Exhaustion of the immune system by Group A Streptococcus necrotizing fasciitis: the occurrence of late secondary infections in a retrospective study

Abstract

BackgroundNecrotizing fasciitis is a potentially lethal condition for which early and adequate treatment with surgical debridement and broad-spectrum intravenous antibiotics are essential for survival. It is hypothesized that Group A Streptococcus (GAS) necrotizing fasciitis causes exhaustion of the immune system, making these patients more susceptible for late secondary infections.MethodsA retrospective study was conducted of all patients with necrotizing fasciitis between 2002 and 2016. Patients with necrotizing fasciitis based on macroscopic findings, positive Gram staining, culture or fresh frozen section of fascia biopsies were included. Patients with necrotizing fasciitis were divided into two groups based on the presence of GAS. Of both groups, clinical course, outcome and occurrence of late secondary infections were analyzed. For the occurrence of secondary infections, pneumonia was chosen as reference for late secondary infections.ResultsEighty-one patients with necrotizing fasciitis were included of which 38 (47%) had GAS necrotizing fasciitis and 43 (53%) had non-GAS necrotizing fasciitis. Patients with GAS necrotizing fasciitis were younger (50 vs. 61 years, p=0.023) and more often classified as ASA I (45% vs. 14%, p=0.002) compared with patients with non-GAS necrotizing fasciitis. In-hospital mortality rate for necrotizing fasciitis was 32%. Patients with comorbidities were more likely to die of necrotizing fasciitis compared with patients without comorbidities (OR 7.41, 95% CI 1.58 to 34.63). Twelve patients (39%) with GAS necrotizing fasciitis developed pneumonia compared with four patients (13%) with non-GAS necrotizing fasciitis (p=0.017; OR 4.42, 95% CI 1.124 to 15.79). Median time from diagnosis to development of pneumonia in patients with GAS necrotizing fasciitis was 10 days (IQR 9).ConclusionPatients with GAS necrotizing fasciitis have an increased risk to develop late secondary infections during initial treatment for necrotizing fasciitis compared with patients with necrotizing fasciitis without involvement of GAS. This suggests exhaustion of the immune system after severe GAS infection.Level of evidenceIII

Time is of the essence when treating necrotizing soft tissue infections: a systematic review and meta-analysis

“…Of all NSTIs, necrotizing fasciitis is the most well known and most common NSTI; other NSTIs are myonecrosis and necrotizing cellulitis [1]. Mortality and amputation rates for NSTI are considered high, with described mortality rates varying between 6 and 33% [2][3][4][5]. Factors such as advanced age, female sex, multiple comorbidities, and sepsis upon presentation have previously been linked to increased mortality rates [2,5,6].…”

“…Mortality and amputation rates for NSTI are considered high, with described mortality rates varying between 6 and 33% [2][3][4][5]. Factors such as advanced age, female sex, multiple comorbidities, and sepsis upon presentation have previously been linked to increased mortality rates [2,5,6]. The bacteria causing NSTI can spread rapidly along the fascial planes; therefore, the saying "time is fascia" seems suitable.…”

Non-necrotizing and necrotizing soft tissue infections in South America: A retrospective cohort study

“…A literature review demonstrated a complication rate of 55–59% in patients [ 1 , 2 , 12 , 13 ], with the same risk factors for mortality: advancing age, multiple comorbidities, sepsis on admission, and signs of circulatory shock [ 1 , 36 , 37 ]. The percentage of complications in our study was in agreement with that in the literature, as was our mortality rate of 21.3%.…”

Necrotizing Soft Tissue Infections, the Challenge Remains

“…Type I is polymicrobial and generally consists of various species of gram-positive cocci, gram-negative rods and anaerobes (2,10). Type II is monomicrobial with GAS being the most common microbe found (39,42). Recently an attempt was made to categorize specific strains of bacteria in their presentation, as Type III consists of more rare isolated 3) symptoms upon presentation.…”

“…Studies were identified using the articles previously screened for our own meta-analysis ( 9) and was updated using the same search strategy, furthermore studies were identified from two previous systematic reviews on NSTIs. (39,43,44). Systemic toxicity of polymicrobial infections is most commonly dependent on the mechanism of microbial synergy and not necessarily on toxins.…”