Life-threatening infections caused by invasive group A streptococci (iGAS) are decreasing in Denmark after a significant surge following the COVID-19 pandemic. According to a report by Statens Serum Institut (SSI), the incidence of these severe infections, including “flesh-eating bacteria,” rose dramatically but is now showing signs of returning to pre-pandemic levels.

In 2023, 625 cases of iGAS were recorded, nearly triple the pre-pandemic average of 220-240 cases annually. However, the number fell to 343 in 2024, and the first four months of 2025 saw 118 cases, compared to 194 during the same period in 2024.

Experts attribute the initial surge to an “immunity debt” resulting from COVID-19 lockdowns, where reduced exposure to common infections weakened immune defenses across the population. This increased susceptibility to iGAS, which can penetrate sterile areas of the body and cause life-threatening conditions such as lung infections, meningitis, blood poisoning, and tissue death.

Elderly individuals over 65 are particularly vulnerable, with a mortality rate of 13 percent. Between 2022 and 2023, 76 cases and three deaths were recorded among children.

One survivor, Joachim, recounted his near-fatal experience with flesh-eating bacteria, which led to septic shock and cardiac arrest. He emphasized the unpredictable nature of the disease and the importance of awareness.

Despite the decline in cases, health officials remain vigilant. Charlotte Munkstrup from SSI notes that while the factors contributing to the previous surge are diminishing, continuous monitoring is essential to maintain the downward trend and prevent future outbreaks.