hours of their injuries. 15 Most of the fish species identified were tilapia commonly used in Asian cuisine. 15 The median age of the case-patients was 67 years (range 40-80 years); the female-to-male ratio was 2:1; and all patients were of Asian descent. 15 Four patients had chronic underlying diseases, including diabetes, chronic renal failure, rheumatic heart disease, and osteoarthritis. 15 In all 11 cases, invasive S. iniae infection was culture-confirmed; and S. iniae isolates from nine of these cases were identical by pulsed-field gel electro- phoresis (PFGE) and also matched PFGE-identified S. iniae isolates obtained from the surface and brains of infected tilapia from local aquaculture farms. 15 In all cases, the S. iniae isolates were sensitive to a broad range of antibiotics, including aminoglycosides, cephalosporins, macrolides, penicillins, and trimethoprim-sulfamethoxazole. 15 All pa- tients were admitted to hospitals, treated with parenteral antibiotics, and responded to antibiotic therapy within two to four days. 15 The investigators concluded that most pa- tients had been inoculated with S. iniae in association with minor injuries received during preparation of fresh fish, especially tilapia, and recommended that precautionary measures be taken, especially by immunocompromised elderly patients, when handling whole, uncooked fish to prevent S. iniae infections. 15 GENERAL MANAGEMENT OF MARINE INJURIES Even minor abrasions and lacerations sustained in marine environments should be considered potentially contaminatedwith commonmarinemicrobes, such as Vibrio species. Following any specific detoxificationmeasures, such as hot water immersion for stingray injuries or topical acetic acid for fire coral and jellyfish stings, all wounds should be irrigated with a sterile diluent solution, if possible, such as normal saline. Crushed or devitalized tissues should be excised by sharp dissection under local anesthesia or pe- ripheral nerve blocks. Foreign bodies should be removed. Diagnostic imaging is often indicated, especially in punc- ture wounds, to exclude retained foreign bodies. Potential constriction bands, such as bracelets, rings, and watches, should be removed from the injured extremity and base- line extremity circumference measurements taken in the event of swelling from necrotizing fasciitis and compart- ment syndromes. Sequential surgical debridements will be indicated in many cases - in all cases of necrotizing fasciitis - and following fasciotomies for compartment syndromes. Most wounds should be left open or packed open to heal by secondary intention. Delayed primary closures may be indicated for potentially disfiguring facial wounds. Tetanus prophylaxis is indicated for all marine wounds. GENERAL MANAGEMENT OF CONTAMINATED MARINE WOUNDS Grossly contaminated or infected wounds and all puncture wounds should be cultured, and the microbiology
16 Shewanella cases in Martinique and another 239 cases reported in the literature over a 14-year period, 1997-2012, Vignier and co-investigators noted that 79% of patients had predisposing risk factors for Shewanella infections - 53% of patients had a skin or mucosal portal of entry, and 44% of cases reported prior marine exposures. 12 The case fatality rate was 13% in their case series. 12 The diagnosis of Shewanella infections can be established by positive blood or lesion aspirate cultures, but the specia- tion of Shewanella causative strains will require molecular characterization by PCR. 12 Most species are sensitive to a broad range of antibiotics, including aminoglycosides, third-generation cephalosporins, and quinolones. S. algae is resistant to penicillins and first- and second-generation cephalosporins. 11,12 For invasive infections, especially in immunosuppressed patients, most authorities recommend two weeks of intravenous antibiotic therapy with third- generation cephalosporins combined with either aminogly- cosides or quinolones, followed by two to three weeks of oral antibiotic therapy. 11-13 Early surgical consultation is also recommended for drainage of bullous lesions, debridement of ulcers, and monitoring for potential extremity compart- ment syndromes requiring decompressive fasciotomies (Figure 1). Streptococcus iniae Streptococcus iniae, a gram-positive, B-hemolytic streptococcus unassigned to a Lancefield Group, was first identified in 1976 as the cause of subcutaneous abscesses in Amazon freshwater dolphins in US aquariums. 14 Often misidentified as S. viridians , S. iniae has emerged as a major fish pathogen capable of causing epizootic outbreaks of invasive streptococcal disease in farm-raised fish. 15 S. iniae initially colonizes the surface of the fish, causing cellulitis which can be complicated by invasive meningoencephalitis with 30%-50% mortality in affected aquaculture ponds. 15 Commercially devastating outbreaks have now been re- ported worldwide in other farm-raised fresh and saltwater fish species, including coho salmon, rainbow trout, tilapia, and yellowtail. 15 The first human cases of S. iniae invasive infections were reported from the Toronto area in 1996, when a cluster of four cases in patients of Asian descent who had recently pre- pared fresh, whole farm-raised fish was reported to public health authorities. 15 Three of these patients had bacteremic cellulitis of the hands secondary to soft tissue injuries that occurred during the preparation of fresh fish obtained from wet markets; and the fourth patient had S. iniae sepsis with arthritis, meningitis, and endocarditis. 15 During a follow- up, one-year surveillance investigation, Weinstein and col- leagues identified 11 patients with invasive S. iniae infections with cellulitis of the hands in eight cases, endocarditis in one case, and either arthritis or cellulitis in the remaining cases. 15 All of the patients had recently handled live or freshly killed fish, and eight patients suffered percutaneous injuries while preparing the fish and developed cellulitis within 16-24
J La State Med Soc VOL 166 May/June 2014 107
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