Necrotizing soft tissue infections (NSTI) are rare and life-threatening bacterial infections characterized by necrosis of subcutaneous tissue, fascia, or muscle. Few prospective studies have been conducted. The primary objective is to assess the 90-day mortality rate and to identify prognostic factors in patients with NSTI in an international setting. Secondary objectives are i) to characterize the clinical and microbiological presentation and management; ii) to assess the risk of limb amputation and associated factors; and iii) to assess functional and health-related quality of life (HRQoL) outcomes and associated factors.

We are conducting a multinational, prospective, non-interventional cohort study. We plan to enroll 1,033 consecutive patients admitted to 85 hospitals with surgically proven NSTI between November 2021 and December 2024 in 17 countries over three continents. Data will be collected prospectively on a secure web-based server. The primary outcome measure will be the day-90 mortality. Secondary outcomes include need for limb amputation, the activity of daily living scale and health-related quality of life at day-90 (EQ-5D-5L questionnaire). Baseline characteristics associated with outcomes will be identified by multivariable analyses. Exploratory analyses will be conducted to assess the impact of therapeutic interventions on day-90 mortality and secondary outcomes. The study protocol has been approved by an ethics committee in each participating country.