Washington: Health authorities in the United States are raising alarms over a sharp increase in infections caused by drug-resistant bacteria, often referred to as “nightmare bacteria”. A new report from the Centers for Disease Control and Prevention (CDC) shows that infections by these dangerous bacteria rose by almost 70 percent between 2019 and 2023.
Researchers attribute the surge to bacteria carrying the New Delhi metallo-β-lactamase (NDM) gene. Once considered exotic and mostly found in a few patients outside the United States, these bacteria are now appearing with increasing frequency across the country. The presence of the NDM gene can render carbapenems, the last line of defense in antibiotics, completely ineffective.
David Weiss, an infectious diseases researcher at Emory University, told The Associated Press, “The rise of NDMs in the US is a grave danger and very worrisome.”
CDC researchers collected data from 29 states that test for carbapenem-resistant bacteria. They reported 4,341 infections in 2023, including 1,831 cases involving NDM-gene bacteria.
Antimicrobial resistance occurs when bacteria evolve ways to survive drugs designed to kill them. Misuse of antibiotics, such as not completing prescribed courses or receiving unnecessary prescriptions, allows bacteria to adapt and spread their resistance genes to other bacteria.
The rate of carbapenem-resistant infections climbed from just under 2 per 100,000 people in 2019 to over 3 per 100,000 in 2023, a 69 percent increase. NDM-gene infections increased even more dramatically, from about 0.25 to 1.35 per 100,000, marking a staggering 460 percent rise.
CDC scientists warn that some people may carry these bacteria without knowing it, raising the risk of wider community spread. Common infections, including urinary tract infections, could become much more dangerous if treatment fails.
Experts also say that the COVID-19 pandemic may have contributed to the rise in drug-resistant bacteria. There was a huge surge in antibiotic use during the pandemic, so this likely is reflected in increasing drug resistance.
The CDC acknowledges that its figures may underrepresent the true scale, as many states do not routinely test for these infections and data from major population centres, such as California, Florida, New York and Texas are missing.
Carbapenem-resistant Enterobacteriaceae (CRE) infections are difficult to detect because symptoms resemble common bacterial illnesses. Warning signs include urinary tract infections with burning or cloudy urine, bloodstream infections with fever and rapid heartbeat and pneumonia with cough, shortness of breath or chest pain.
NDM-gene bacteria are not confined to the United States. South Asia, especially India and Pakistan, shows widespread prevalence due to overuse of antibiotics, overcrowded hospitals and limited regulation. Southern Europe, including Greece, Italy and Turkiye, also reports higher cases than northern countries with stronger infection control and stewardship programmes.
Africa has limited data, but resistant bacteria exist in hospitals and communities, often worsened by unregulated antibiotic use and weak sanitation. In Latin America, Brazil and Argentina have recorded several outbreaks in recent years.
Experts stress that antibiotic-resistant bacteria are a global health security threat. They can spread easily through people, food and animals. Countries with weaker healthcare systems and lax antibiotic regulations are at higher risk. The CDC warns that rising drug-resistant infections require urgent attention, coordinated action and responsible antibiotic use worldwide.