Lower extremity infections by vibrio vulnificus

Introduction
Foot injuries associated with fish bones and fin spines are not common but can cause high morbidity. This is because such injuries often are underestimated or leave residual fragments of foreign matter in the soft tissues, leading to secondary infections. Clinical symptoms depends on fish pathogen organism and varies from local infection to systemic illness or fatal multisystem disease.
Many fish pathogens have been reported to cause these conditions, especially hand infections after handling fishes. Some of them pathogens include: Vibrio vulnificus, Mycobacterium marinum, Streptococcus iniae, Aeromonas hydrophila, Enterobacter, Pseudomonas, Citrobacter frenduii (1, 2).
The common fishes which are responsible for transmission of such infections include: catfish, lionfish, St. Peters fish, cyprinus carpio, amazon dolphin, coho salmon, rainbowtrout and yellowtail (1).
Herein we report our experience of management of four complicated cases, due to fish bone injury, with a follow up of 3-6 years (mean time 4.2 years).

Methods
This is a prospective study of all cases of Vibrio Vulnificus infection presenting at our departments between June 1997 and July 2003.
In this period, nine cases of lower extremity infection by Vibrio Vulnificus during fish injury, were treated in our Departments. The age of the patients ranged from 18 to 78 years and there were 7 males and 2 females. All patients except five, had underlying disease.
Herein we emphasized on complications due Vibrio Vulnificus wound infection, analyzing age, sex, predisposing factors, symptoms, laboratory tests, X-rays, operative culture findings, morbidity and mortality after a 4.2 year of follow-up.

Results
Five patients had only slight symptoms on their admission and they were treated succesfully with oral antibiotics (amoxycillin + clavulanic acid 1g x 2 and clindamycin 300 mg x 3, for seven days) and local wound care (with povidone iodine once a day), after wound culture and antibiogram.
Four patients who presented with excessive swelling of their foot, local tenderness , severe pain at the site of injury, fever (range 38.2-39.2), chills, and malaise, finally they were hospitalized (fig. 1, 2).
Plain X-rays of the foot didn't show any radio-opaque foreign body in any case.
WBC levels, in complicated four cases, were elevated over 14000/mm3. Also CRP and ESR levels were elevated over 16 mg/l and 68 mm/h in the same patients.
Urgent leg amputation was performed in three cases because of irreversible necrotic changes with septic complications and failure of insicional drainage to control the infection. Necrotic soft tissue excision was performed in the other one case and the wound was left open, until healing.
Wound cultures on Gram-stained smears and on Columbia agar with 5% sheep blood, isolated Vibrio Vulnificus in all cases. Blood cultures (by Bactec 9240 instrument) revealed Vibrio Vulnificus in three cases. Features of the four patients are shown at table 1.
The postoperative course was uncomplicated only for one patient. Unfortunately there was one early and one late death. Furthermore one patient who sustained only excision of necrotic soft tissue, presented with calcaneous osteomyelitis caused by Vibrio Vulnificus, three years after the initial fish bone injury (fig. 3).

Discussion
Vibrio vulnificus is a gram negative bacterium, which is found in seawater and shellfish during warm months (3). Both increased temperature of water, approximately over 27ºC and increased salinity usually in fish industries water, provide a suitable enviroment for Vibrio vulnificus (1). It has been suggested that bad store conditions in fish markets such as not packaging the fish in ice and handling of fresh fish by untrained individuals associated with increased risk of infection (4).
As a human pathogen microorganism, producing potentially high morbitity infections either by direct contact of wound with seawater, a fish fin injury, or rarely by ingestion (5). Ussually the infection occurs within 1-2 days and is self-limiting with no significant consequences. Otherwise such infections may lead to septicemia or to cellulitis, necrotizing fasciitis, vesicles, bullae, myositis and finally to limb amputation especially in immunocompromised patients or in patients with liver diseases (2). Extracellural enzymes like hyaluronidase, mucinase, and DNAase, producing by Vibrio species are responsible for the aggressive inflammatory complications (2).
Three patients who were treated at the authors' institutions for soft tissue Vibrio vulnificus infections of the lower extremities, underwent leg amputation. The infection occurred after penetrating injury of the lower extremities by spines of various fish. In three patients the injuries were incurred by spines of Drakaina fish and in one case by Cyprinus caprio fish. The first one is a common fish in Greece area, but the last one is a consumed fish, imported from other Mediterranean countries. Extensive soft tissue necrosis and amputation was performed in three cases, because of aggressive gas gangrene or septic complications. Although blood cultures were positive in all cases, no reccurent infection was detected after 3-6 years of follow up except in one patient. Unfortunatelly a reccurent inflammatory process with concomitant calcaneous osteo-myelitis was developed three years after the initial injury, in this case.
Previous studies have reported mortality rates of more than 25% in patients with Vibrio wound infection and secondary septicemia (5, 6). But others have mentioned good results after appropriate management without limb amputation (7).
Amoxycillin-clavulanate, third generation cephalosporins and tetracyclines are effective against the Vibrio vulnificus bacteria (8). In order to avoid fatal complications, early intravenous antibiotics and appropriate surgical debridement or amputation of the involved area, are required.
Clinicians must maintain a high index of suspicion especially in regions endemic for vibrio necrotising fasciitis and antibiotic prophylaxis must be given to swimmers before or during bathing. In addition soft tissue injury by fish bones must not be underestimated and early aggressive management is demanded.

References
1. Calif, E., Pick, N., Dreyfuss, U., Stahl, S. - Upper extremity infections following common carp fish (Cyprinus Caprio) handling. Journal of Hand Surgery (British and European volume), 2002, 27:78.
2. Said, R., Volpin, G., Grimbeg, B., Friedenstrom, R., Lefler, E., Stahl, S. - Hand infections due to non-cholera vibrio after injuries from St Peter's fish (Tilapia Zilii). Journal of Hand Surgery, (British and European volume), 1998, 23:808.
3. Tilton, R., Ryan, R. - Clinical and ecological characteristics of Vibrio vulnificus in the northeastern United States. Diagn. Microbiol. Infect. Dis., 1987, 6:109.
4. Bisharat, N., Raz, R. - Vibrio infection in Israel due to changes in fish marketing. Lancet, 1996, 348:1585.
5. Klontz, K., Lieb, S., Schreiber, M., Janowski, H., Baldy, L., Gunn, R. - Syndromes of Vibrio vulnificus infections. Clinical and epidemiologic features in Florida cases, 1981-1987. Ann. Intern. Med., 1988, 109:318.
6. Hlady, W.G., Klontz, K.C. - The epidemiology of Vibrio infections in Florida. 1981-1993. J. Infect. Dis., 1996, 173:1176.
7. Calif, E., Kaufman, B., Stahl, S. - Vibrio Vulnificus Infection of the Lower Limb After Fish Spine Injuries. Clin. Orthop. Rel. Res., 2003, 411:273.
8. Fang, F. - Use of tetracycline for treatment of Vibrio vulnificus infection. Clin. Infect. Dis., 1992, 15:1071.

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