Sepsis Diagnosis Is Critical in the Age of Antibiotic Resistance

Sepsis is a life-threatening emergency caused by the body’s extreme response to infection, requiring rapid diagnosis and treatment to prevent organ failure and death.

1. No Single Test – Diagnosing sepsis relies on multiple tests and symptom monitoring, with procalcitonin (PCT) aiding in distinguishing bacterial infections.
2. High-Risk Groups – Elderly individuals, immunocompromised patients, and those with chronic conditions are more susceptible to both community- and hospital-acquired sepsis.
3. Antibiotic Stewardship – Proper antibiotic use, guided by tests like PCT, helps combat antibiotic resistance and ensures effective sepsis treatment.

Sepsis is a life-threatening medical emergency that occurs when the body’s immune system has an extreme response to infection. Commonly—and ominously—known as “blood poisoning,” sepsis requires urgent diagnosis and treatment, as it can quickly lead to tissue damage, organ failure, and death if not treated promptly. Sepsis was a leading cause of death in U.S. hospitals in 2024, according to the U.S. Centers for Disease Control and Prevention, affecting at least 1.7 million patients nationwide with 350,000 succumbing to infection.¹

As important as a rapid diagnosis is for sepsis patients, there is no single definitive test that clinicians can use to determine a diagnosis. Doctors, instead, rely on a number of different blood tests and monitor patient symptoms in combination with confirmatory diagnostics like procalcitonin (PCT), which is specific for bacterial infection. Time to treatment is the most critical factor for suspected sepsis patients. According to the Sepsis Alliance, clinicians need to pay special attention to:

• Temperature: higher or lower than normal
• Infection: showing signs and symptoms of infection (chills, cough, tachycardia, etc.)
• Mental decline: confused, sleepy, or difficult to rouse
• Extremely ill: in severe pain or discomfort, experiencing shortness of breath

Once a patient is believed to have sepsis based on symptoms and initial testing, a PCT test can be used to rule in or rule out bacterial infection. A PCT test measures the level of the procalcitonin protein in the blood, and patients with bacterial infection will show an elevated concentration. If testing finds low levels of PCT, a doctor may rule out bacterial infection and instead consider viral infection or other illness. Procalcitonin plays an important role in determining whether an infection is bacterial in nature, as opposed to other causes such as a virus, a fungus, or something else. Understanding the organism causing infection is critical to providing effective treatment, as well as adhering to hospital antibiotic stewardship protocols.

Everyone is at risk for developing sepsis, whether it’s acquired in a community or hospital setting. However, certain populations are more susceptible, including adults over 65, those with weakened immune systems, pregnant women, and infants. Additionally, chronic conditions such as heart disease, chronic obstructive pulmonary disease (COPD), diabetes, and cancer present an elevated risk for both community- and hospital-acquired sepsis.

In cases of community-acquired sepsis, leading causes include gastrointestinal infection; respiratory conditions, such as pneumonia; and urinary tract infection. Given the urgent need for treatment, these patients are typically admitted directly to the intensive care unit (ICU). With hospital-acquired sepsis, patients may enter the hospital for an unrelated condition then develop infection through bacteria that are present in the hospital environment. These commonly include Staphylococcus aureus, Pseudomonas aeruginosa, Enterobacteriaceae, and Candida species.

ICU patients and those requiring surgery, invasive procedures, or longer lengths of stay have a significantly increased risk of developing hospital-acquired infection. Furthermore, hospital-acquired sepsis has a significantly higher mortality rate than community-acquired sepsis. 

First-line sepsis treatment includes broad-spectrum antibiotics to fight the underlying infection. However, antibiotics are only effective against bacterial infection and do little to combat viral or fungal infection. This is why confirmatory tests like PCT are so important to facilitate both effective and responsible patient care. This can help avoid the overprescribing of antibiotics, minimize side effects of unnecessary antibiotics, and prevent development of antibiotic-resistant bacteria strains.

Antibiotic resistance occurs when bacteria evolve to survive the impact of antibiotics, making certain drugs ineffective against infections. Bacterial resistance can develop naturally, but is accelerated by the misuse and overuse of antibiotics. For example, when antibiotics are used without confirming the presence of bacterial infection. Other causes of antibiotic resistance include poor personal and hospital hygiene leading to the spread of infection, as well as gene transfer between bacteria that can share resistance genes.

Regardless of how it happens, when bacteria develop defenses against antibiotics in and out of the hospital, antibiotic resistance poses significant challenges to treating an infection, including infections that can lead to sepsis. As more germs become resistant, the risk of developing sepsis increases, because infections become harder to control and treat.

While antibiotic resistance is on the rise, healthcare professionals are fighting back by designing and implementing effective antibiotic stewardship programs. Antibiotic stewardship refers to the strategies employed by hospitals, physicians and healthcare providers to ensure antibiotics are used appropriately and only when necessary. Another cornerstone of antibiotic stewardship programs is practicing good hygiene and infection prevention measures.

When implemented consistently, antibiotic stewardship programs have shown to reduce antibiotic resistance and improve patient outcomes, while saving money and resources. Stewardship also allows patients to receive the most effective treatment option, which is essential to possible quick recovery.

Again, this is where PCT testing plays an important role. In addition to helping clinicians determine which patients have bacterial infections prior to administering antibiotic therapy, PCT is also used for monitoring treatment. By providing a quantitative measure of bacterial load, clinicians can measure the response to antibiotic treatment and, importantly, end a course of antibiotics as quickly as possible. This not only aids in patient recovery but reduces the risk of antibiotic resistance and minimizes antibiotic side effects. 

Sepsis and its relationship to antibiotic resistance is a health crisis that requires the ongoing vigilance of communities and healthcare providers. Antibiotic resistance not only complicates the treatment of infections like sepsis, but also increases risk of infection across the population by weakening the efficacy of life-saving antibiotic treatment. Together, with the support of the public and greater awareness of the issues and challenges, we can embrace more effective treatment strategies and responsible antibiotic use. 

To learn more about sepsis, patient safety, and antibiotic stewardship, tune into the latest podcast from QuidelOrtho.

Lindy Crimmins, MD, is a global medical affairs manager at QuidelOrtho. Her clinical experience spans from emergency medicine to critical care and primary care. Currently, she is responsible for providing medical support for the QuidelOrtho acute care menu throughout the product lifecycle.

Rhee C, Dantes R, Epstein L, et al. Incidence and Trends of Sepsis in US Hospitals Using Clinical vs Claims Data, 2009-2014. JAMA. 2017;318(13):1241-1249. doi:10.1001/jama.2017.13836

https://clpmag.com/disease-states/sepsis/sepsis-diagnosis-is-critical-in-the-age-of-antibiotic-resistance/