The news is dismaying, but not surprising to officials who have been watching waves of patients swamp hospitals—in 2020, because there were no vaccines and few effective treatments; in 2021, because vaccines are being refused. “We really had a perfect storm when it comes to health-care-associated infections and Covid,” says Arjun Srinivasan, a physician and associate director of the CDC’s program for preventing those infections.
During the first waves, he points out, the patients most likely to come into hospitals with severe Covid were older, with chronic illnesses, possibly immunocompromised—and as a result, more likely to end up in an ICU and need ventilation tubes to take over breathing and ports into their bloodstreams to deliver medications. With so many patients, health care workers were stretched thin, more at risk of skipping preventive tasks—and with PPE in such short supply, more at risk of unknowingly carrying pathogens between patients. “So at the same time you have more patients than you’ve ever had before, you have fewer staff than you would normally have to take care of them,” Srinivasan says. “Normal systems of care delivery break down, because you’ve just got too much demand for care, and not enough health care providers to provide it.”
There was an uneasy expectation last year that this might happen. In November, a team of researchers from New York and St. Louis predicted in the American Journal of Infection Control that as Covid advanced, people with less acute illnesses or postponable surgeries would be less likely to check into hospitals. They forecast that that would lead to an increase in patients with severe illness who would need the kind of interventions that lead to hospital infections. They based that prediction on early signals from their own institutions: In the first three months of the US pandemic, central-line-associated bloodstream infections rose by 420 percent in one hospital and 327 percent in another, compared to the previous 15 months.
“In my institution, Covid came to us in mid-March 2020, and April was the worst month of hospital infections in the history of our hospital,” says Kathleen M. McMullen, senior manager of infection prevention and occupational health at Christian Hospital and Northwest Healthcare in St. Louis and first author of that study. “Talking to colleagues nationally, we heard they were dealing with it also, and thought ‘We need to get this out.’”
The team also foresaw that some categories of infections, such as ones that take hold in surgical incisions, would diminish as elective surgeries were postponed. Their instincts were solid. The CDC’s new data shows that the only types of hospital infections to decline last year were surgical-site infections following colon surgery or hysterectomy (the kind that requires an open incision, not those done by laparoscopy), and also C. difficile, the pernicious intestinal infection that surges when broad-spectrum antibiotics disrupt the balance of intestinal bacteria.
All of that made sense, given the conditions hospitals were enduring in that first wave, McMullen says: “There were so many patients, not many more health care workers, and so much fear—of not being comfortable, of wanting to get in and out of a patient’s room quickly.”
The data the CDC uncovered matches what McMullen and her colleagues observed and then predicted. But she says it may actually underrepresent hospital infections across the country, because the labor of caring for patients in that first wave was so intense that the federal Center for Medicare and Medicaid Services allowed hospitals to suspend mandatory reporting between April and June.
There’s an especially foreboding signal within the CDC’s data. One of the infections that spiked, rising by a third between the end of 2019 and the end of last year, was bacteremia—dissemination of infectious bacteria throughout the bloodstream, which can lead to sepsis and septic shock—caused by MRSA. It was the only drug-resistant infection appearing in their data because it is among the infections that CMS requires to be reported. (MRSA and all staph bacteria live on the skin, so piercing it with a catheter or incision can conduct the bacterium inside the body.)