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Infections caused by drug-resistant ‘nightmare bacteria’ are spreading across the US, with the CDC warning of mounting health risks
Infections caused by drug-resistant “nightmare bacteria” have surged nearly 70 per cent between 2019 and 2023.(Representative image)
A new study by scientists at the US Centres for Disease Control and Prevention (CDC), published in the Annals of Internal Medicine, has found that infections caused by drug-resistant “nightmare bacteria” have surged nearly 70 per cent between 2019 and 2023. These bacteria are resistant to carbapenems, antibiotics usually reserved as a last line of defence, making them extremely difficult and costly to treat.
Researchers noted that bacteria carrying the New Delhi metallo-β-lactamase (NDM) gene are the main driver of this surge. In 2023, 29 US states that conduct genetic testing reported more than 4,300 carbapenem-resistant cases, 1,831 of them NDM-related. That represents a more than fivefold rise in NDM-linked infections in just four years.
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Public health experts say the findings are alarming. David Weiss, an infectious diseases researcher at Emory University, told the AP that the trend is “very worrisome.” CDC scientists added that many people could be undiagnosed carriers, raising the risk of wider community spread.
What Exactly Are ‘Nightmare Bacteria’?
The term refers to a group of germs called Carbapenem-resistant Enterobacteriaceae (CRE). These include familiar bacteria such as Klebsiella pneumoniae and Escherichia coli, which usually cause infections like pneumonia or urinary tract infections. What makes them “nightmarish” is that they no longer respond to carbapenems, antibiotics normally kept as a last resort option when other drugs fail.
The threat becomes greater when bacteria carry the NDM gene, which gives them the ability to block or “break down” multiple powerful antibiotics at once. In such cases, doctors are left with almost no treatment options.
The name itself highlights an India link. The NDM gene was first identified in New Delhi, and Al Jazeera has reported that such resistant strains are relatively widespread in South Asia, particularly in India and Pakistan. Antibiotic misuse, limited regulation of generics, and overcrowded hospitals have all contributed to this regional vulnerability.
Where Are Infections Being Reported?
The CDC study drew data from 29 US states that have surveillance and genetic testing systems in place. In 2023, these states recorded 4,341 carbapenem-resistant infections, including 1,831 involving NDM.
However, the report did not cover some of the most populous states: California, Florida, New York and Texas. This means the actual number of cases nationwide is likely far higher than recorded.
The CDC had, in a separate repor,t noted a steady increase in NDM infections in New York City between 2019 and 2024. Yet many hospitals across the country still lack the capacity to run the genetic tests needed to identify resistant strains, making underreporting a major challenge.
What Are The Symptoms And Warning Signs?
Detecting CRE infections is difficult because their early symptoms mimic those of ordinary infections. Still, clinicians warn that persistence despite antibiotic treatment should raise suspicion. Common presentations include:
- Urinary tract infections: burning sensation while urinating, cloudy urine, frequent urges.
- Pneumonia: cough, chest pain, fever and difficulty breathing.
- Bloodstream infections (sepsis): high fever, chills, confusion, low blood pressure and rapid heartbeat.
According to the CDC, some cases also involve wound infections, persistent fevers or gastrointestinal symptoms like diarrhoea and abdominal pain.
Why Are Cases Rising So Sharply In The US?
Between 2019 and 2023, carbapenem-resistant infections rose from under 2 cases per 100,000 people to more than 3. But NDM-linked infections grew much faster, from 0.25 to about 1.35 per 100,000, a 460 per cent jump.
Multiple factors lie behind this surge:
- Pandemic-era antibiotic use: During Covid-19, doctors prescribed antibiotics more widely to manage hospitalised patients. Jason Burnham, an infectious diseases researcher at Washington University in St Louis, told AP that this “huge surge in antibiotic use” likely fuelled resistance.
- Hospital vulnerabilities: Patients on ventilators, catheters or intravenous lines are at higher risk, particularly when infection control protocols falter.
- Travel and cross-border spread: Bacteria with the NDM gene were once linked to overseas medical care, but global movement has made them harder to contain.
- Misuse of antibiotics: Both unfinished prescriptions and unnecessary courses strengthen bacteria rather than eliminate them, giving rise to resistance.
How Dangerous Is The NDM Gene?
According to CDC researchers, only two drugs still work against NDM strains, both expensive and requiring intravenous administration.
Weiss of Emory University described the rise as a “grave danger.” Public health authorities warn that unchecked resistance could make once-manageable illnesses such as urinary tract infections or pneumonia far more difficult to treat, and could complicate even routine surgeries, since post-operative infections may no longer respond to standard therapies.
How Do These Bacteria Spread?
According to the CDC, most carbapenem-resistant and NDM infections start in healthcare settings, particularly among patients using ventilators, catheters or intravenous lines. According to Al Jazeera, poor sanitation and gaps in infection control can allow the bacteria to spread rapidly inside hospitals.
But the threat is no longer confined to medical facilities. Dr Maroya Walters, one of the CDC report’s authors, warned that if resistant strains spread in the wider community, even routine infections such as urinary tract infections could become much harder to treat.
The bacteria spread through multiple routes: direct person-to-person contact, contaminated medical equipment, and in regions with weaker regulation through unsafe food or water. International travel also plays a role, helping carry resistant bacteria across borders.
Why Is This A Global Threat?
Antibiotic resistance is not unique to the US. As per Al Jazeera:
- South Asia (India, Pakistan): NDM-producing bacteria widespread; overuse of antibiotics and overcrowded hospitals exacerbate spread.
- Southern Europe (Greece, Italy, Turkiye): Higher prevalence compared to northern Europe, where stewardship programmes are stronger.
- Africa: Underreporting common, but resistant strains present both in hospitals and communities due to weak sanitation and unregulated antibiotic sales.
- Latin America (Brazil, Argentina): Several outbreaks recorded in recent years.
A Nature study projected that antimicrobial resistance could cause as many as 40 million deaths by 2050 if left unchecked. Infections once easily treated could become fatal, and routine medical procedures from caesarean sections to cancer treatments could carry far greater risk.
How Can Individuals Protect Themselves?
Experts say individuals can help slow the spread of resistant bacteria by following simple steps:
- Wash your hands regularly with soap and water, especially after hospital visits or caring for the sick.
- Use antibiotics responsibly, only under medical supervision, never for viral infections like flu.
- Complete prescribed courses to ensure bacteria are fully eradicated.
- Get vaccinated, which helps prevent infections that might otherwise require antibiotic treatment.
- Check hospital infection controls – gloves, gowns, sterilisation protocols – when seeking care.
- Practise wound hygiene, keeping cuts and abrasions clean and covered.
- Be cautious while travelling in areas with high antibiotic resistance, paying attention to food and water safety.
About the Author
Karishma Jain, Chief Sub Editor at News18.com, writes and edits opinion pieces on a variety of subjects, including Indian politics and policy, culture and the arts, technology and social change. Follow her @kar…Read More
Karishma Jain, Chief Sub Editor at News18.com, writes and edits opinion pieces on a variety of subjects, including Indian politics and policy, culture and the arts, technology and social change. Follow her @kar… Read More
September 25, 2025, 11:06 IST
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