Contrary to established belief, hospital-acquired infections are not predominantly caused by ‘superbugs’ present in healthcare facilities. Most infections occur due to bacteria that patients carry with them when they enter the hospital. A recent study in the field of genomics draws attention to this overlooked fact: the majority of hospital-acquired infections originate from bacteria that had previously been present, and harmless, in the patients’ own bodies.
In our study, published in Science Translational Medicine, we focused on bacterial flora – microorganisms colonizing various areas such as our skin, nasal passages, and other parts of the body. We discovered that these ordinarily harmless bacteria cause several health issues like pneumonia, diarrhea, bloodstream infections, and surgical site infections. It is notable that these are the very organisms that live harmlessly within us when we are healthy.
Our research further demonstrated that a great number of surgical site infections following spinal surgeries were caused by microbes that were already present on the patient’s skin. Surgical site infections stand out as particularly troublesome amongst other healthcare-acquired infections. A 2013 study estimated that surgical site infections accounted for over 33 percent of the total $9.8 billion spent annually in the United States on hospital-acquired infections. These infections pose a considerable risk for hospital readmission and postoperative mortality.
Despite rigorous preventive measures enacted by hospitals, which encompass sterilizing surgical equipment, cleaning operating rooms with ultraviolet light, strict adherence to surgical gowning protocols, and the control of operating room airflow, surgical site infections still occur after approximately one in every 30 operations.
Data from the Agency for Healthcare Research and Quality and the Centers for Disease Control and Prevention highlight a worrying trend—the rate of surgical site infections has remained stagnant. Unfortunately, the increased global resistance to antibiotics, owing partly to prophylactic use during surgeries, could potentially escalate the rate of postoperative infections.
Our interdisciplinary team of researcher-clinicians employed the latest genetic analysis methods to shed light on the origin of these infections. Unlike previous studies that were limited to a single bacterial species, recent technological advancements allowed us to study a panoply of bacteria and their antibiotic-resistant genes simultaneously.
Specifically, our focus was spinal surgery infections due to the large number of people who undergo spine surgeries and the substantial healthcare resources expended on this surgical intervention. Additionally, spine surgery infections are notably high stakes—they often necessitate further surgeries and prolonged treatment with antibiotics.
We observed that the bacterial species residing on our skin vary greatly between individuals, but some patterns emerge. For instance, bacteria inhabiting the upper back (around the neck and shoulders) are more akin to those in our noses, while bacteria on the lower back resemble those in our gut and stool. Intriguingly, the prevalence of these bacteria in certain areas often matches the frequency at which they cause infections following surgeries on the corresponding regions of the spine.
Overwhelmingly, 86 percent of bacteria causing infections following spinal surgeries were genetically identical to those present on the patient prior to surgery. Nearly 60 percent of the infections were also resistant to the prophylactic antibiotics used during surgery, suggesting that antibiotic-resistant bacteria were not acquired in the hospital but were resident bacteria in the patients themselves.
Although these findings may seem intuitive that surgical infection organisms originate from the body part being operated on, they have significant implications for infection prevention measures. For instance, broad-brush protocols, like the use of a standard antibiotic across the board, could be replaced by a more personalized approach, enabling medical professionals to select more targeted antimicrobials based on a patient’s microbiome. Still, more research is needed to ascertain whether such individualized approaches would improve patient outcomes.
While current preventive protocols largely focus on maintaining a sterile physical environment, our research highlights the need for more patient-centered preventative methods. The fact that most infections originate within the patient rather than the hospital may call for a paradigm shift towards individualized approaches to infection prevention, potentially benefitting both patients and healthcare providers alike.
Source: https://www.sciencealert.com/scientists-reveal-where-most-hospital-infections-actually-come-from