The World Health Organization classifies sepsis as a life-threatening condition that occurs when the body’s immune system has an extreme response to an infection, causing damage to its own tissues and organs. It can lead to shock, multiple organ failure, and death, particularly when not recognized early. Sepsis kills roughly one million newborns and up to 100,000 mothers every year, and the WHO considers it a global health priority requiring coordinated action from all member states.
How the WHO Defines Sepsis
The WHO describes sepsis not as an infection itself, but as what happens when the body’s defense against an infection goes haywire and starts attacking healthy tissue. Instead of fighting the invading bacteria, virus, or fungus, the immune system triggers widespread inflammation that damages organs throughout the body. This organ dysfunction is the defining feature that separates sepsis from a routine infection.
Bacterial infections cause most cases, but viral infections like influenza and fungal infections can also trigger sepsis. The common warning signs are fever, fast heart rate, rapid breathing, confusion, and body pain. These symptoms can appear with many illnesses, which is part of what makes sepsis so dangerous: it’s easy to miss until it has progressed.
Why the WHO Treats Sepsis as a Global Emergency
In 2017, the World Health Assembly passed Resolution WHA70.7, formally recognizing sepsis as a major threat to patient safety and global health. The resolution called on all member states to develop standards, guidelines, laboratory infrastructure, and strategies to reduce sepsis cases and deaths. It also pushed for collaboration between UN organizations, international partners, and public health stakeholders to improve both treatment and prevention, including through vaccination programs.
The resolution has four core pillars: prevention, diagnosis, clinical management, and international collaboration. A central theme is that sepsis disproportionately affects countries with weaker healthcare systems, where basic infection control measures, clean water, and adequate staffing may be lacking.
Who Is Most Vulnerable
Newborns and pregnant women face some of the highest risks. Sepsis claims approximately one million newborn lives per year and kills up to 100,000 women during or after pregnancy. In countries like Rwanda and Uganda, where other major causes of maternal death (hemorrhage, preeclampsia) have been reduced through years of effort, sepsis has become the leading cause of maternal mortality.
Diagnosing sepsis in newborns and pregnant women is particularly difficult because early symptoms can be subtle or mimic other conditions. By the time sepsis becomes obvious, it may already be severe and advanced, with a significantly reduced chance of survival. The WHO has also raised concern that global efforts to encourage facility-based deliveries may inadvertently worsen the problem. Many health facilities lack proper infection prevention protocols, have high rates of cesarean sections (which increase infection risk), and face overcrowding and understaffing. Mothers and babies are sometimes discharged before sepsis can be recognized.
Children also face unique diagnostic challenges. In 2024, an international consensus established the Phoenix Sepsis Score as the standard tool for identifying sepsis in children under 18. This replaced older criteria based on systemic inflammatory response, which were found to be too broad. The new score focuses on dysfunction in four organ systems: respiratory, cardiovascular, coagulation, and neurological. A score of 2 or higher in a child with suspected infection now meets the criteria for sepsis.
How Sepsis Is Diagnosed
No single laboratory test can confirm sepsis. Diagnosis relies on a combination of clinical signs and lab results that together paint a picture of organ dysfunction. Doctors typically start with basic blood work: white blood cell counts, markers of kidney and liver function, platelet counts (which reflect the blood’s ability to clot), and arterial blood gases to assess lung function.
One of the most important markers is lactate, a substance that builds up in the blood when tissues aren’t getting enough oxygen. A lactate level above a certain threshold is part of the formal definition of septic shock, the most dangerous stage of the condition. Serial lactate measurements are also used to track whether treatment is working.
Blood cultures help identify the specific bacteria, fungus, or virus causing the infection, which guides treatment decisions. Newer rapid diagnostic platforms can test for over two dozen bacterial and yeast pathogens plus antibiotic resistance markers from a single blood culture sample, dramatically shortening the time to targeted treatment. These tools are increasingly available but remain out of reach in many lower-resource settings, which is a key concern for the WHO.
The Link to Antibiotic Resistance
Antimicrobial resistance (AMR) and sepsis are deeply connected. When the bacteria causing an infection are resistant to standard antibiotics, treatment is delayed or less effective, giving sepsis more time to progress. An estimated 10% of sepsis deaths worldwide are attributable to antimicrobial resistance. This makes antibiotic stewardship, the practice of using antibiotics carefully and only when needed, a critical part of the WHO’s sepsis prevention strategy.
Prevention Strategies the WHO Recommends
Because sepsis starts with an infection, preventing infections is the most effective way to prevent sepsis. The WHO emphasizes infection prevention and control (IPC) at every level: in hospitals, clinics, and communities. Hand hygiene is a cornerstone. The WHO’s annual “Save Lives: Clean Your Hands” campaign on May 5 specifically highlights the role of hand hygiene in preventing sepsis in healthcare settings.
Beyond hand washing, the WHO advocates for clean water, sanitation, and hygiene infrastructure in health facilities as a baseline requirement. The joint WHO/UNICEF Global Action Plan for water, sanitation, and hygiene in healthcare facilities recognizes that sustained improvements in these basic services are essential for reducing healthcare-associated infections that lead to sepsis. Vaccination is another prevention pillar, since immunizing against common pathogens like influenza and pneumococcal disease reduces the infections that can trigger sepsis in the first place.