(CNN) Years of progress the United States had made in fighting drug-resistant infections were largely erased during the Covid-19 pandemic, with hospital-acquired infections and resulting deaths growing 15% in 2020.
A special report released Tuesday by the US Centers for Disease Control and Prevention found that more than 29,400 people died from antimicrobial-resistant infections in 2020. The full number is likely much higher, given that data for half of the 18 pathogens identified as threats are unavailable or delayed.
Nearly 40% of those deaths were among people who got the infection while in the hospital, according to the CDC report.
Between 2012 and 2017, deaths from antimicrobial resistance dropped 18% overall and nearly 30% in hospitals. But in 2020, deaths and acquired in the hospital grew by 15%.
"Antimicrobial resistance was one of our greatest public health concerns prior to the COVID-19 pandemic, and it remains so," CDC Director Dr. Rochelle Walensky wrote in foreword to the report.
The World Health Organization has called antimicrobial resistance a "silent pandemic," and drug-resistant infections were linked to nearly 5 million deaths globally in 2019.
The Covid-19 pandemic likely contributed to the increased risk in the United States in multiple ways, according to the CDC report.
People who delayed care or left infections untreated -- perhaps because of closed clinics or changes in personal health care-seeking behavior to reduce risk of exposure to Covid-19 -- could have increased the risk of developing drug resistance.
Also, between March 2020 and October 2020, nearly 80% of patients hospitalized with Covid-19 received an antibiotic. This is an ineffective treatment for a viral disease that can "put patients at risk for side effects and create a pathway for resistance to develop and spread," according to the report.
Hospitals were also treating more and sicker patients. Staffing shortages, limited personal protective equipment and patients that required longer stays, including longer use of medical devices such as catheters and ventilators, created challenges in following established infection prevention and control guidance.
Among the pathogens that the CDC considers of urgent concern are acinetobacter, a bacteria that can cause pneumonia, blood or urinary tract infections, which increased 35% overall and 78% in hospitals in 2020; candida auris, a fungus that is most common in long-term care facilities, which increased 60% overall in 2020; and neisseria gonorrhoeae, the bacteria that causes the sexually-transmitted disease gonorrhoea.
Going forward, the CDC plans to focus on continued infection control training, efforts to manage how antibiotics and antifungals are prescribed and used, advancing research for treatments, tracking pathogens in the community using wastewater, or sewage, and expanding data networks.
WHO said that only one of the six top pathogens causing drug-resistant infections has a vaccine. In a report published Tuesday, the agency identified 61 vaccines in various stages of clinical development and called for their urgent development for an equitable response to antimicrobial resistance.
"This setback can and must be temporary. The COVID-19 pandemic has unmistakably shown us that antimicrobial resistance will not stop if we let down our guard; there is no time to waste," said Michael Craig, director of the CDC's Antibiotic Resistance Coordination & Strategy Unit.
"The best way to avert a pandemic caused by an antimicrobial-resistant pathogen is to identify gaps and invest in prevention to keep our nation safe."