Aeromonas hydrophila infections following use of medicinal leeches in replantation and flap surgery.

Aeromonas hydrophila infections are a recognized complication of postoperative leech application, and can occur with measurable frequency in populations of patients treated with leeches. We review 11 previously reported leech-related Aeromonas infections and analyze seven unreported cases. These infections range from minor wound complications to extensive tissue loss and sepsis. Often, these infections followed leech application to tissue with questionable arterial perfusion. Onset of clinical infection in these patients ranged from within 24 hours of leech application to 10 days or more after leech application. Late infections may represent bacterial invasion from colonized necrotic tissue. Based on these observations, we recommend that leech applications be restricted to tissue with arterial perfusion to minimize contamination of necrotic tissue. We also recommend that patients treated with leeches receive antibiotics effective against Aeromonas hydrophila before leech application. Patients treated with leeches and discharged with eschars or open wounds might benefit from oral antibiotic therapy until wound closure. These precautions may minimize or eliminate this complication of leech use.     

Antibiotic sensitivities of Aeromonas hydrophila cultured from medicinal leeches

Increased use of medicinal leeches (Hirudo medicinalis) for the treatment of venous congestion in flaps and replanted parts has coincided with reports of soft tissue infections following leech application. We cultured the gullets of 20 medicinal leeches to re-examine the antibiotic sensitivities of Aeromonas hydrophila, the leech enteric organism associated with reported infections. These isolates reflected reported resistance to penicillin and first generation cephalosporins as well as sensitivity to gentamicin, tetracycline and chloramphenicol. Additionally, the cultures were sensitive to cefamandol, cefoxitin and two third generation cephalosporins (cefoperazone and cefotaxime). These findings suggest that cefamandol, cefoxitin and some third generation cephalosporins may have a role as perioperative antibiotics in replantation and flap surgery. These antibiotics might provide prophylaxis against Aeromonas hydrophila infection when leech use is required.     

Aeromonas species isolated from medicinal leeches

Aeromonas hydrophila infections are a recognized complication of the use of medicinal leeches. The authors performed an experiment designed to find a safe and practical way to sterilize the leech gut of pathogenic organisms. Leeches were incubated for a 12-hour period in solutions of antibiotic effective against A. hydrophila. The incubations in the antibiotic solutions failed to eradicate pathogenic bacteria from the gut of the leeches. The authors examined cultures of bacteria isolated from the guts of the commonly used Hirudo medicinalis (European leech) and found a wide variety of pathogenic organisms. A. hydrophila is widely believed to be the most common enteric pathogen, but the authors found A. sobria more frequently in their experiment. They also cultured the guts of the leech H. michaelseni recently used clinically in South Africa. A. caviae was the most common pathogen encountered in these leeches. A. caviae and A. sobria cause a spectra of disease similar to A. hydrophila. The authors endorse the current recommendation that all patients who have leech therapy for congested flaps or replants receive broad-spectrum prophylactic antibiotics. This appears to be the safest and simplest way to prevent leech-related infections.     

Sensitivities of Aeromonas hydrophila cultured from medicinal leeches to oral antibiotics

Infections associated with medicinal leech application are caused by Aeromonas hydrophila, an organism that resides in the leech gut. We cultured the intestinal tracts of 25 leeches and evaluated the efficacy of oral antibiotics against Aeromonas hydrophila. Cultures of this organism showed no sensitivity to ampicillin and inconsistent sensitivity to cephalothin (equivalent to cephalexin). The Aeromonas hydrophila cultures did show consistent sensitivity to ciprofloxacin, tetracycline, and trimethoprim-sulfamethoxasole. These three antibiotics should be considered if oral antibiotic coverage is used in association with leech application.     

Acute postoperative infection with Aeromonas hydrophila after using medical leeches for treatment of venous congestion

Introduction

Venous convulsion after reconstructive microsurgery procedures is one major complication a surgeon has to deal with. Today, especially in the field of reconstructive microsurgery, medicinal leech therapy enjoys a renaissance. The potential risks such as infections associated with leech therapy are generally underestimated and not sufficiently discussed in literature.

Method/patients

We present five male patients with an average age of 47 years. All patients suffered from a trauma incident, which had to be treated as an emergency. Three patients showed, postoperatively, a venous congestion after the reconstructive procedures. Another two patients with flap reconstruction and flap training developed venous problems after 12 and 14 days. In all five cases, the indication was given to use medical leeches (Hirudo medicinalis). In all the patients, a local infection of the injured extremity could be regarded after beginning with the leech treatment. The treatment duration with medical leeches for postoperative venous congestion was an average of 6 days.

Results

The reconstructive procedures in all five cases were unfortunately unsuccessful as major local infections were observed. Microbiological analyses showed, in all cases, an infection with Aeromonas hydrophila.

Conclusion

We recommend making a considered indication for leech therapy, to diagnose wound infections early and to think about prophylactic antibiotics in patients with leech application.     

Medicinal leeches and the microsurgeon: a four-year study, clinical series and risk benefit review

Background: There are case reports and small series in the literature relating to the use of medicinal leeches by plastic surgeons; however, larger series from individual units are rare. The aim of this article is to present a comprehensive 4‐year case series of the use of medicinal leeches, discuss the current evidence regarding indications, risks, and benefits and highlight the recent updates regarding leech speciation. Methods: Patients prescribed leeches in a 4‐year period (July 2004–2008) were collated from hospital pharmacy records (N = 35). The number of leeches used, demographic, clinical, and microbiological details were retrospectively analyzed. Results: Thirty‐five patients were treated with leeches. The age range was 2 to 98 years (mean = 49.3). Leeches were most commonly used for venous congestion in pedicled flaps and replantations. Blood transfusions were necessary in 12 cases (34%) [mean = 2.8 units, range 2–5 units]. Our infection rate was 20% (7/35) including five infections with Aeromonas spp. (14.2%). The proportion of patients becoming infected after leech therapy was significantly greater in the group of patients that did not receive prophylactic antibiotic treatment (Fisher's Exact test P = 0.0005). In total, 14 cases (40%) were salvaged in entirety, in 7 cases 80% or more, in 2 cases 50 to 79%, and in 1 case less than 50% of the tissues were salvaged. In 11 cases (31%), the tissues were totally lost. Conclusion: Our study highlights both the benefits and the risks to patients in selected clinical situations and also the potential risks. The routine use of antibiotic prophylaxis is supported. In view of the emerging evidence that Hirudo verbana are now used as standard leech therapy, and the primary pathogen is Aeromonas veronii, until a large prospective multicenter study is published, large series of patients treated with leeches should be reported. © 2011 Wiley‐Liss, Inc. Microsurgery, 2011.     

Bacterial flora of Hirudo medicinalis and their antibiotic sensitivities in the Middle Black Sea Region, Turkey.

The rate of infectious complications of leech therapy is almost 20% because Hirudo medicinalis has endosymbiotic bacteria. The aim of this study was to determine the bacterial flora of H. medicinalis and their antibiotic sensitivities in a region in Turkey. Sixteen adult leeches were collected in Middle Black Sea region, Turkey. They were rubbed onto blood agar plates directly under ether anesthesia to obtain surface cultures. They were then killed to obtain mouth and gut cultures. Culture swabs were applied to blood agar, eosin methylene blue agar, and ampicillin blood agar plates. Gut contents were applied to blood culture medium as well. Bacteria were isolated in 15 of 16 leech surfaces, in 7 of 16 mouths, and in 15 of 16 guts. Isolated bacteria were identified with Analytical Profile Index 32 E and Analytical Profile Index 20 NE (fermentative and nonfermentative respectively). Most common types of cultured bacteria were Aeromonas hydrophila (N = 25), Ochrobacter anthropi (N = 23), nonfermenting Gram-negative rods (N = 12), Acinetobacter lwoffi (N = 3), and A. sobria (N = 2) in 73 isolates. A standard disk diffusion test was performed on isolated bacteria. All isolates were 100% susceptible to ciprofloxacin, cefotaxime, ceftazidime, gentamicin, and trimethoprim/sulfamethoxazole. Because leeches are carriers of Aeromonas and other bacteria, appropriate antibiotic prophylaxis should be administrated to the patient who needs leech therapy. Antibacterial agents can be determined by the resistance pattern of the bacterial flora of regional H. medicinalis.     

Aeromonas hydrophila infection complicating digital replantation and revascularization

Two cases of thumb replantation and one of finger revascularization complicated by Aeromonas hydrophila infection are reported. Two digits were lost because of infection in soft tissue and osteomyelitis. One thumb had extensive necrosis. In all cases the infection was difficult to eradicate, probably because of ischemia. All three patients sustained their injuries while cutting meat or fish. These infection sources have not been previously reported. Note is made of Aeromonas hydrophila in medicinal leeches that are used in microvascular surgery and the potential for iatrogenic infection.     

Leech-borne Serratia marcescens infection following complex hand injury.

Leeches are commonly used in the postoperative course of plastic surgical operations where there is venous congestion in a pedicled or free flap. They provide a temporary relief to venous engorgement whilst venous drainage is re-established. It is known that leeches can carry Aeromonas hydrophila infection, and a second or third generation cephalosporin antibiotic has traditionally been given as prophylaxis against infection. We report a new observation that leeches can carry Serratia marcescens and give rise to clinically significant infection. The implication for prophylaxis and treatment of leech-associated cellulitis is discussed.     

Aeromonas hydrophila wound infection of the hand initially presenting as clostridial myonecrosis

A traumatic hand laceration in a previously health 17-year-old boy resulted in a rapidly progressive palmar space infection, with gas formation, in the soft tissues caused by Aeromonas hydrophila. Typically associated with aquatic injuries, A. hydrophila was not initially suspected since the injury did not occur near water. Physicians treated trauma-related soft tissue infections, particularly when the initial Gram stain shows many polymorphonuclear leukocytes and gram-negative bacilli, must consider the possibility of an Aeromonas infection even if the injury occurred in a nonaquatic environment. Appropriate therapy, including vigorous wound debridement and an aminoglycoside antibiotic, will be curative in an immunologically normal host.     

Hirudo Medicinalis and the plastic surgeon.

Medicinal leech therapy is an ancient craft that dates back to ancient Egypt and the beginnings of civilisation. The popularity of Hirudo Medicinalis has varied throughout history, reaching such a peak in Europe in the early 19th century that supplies were exhausted. During the latter half of the 19th century, their use fell out of favour, as they did not fit in with the emerging concepts of modern medicine. Leeches have enjoyed a renaissance in the world of reconstructive microsurgery during recent years, and their first reported use in alleviating venous engorgement following flap surgery was reported in this journal [M Derganc, F Zdravic, Venous congestion of flaps treated by application of leeches, Br J Plast Surg 13 (1960) 187]. Contemporary plastic and reconstructive surgeons in units throughout the United Kingdom and Ireland continue to use leeches to aid salvage of failing flaps. We carried out a survey of all 62 plastic surgery units in the United Kingdom and the Republic of Ireland to assess the current extent of use, and to investigate current practice. We have shown that the majority of plastic surgery units in the UK and Ireland use leeches post-operatively and that the average number of patients requiring leech therapy was 10 cases per unit per year. Almost all units use antibiotic prophylaxis, but the type of antibiotic and combination used is variable. We outline current practice and suggest a protocol for the use of leeches. Whilst the use of leeches is widespread, the plastic surgery community has progressed little in defining indications for their use or in achieving an accepted protocol for their application in units throughout the UK and Ireland.     

Aeromonas hydrophila upper extremity infection

A severe soft tissue infection of the upper extremity caused by Aeromonas hydrophila followed a water skiing injury in which a tow rope caused degloving of a portion of the skin and severe contusion to underlying muscle. Infection was established within 36 hours of the injury, accompanied by fever, leukocytosis, and a foul odor. Rapid clinical improvement occurred following radical debridement of all nonviable tissue and antibiotic therapy. In cases involving water contamination, Aeromonas hydrophila infection should be suspected with the onset of a rapidly developing infection with a febrile response. Rapid surgical intervention and treatment with an aminoglycoside or a third-generation cephalosporin antibiotic is the treatment of choice.     

Digit replantation applying the leech Hirudo medicinalis

Digits that were formerly assessed as nonreplantable may now be replanted with the help of the leech Hirudo medicinalis. The early experience with a series of patients who had relative contraindications for replantation is reported. In each case, venous repair was either marginal or technically impossible. Postoperative venous congestion developed following replantation and was treated with the application of medicinal leeches. Patient acceptance was high, and no infections developed. No patient required transfusion. The authors conclude that the use of medicinal leeches shows promise as a safe and effective method of providing temporary venous drainage in replanted digits.     

Determining the appropriate number and duration of leech therapy in congested tissues using tissue spectrophotometry and laser Doppler flowmetry

A universal protocol determining the number of leeches and their application time does not exist. The aim of this study, therefore, is to quantify perfusion dynamics in venous congested tissues after leech application to get more detailed information about changes due to leech‐induced skin microcirculation and to evaluate the usability of the Oxygen to See (O2C) device in terms of determining the appropriate number of leeches and the duration of therapy. Twelve patients with the need for leech therapy participated in the study. Perfusion dynamics of the congested tissue was assessed using the O2C device, which determines blood flow (BF), the relative amount of hemoglobin (rHB), and the oxygen saturation (SO2). Measurements were carried out before leech application and on various intervals like 10 minutes, one hour, and three hours after leech application. The leech application effectuated after 10 minutes a nonsignificant perfusion improvement, which further increased after one hour with a significant reduction of the relative amount of hemoglobin and a significant increase of blood flow and oxygen saturation (BF= +56.7%; rHB= ?25.5%; SO2= +53.7%). After three hours, the values returned to the levels before leech administration. In two cases, in which further administration of leeches within the measurement period was necessary, no substantial perfusion changes were obtained. The results of this study forms a more precise pattern of microcirculatory changes of leech therapy in congested tissues. According to our measurements a venous drainage improvement can be expected in congested tissue one hour after leech administration. The O2C seems to be a useful method to determine the appropriate number and duration of leech therapy.     

Parapharyngeal soft-tissue infection with Aeromonas hydrophila.

Parapharyngeal soft tissue infections may be rapidly progressive and life-threatening. Prompt institution of appropriate antimicrobial therapy is of paramount importance. This report highlights the potential virulence of Aeromonas hydrophila in infection of the head and neck and the need to consider this organism in selected patients.     

The role of leech water sampling in choice of prophylactic antibiotics in medical leech therapy

Medical leech therapy (MLT) with Hirudo medicinalis is well established as a treatment for venous congestion of tissue flaps, grafts, and replants. Unfortunately, this treatment is associated with surgical site infections with bacterial species, most commonly Aeromonas hydrophila, which is an obligate symbiot of H. medicinalis. For this reason, prophylactic antibiotics are recommended in the setting of MLT. After culturing Aeromonashydrophila resistant to ciprofloxacin from a tissue specimen from a patient with a failed replant of three digits post‐MLT, we performed environmental surveillance cultures and antibiotic susceptibility testing on water collected from leech tanks. This surveillance was performed twice weekly for 2.5 months. Fourteen surveillance cultures demonstrated 21 isolates of Aeromonas species, 71.4% of which were ciprofloxacin susceptible. All isolates were sulfamethoxazole‐trimethoprim (SXT) susceptible. The prophylactic antibiotic regimen of choice for leech therapy at our institution is SXT, with culture of tank water to refine antimicrobial choice if necessary. This study demonstrates the importance of regular surveillance to detect resistant Aeromonas species in medical leeches; however optimal practice has not been established. © 2013 Wiley Periodicals, Inc. Microsurgery, 2013.     

Delayed leech-borne infection with Aeromonas hydrophilia in escharotic flap wound.

Medicinal leeches (Hirudo medicinalis) are commonly used in plastic surgery for the salvage of congested flaps and replanted parts compromised by venous congestion. Infection associated with leech therapy is a documented complication of leech application, with reported incidences ranging from 2.4 to 20% [De Chalain TM. Exploring the use of the medicinal leech: a clinical risk-benefit analysis. J Reconstr Microsurg 1996;12(3):165-72.1]. We describe a case of delayed leech-borne infection, from the escharotic portion of a latissimus dorsi flap, which developed several days after stopping leech therapy for venous congestion in a reconstructed breast.     

A case of septicaemia due to Aeromonas hydrophila

A case of Aeromonas hydrophila septicaemia is reported, arising from the use of leeches in an attempt to salvage a replanted arm. It is believed that this is the first report of this complication.     

Aeromonas hydrophila water-associated traumatic wound infections: a review

The bacterium Aeromonas hydrophila is commonly found in natural bodies of water, and is a potential invasive pathogen for those who suffer trauma while submerged in water. Five patients treated by the authors and 18 previously reported patients were reviewed to further define the characteristics of A. hydrophila wound infections. Although Aeromonas has been isolated from salt and brackish water, all 23 cases occurred following contact with fresh water. Signs of infection usually appeared 8-48 hours following puncture or laceration injury. The foot or leg were most commonly involved. Infection was frequently rapidly progressive; fascia, tendon, muscle, bone, or joint involvement occurred in 39% of cases. In addition to A. hydrophila, other aerobic and anaerobic bacteria were found in 48% of cases. Aeromonas infection should be suspected in cases of early and rapidly progressive wound infection following trauma in fresh water. Broad-spectrum antimicrobial therapy and appropriate surgical care should be promptly instituted.     

The use of leeches for treatment of venous congestion of the nipple following breast surgery

The medicinal leech,Hirudo medicinalis, played a central role in the evolution of medieval and folk medicine. Today, for the first time in history, the leech actually has a real and valuable purpose in medicine as a useful adjunct for the plastic surgeon: It provides relief of venous congestions. For over 2000 years, leeches were needlessly applied for a multitude of maladies as an adjunct to blood-letting. Their use in Europe peaked between 1830 and 1850, however, shortages led to a subsequent decline in leech application. Today there is a real clinical use for leeches which had led to a resurgence in their use in plastic surgery. Plastic surgeons use leeches in microsurgery to salvage congested flaps, whose viability is uncertain due to venous congestion. We present our experience with two patients where leeches were used to treat isolated venous engorgement of the nipple following breast surgery. Leech therapy is painless, well tolerated, and does not result in significant scarring. Prompt initiation of treatment is mandatory and produces dramatic resolution of venous congestion.