today may not be the one doctors were trained to fight a few years ago.
That kind of shift matters for choosing the right antibiotics, the right tests, and the right prevention steps.
If you or a loved one needs hospital care, don’t panic — most stays are safe. But it’s fair to ask questions.
You can ask staff how they prevent infections, whether a catheter or breathing tube is still needed, and how soon it can come out. Shorter device use often means lower risk.
If you’re older, recovering from major surgery, or staying more than two weeks, your team may take extra precautions. That’s a good thing.
What this study can’t tell us
This research looked back at one hospital’s records, so it can’t prove cause and effect. Other factors — like changes in who got admitted during COVID — may also explain part of the shift.
It also reflects local patterns. The exact mix of superbugs may differ in other countries or smaller hospitals.
Still, the trend it captures lines up with reports from many parts of the world.
Researchers say the next step is smarter, more targeted prevention — matching infection control to the specific bugs most active in each hospital today.
That means faster lab testing, sharper tracking of which germs are spreading, and tighter rules around devices like ventilators and catheters. New antibiotics for CRE are also in development, but bringing a safe drug to patients takes years of trials and review.
For now, the strongest tools remain the basics: careful hand hygiene, thoughtful antibiotic use, and removing tubes and lines as soon as they’re no longer needed.
