Reconstructive, functional and psychological outcomes in invasive group A streptococcal soft tissue infections: a 10-year retrospective cohort study 2013–2022

Studies have identified significant morbidity and mortality with necrotising soft tissue infections relating to invasive group A Streptococcus (iGAS). However, no studies have analysed the reconstructive, functional and psychological outcomes of invasive group A Streptococcus infections across its clinical spectrum, including the more common non-necrotising presentations. This study was a retrospective cohort study that aimed to review as primary outcomes the management, reconstructive burden and functional outcomes of soft tissue iGAS infections at a tertiary-care U.K. Plastic Surgery unit between 2013 and 2022. The secondary outcome was to identify associations between patient factors and limb amputation and mortality. All positive iGAS cultures isolated in patients aged 16 and over were identified. Medical records, operative records, and microbiology samples were examined. 96 cases of iGAS were identified in 95 patients over the study period. 63 patients (66%) were male; 34 patients (36%) were current smokers; and 35 patients (37%) were immunocompromised, including 18 patients (19%) with diabetes. 88 cases (92%) affected the upper or lower limbs, with 11 cases (13% of limb iGAS) requiring amputation of the involved digit or limb. Reconstructive surgery was performed in 15 cases (16%), requiring a mean number of 3.7 ± 1.88 operations. Reconstruction methods involved acelluar dermal matrices and/or skin grafts (14 cases; 15%) and locoregional flaps (8 cases; 8.3%). At follow up, 13 cases (14%) had functional complications relating to their iGAS episode, including neuropathic pain and limited movement. Mortality was 5.2% (5 patients) within the index admission and 7.3% (7 patients) within 90 days. Diabetes was significantly associated with 90-day mortality (p = 0.023; odds ratio [OR] 7.05, 95% confidence interval [CI] 1.41–35.00) and amputation (p = 0.033; OR 4.51, 95% CI 1.19–17.19). Other systemic comorbidities were not significantly associated with mortality or amputation. Soft tissue iGAS infections principally affect the limbs and require multimodal management to mitigate the high rates of infection-related morbidity and mortality. Diabetes is significantly associated with higher amputation and mortality rates in our study population. Appropriate services should be in place to manage long-term functional disability and mental health morbidity after iGAS.