NDM-CRE Infections Surge: CDC Warns of Rising Drug-Resistant Bacteria

The Centers for Disease Control and Prevention (CDC) has issued a new report highlighting a dramatic increase in a particularly dangerous type of drug-resistant bacteria, NDM-producing carbapenem-resistant Enterobacterales (NDM-CRE). This surge, documented in research published in the Annals of Internal Medicine, poses a growing threat to public health, limiting treatment options for serious bacterial infections.

Between 2019 and 2023, NDM-CRE infections in the United States surged by more than 460%. These infections, which can manifest as pneumonia, bloodstream infections, urinary tract infections, and wound infections, are notoriously difficult to treat and can be fatal. The rise in NDM-CRE is particularly concerning because it threatens to increase both the number of infections and the number of deaths associated with carbapenem-resistant Enterobacterales (CRE) overall. A 2022 CDC special report on the impact of COVID-19 on antimicrobial resistance noted approximately 12,700 CRE infections and 1,100 deaths in the U.S. In 2020, suggesting a baseline level of risk even before the recent, sharp increase.

Understanding NDM-CRE and Carbapenem Resistance

NDM-CRE belongs to a group of bacteria known as carbapenem-resistant Enterobacterales (CRE). CRE are resistant to carbapenems, a class of powerful antibiotics often used as a last resort to treat infections caused by other, more common bacteria. The “NDM” component refers to New Delhi metallo-β-lactamase, an enzyme produced by these bacteria that renders them resistant to nearly all available antibiotics. This leaves clinicians with very few effective treatment options.

The increasing prevalence of NDM-CRE is not simply a matter of antibiotic resistance; it’s a case of extensive resistance. Because NDM-CRE has historically been uncommon in the United States, healthcare providers may not immediately suspect it when treating patients with CRE infections, potentially leading to the selection of ineffective treatments. This underscores the importance of rapid and accurate diagnostic testing.

Challenges in Detection and Treatment

One significant hurdle in combating NDM-CRE is the challenge of detection. Many clinical laboratories currently lack the necessary testing capacity to identify these specific bacteria quickly and accurately. Delayed identification can lead to slower treatment initiation, increased transmission of the bacteria within healthcare settings, and missed opportunities for implementing effective infection control measures.

Effective treatment options for NDM-CRE infections are limited. The CDC report emphasizes that selecting the right treatment is now more complicated than ever, necessitating access to testing to guide targeted therapies. The report doesn’t detail specific treatment protocols, but highlights the urgency of identifying the resistance mechanism to inform antibiotic selection.

Factors Contributing to the Surge

The exact reasons behind the dramatic increase in NDM-CRE infections are still under investigation. However, the CDC identifies several potential contributing factors. Gaps in infection control practices – such as inconsistent hand hygiene, inadequate use of personal protective equipment (PPE) like gloves and gowns, and insufficient cleaning and disinfection protocols – can facilitate the spread of bacteria like NDM-CRE within healthcare facilities. Contact Precautions, as outlined by the CDC, are crucial in these settings.

Limited testing capacity also plays a role. Without widespread and rapid testing, NDM-CRE infections can go undetected, allowing the bacteria to spread unnoticed. This represents particularly concerning in long-term care facilities, where vulnerable populations are at higher risk. Enhanced Barrier Precautions are recommended in these facilities.

What Healthcare Providers Can Do

The CDC is urging healthcare providers to take several steps to address this growing threat. These include staying informed about the increasing prevalence of NDM-CRE nationally and understanding the local epidemiology of CRE infections. Prompt testing to identify the specific carbapenemase present is crucial for guiding appropriate treatment decisions. Testing is available through some clinical laboratories and, when unavailable locally, through public health laboratories.

Strengthening infection prevention and control practices is also paramount. This includes adhering to established guidelines for hand hygiene, PPE use, and environmental cleaning and disinfection. Collaboration with state and local Healthcare-associated Infections and Antimicrobial Resistance (HAI/AR) Programs can further support prevention efforts.

The Broader Context of Antimicrobial Resistance

The rise of NDM-CRE is not an isolated incident. It’s part of a larger, global trend of increasing antimicrobial resistance. The overuse and misuse of antibiotics, both in human medicine and agriculture, contribute to the development and spread of resistant bacteria. The COVID-19 pandemic also appears to have exacerbated the problem, as the 2022 CDC report detailed the impact of the pandemic on antimicrobial use and resistance patterns.

Looking Ahead: Surveillance and Prevention

Addressing the challenge of NDM-CRE and other drug-resistant bacteria requires a multi-faceted approach. Continued surveillance is essential to track the spread of these organisms and identify emerging resistance patterns. Investment in research and development of new antibiotics and alternative therapies is also critical. Promoting responsible antibiotic use and strengthening infection control practices are vital steps in slowing the spread of antimicrobial resistance. The CDC’s CRE information page and the Antimicrobial Resistance Laboratory Networks provide further resources and updates on this evolving public health threat.