Independent Predictors of Mortality for Aeromonas Necrotizing Fasciitis of Limbs: An 18-year Retrospective Study

Abstract

Necrotizing fasciitis (NF) of the limbs caused by Aeromonas species is an extremely rare and lifethreatening skin and soft tissue infection. The purpose of this study was to evaluate the specific characteristics and the independent predictors of mortality in patients with Aeromonas NF. Sixty-eight patients were retrospectively reviewed over an 18-year period. Differences in mortality, demographics data, comorbidities, symptoms and signs, laboratory findings, microbiological analysis, empiric antibiotics treatment and clinical outcomes were compared between the non-survival and the survival groups. Twenty patients died with the mortality rate of 29.4%. The non-survival group revealed significant differences in bacteremia, monomicrobial infection, cephalosporins resistance, initial ineffective empiric antibiotics usage, chronic kidney disease, chronic hepatic dysfunction, tachypnea, shock, hemorrhagic bullae, skin necrosis, leukopenia, band polymorphonuclear neutrophils >10%, anemia, and thrombocytopenia. The multivariate analysis identified four variables predicting mortality: bloodstream infection, shock, skin necrosis, and initial ineffective empirical antimicrobial usage against Aeromonas. NF caused by Aeromonas spp. revealed high mortality rates, even through aggressive surgical debridement and antibacterial therapies. Identifying those independent predictors, such as bacteremia, shock, progressive skin necrosis, monomicrobial infection, and application of the effective antimicrobial agents against Aeromonas under the supervision of infectious doctors, may improve clinical outcomes. Necrotizing fasciitis (NF) is a rare and life-threatening necrotizing soft tissue infection (NSSTI) characterized by a rapid bacterial spread with soft tissue necrosis in the subcutaneous layers, particularly within superficial and deep fascia, with overall mortality rates of 12.1-76% 1-8. Early fasciotomy, an appropriate empiric antimicrobial therapy supported by physicians specialized in infectious disease, and aggressive intensive unit care should be initially administered in critically ill patients suffering from fulminant NF to prevent limb loss and possible death 9-11. Our hospital is situated on the western coast of southern Taiwan, and most residents are exposed to occupations related to seawater, raw seafood, fresh or brackish water, and soil. As a result, Vibrio spp. and Aeromonas spp. infections have been reported at a relatively high incidence since 2004 in our hospital 9,12-19. Thus, we set up the team "Vibrio NSSTIs Treatment and Research (VTR) Group", which consists of professional staff working in various departments, including emergency medicine, orthopedic surgery, infectious diseases, intensive care unit (ICU), and hyperbaric oxygen treatment center. Our team has successfully decreased the mortality rate of Vibrio NF from 35% to 13% 8,12. Although we have established a treatment strategy including emergency fasciotomy or amputation, antibiotic therapy with a third-generation cephalosporin plus tetracycline, and a...

Expansion of Necrosis Depending on Hybrid Motor-Driven Motility of Aeromonas hydrophila in a Murine Wound Infection Model

“…A. hydrophila rapidly proliferates in mammalian hosts and then causes fulminant diseases such as NF and bacteremia within a short time period [ 7 , 8 , 9 , 10 , 13 , 14 ]. To determine the effect of motility on the proliferation of A. hydrophila in a murine wound infection model, we collected bacteria from muscles and spleen at 6 h and 12 h after infection with A. hydrophila RIMD111065 WT and non-motile strain Δ motAB / pomAB .…”

“…NF caused by A. hydrophila progresses rapidly within a short time period [ 7 , 8 , 9 , 10 ]. This makes it difficult to treat patients and leads to significant sequelae or fatal outcomes.…”

“…It is pathogenic to fishes, amphibians, reptiles, and mammals [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Wound infection of A. hydrophila in humans is second most frequent after oral infection and associated with traumatic events and burns and scalds related to water and soil [ 1 , 2 , 3 , 9 ]. Most cases of A. hydrophila wound infection occur in healthy people [ 1 , 10 ].…”

“…The wound infections due to A. hydrophila can progress to necrotizing soft tissue infection (NSTI) [ 7 , 8 ]. Necrotizing fasciitis (NF) is the most serious presentation of NSTI, an aggressive subcutaneous infection that spreads along the superficial fascia, which comprises the skin and underlying muscles, and its rapid dissemination can result in more severe disease manifestations such as sepsis [ 8 , 9 , 10 , 13 , 14 ].…”

Taxonomy, virulence determinants and antimicrobial susceptibility of Aeromonas spp. isolated from bacteremia in southeastern China

“…Moreover, according to similar clinical manifestations, Aeromonas infections often be misdiagnosed as Vibrio infections before microbiology identi cation by laboratory, which may lead to improperly use of antimicrobials and ineffective treatment [10]. Aeromonas infections are reported to be prevalent in regions with a high prevalence of chronic hepatitis and warm climate, like Taiwan, which is regarded as one of the endemic areas [11]. However, in mainland China, the incidence of Aeromonas bacteremia in human beings remains to be elucidated.…”