Sepsis was linked to one in five deaths worldwide in 2017
Sepsis is not an infection itself but the body's runaway reaction to one, damaging its own organs. In 2017 it affected about 49 million people and was tied to 11 million deaths, one in five worldwide. Most cases occur in low and middle income countries, 40% of them in Sub-Saharan Africa.
The usual picture is fever, a racing heart, fast breathing and confusion, plus signs of the original infection such as a cough with pneumonia. The very young, the old and those with weakened immunity may show none of that, and their temperature can even be low. When blood pressure stays dangerously low despite fluids, or needs drugs to prop it up, the condition is called septic shock. Early on, the lower blood pressure reading falls first, widening the gap between the two numbers; a gap above 70 mmHg is associated with better survival.
Bacteria are the commonest culprits, though fungi, viruses and parasites can also be responsible. The balance has shifted over time: Gram-positive bacteria dominated before antibiotics arrived in the 1950s, Gram-negative species took over from the 1960s to the 1980s, and since then Gram-positive bacteria, especially staphylococci, are thought to cause more than half of cases. Between 40 and 60% of infections behind sepsis start in the lungs, with the abdomen and urinary tract next.
The immune response is the real danger. Invading microbes are spotted by molecular patterns such as the endotoxin in some bacterial walls, triggering a flood of inflammatory signals, sometimes a cytokine storm, and white cells are summoned throughout the body instead of just to the infection. A second phase can follow in which immunity collapses as lymphocytes die off. Tissues may then stop using oxygen efficiently, possibly as a protective hibernation, and organs fail.
Doctors now screen with the quick SOFA score, which flags patients showing two of three signs: rapid breathing, altered consciousness and low blood pressure. Treatment is intravenous fluids and antimicrobials straight away, often followed by intensive care, drugs to raise blood pressure, ventilation or dialysis. Corticosteroids remain contested. The risk of death reaches 30% for sepsis and 80% for septic shock.
Source: Sepsis
