Health Letter, November 2020
By Azza AbuDagga, M.H.A., Ph.D.
Since the 1940s, antibiotics have been critical for treating common and complex bacterial and fungal infections, including those that lead to sepsis (the body’s excessive immune response to infection resulting in a drop in blood pressure, tissue damage, organ failure and often death). However, once an antibiotic is introduced, bacteria or fungi (germs) always change and develop new ways to defeat it. This process is called antibiotic resistance, and it is one of the greatest global public health challenges of our time.
In November 2019, the Centers for Disease Control and Prevention (CDC) released an important new report on this problem. The new report is an update of the agency’s first report on this topic, which was released in 2013. It provides the latest data that underscore the continued threat of antibiotic resistance in the U.S. and highlights the emerging areas of concern and actions needed to combat it.
Burden of antibiotic resistance
According to the new CDC report, nearly three million antibiotic-resistant infections occur in the U.S. every year, and more than 35,000 people die as a result of these infections. Additionally, nearly 223,900 Americans were hospitalized and at least 12,800 died in 2017 as a result of Clostridium difficile (C. difficile) infection — a complication of antibiotic treatment in which the C. difficile bacteria infects the intestines because of the death of the good bacteria in the gut, resulting in watery diarrhea, abdominal cramps, bloody stools and fever.
The new report used data sources that were not available when the agency released its first report and disclosed that the earlier report had woefully underestimated the impact of antibiotic resistance in the U.S. Nonetheless, the new report concluded that prevention efforts have reduced overall deaths from antibiotic-resistant infections by 18% since the previous report was published and decreased deaths from such infections in hospitals by more than 27% from 2012 to 2017.
In addition to the toll of infections and deaths, antibiotic-resistant infections add considerable costs to the U.S. health care system. In many instances, these infections require lengthy hospital stays, many follow-up visits to health care professionals, and the use of costly and potentially more toxic treatments.
Although everyone is at risk, antibiotic resistance disproportionately affects the most vulnerable — the young, the elderly and the critically ill, who also tend to suffer worse consequences from such infections.
The report listed 18 specific antibiotic-resistant germs and classified them into three threat categories — urgent, serious and concerning — based on their clinical and economic impacts, current and projected ten-year occurrence rate, transmissibility (how easily a germ spreads or causes infections), availability of effective antibiotics and barriers to prevention. The urgent threats include carbapenem-resistant Acinetobacter, Candida auris, C. difficile, carbapenem-resistant Enterobacteriaceae and drug-resistant Neiserria Gonorrhoeae (N. gonorrhoeae).
The report also added a new category — labeled watch list — that includes antibiotic-resistant germs that, although not currently a challenge in the U.S., have the potential to become so.
Notably, the top three germs that caused the highest estimated numbers of drug-resistant infections in 2019 were Streptococcus pneumoniae (900,000 infections), N. gonorrhoeae (550,000 infections) and Campylobacter (448,400 infections).
A complex web: Everything is connected
Any antibiotic use — in people, animals or crops — can lead to resistance. Therefore, the report emphasized that resistant germs are a “One Health” challenge because they also can spread between people, animals and the environment (particularly soil and water). For example, some resistant germs spread from person to person during activities, such as handshaking, working out or going to school. Others spread between people and animals through food (such as certain strains of Salmonella bacteria, which can make both cattle and people sick) or contact with pets and zoo animals. Other resistant germs spread through the environment. For example, carbapenem-resistant Enterobacteriaceae can survive and grow in sink drains in hospitals and spread to patients through the wastewater. Similarly, Aspergillus fumigatus, a common mold, can exist in crop fields treated with fungicides.
Like the coronavirus pandemic, antibiotic resistance is not only a U.S. problem — it is a global crisis: New forms of resistance arise and can spread with extraordinary speed between continents.
Stemming the tide of antibiotic resistance
As noted by Dr. Robert Redfield, CDC director, in his introduction to the new report, relying on new, more powerful antibiotics cannot be the only solution for resistant germs because there are not enough new antibiotics in the drug-development pipeline and “sadly, these germs will one day render [them] ineffective” anyway. Instead, the report emphasized prevention, containment and antibiotic stewardship (implementing measures to stop the misuse and overprescribing of antibiotics) as vital strategies to combat antibiotic resistance.
Specifically, the prevention and containment strategies focus on the early detection (using national alert systems) and aggressive responses at the first sign of a new or unusual strain of antibiotic-resistant germs. When deployed at the first sign of a problem, these strategies keep new or unusual forms of resistant germs from spreading. For example, the CDC identified an outbreak of carbapenem-resistant Pseudomonas aeruginosa with an unusual form of resistance among more than 20 people across several states in 2018 that originated in patients who had surgeries at a Mexican hospital. The agency partnered with other organizations in the U.S. and internationally and implemented an immediate containment strategy (including notifying hundreds of patients about their risk of possible exposure), which helped to protect these patients and contained the spread of this resistant strain.
Antibiotic stewardship is a critical strategy because the CDC estimated that 30% of the 269 million outpatient antibiotic prescriptions dispensed in 2015 alone in the U.S. — enough for five out of every six people to receive one antibiotic prescription annually — are unnecessary.
What You Can Do
To reduce your and your family’s risk of antibiotic-resistant infection, the CDC recommends that you wash your hands regularly, learn how to prepare food safely and practice healthy habits around animals. In addition, know your risks for certain infections, and learn how to recognize signs and symptoms of infections; clean and cover cuts and wounds until they are healed; and control chronic health conditions (such as diabetes or heart disease).
Consult your doctor or veterinarian about the best treatment if you, your family member or a pet become sick and avoid using antibiotics inappropriately or unnecessarily.
Get the CDC-recommended vaccinations and take measures to avoid sexually transmitted diseases. Also, stay healthy when traveling abroad by avoiding places with known infectious disease outbreaks and by not consuming potentially contaminated drinks and foods.
 Centers for Disease Control and Prevention. Antibiotic resistance threats in the United States, 2019. November 2019. https://www.cdc.gov/drugresistance/pdf/threats-report/2019-ar-threats-report-508.pdf. Accessed July 23, 2020.
 Centers for Disease Control and Prevention. Antibiotic resistance threats in the United States, 2013. April 2013. https://www.cdc.gov/drugresistance/threat-report-2013/pdf/ar-threats-2013-508.pdf. Accessed July 23, 2020.
 Centers for Disease Control and Prevention. Antibiotic prescribing and use. August 8, 2019. https://www.cdc.gov/antibiotic-use/stewardship-report/outpatient.html. Accessed July 23, 2020.