Medicinal leech therapy and Aeromonas spp. infection
Research article published in European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology (2016)
Abstract
While the use of medicinal leech therapy (MLT) in reconstructive and orthopaedic surgery is widely described, post-operative complications related to leeches remain a major concern. Aeromonas spp. strains are involved in the majority of reported cases. As surgical success rate is directly impacted, an adapted antibiotic prophylaxis should be instituted in order to minimize these complications. We assessed pharmaceutical process, microbiological control and related infections in order to provide data and choose the appropriate antibiotherapy for patients requiring MLT. We report a clinical and microbiological study over a 24-month period. Clinical data were collected from patients' database, and microbiological analysis both on leeches' tank water and crushed leeches were performed to characterize isolated strains and their susceptibility to antibiotics. A total of 595 leeches were used to treat 28 patients (12 in plastic surgery and 16 in orthopaedic surgery), and three documented cases of post-operative infections were reported. Aeromonas spp. isolates yielded from 62 % of analyzed batches (75 % of Aeromonas veronii). Eighteen Aeromonas spp. isolates yielded from 23 water samples and three crushed leeches. Isolates were similar in tank and crushed leeches. Strains were susceptible to fluoroquinolones, sulfamethoxazole/trimethoprim, aminosides, and third-generation cephalosporins but resistant to amoxicillin/clavulanic acid and second-generation cephalosporins. According to collected data, routine tank water microbiological analyses are mandatory in order to identify leeches' batches containing resistant strains and to discard them. In this context, the surgeon is able to select an appropriated antibiotic prophylaxis in order to avoid MLT associated serious post-operative complications.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Summary
While the use of medicinal leech therapy (MLT) in reconstructive and orthopaedic surgery is widely described, post-operative complications related to leeches remain a major concern.
Why This Matters for Hirudotherapy
This 24-month clinical and microbiological study examined infectious complications of medicinal leech therapy (MLT), analyzing 595 leeches used in 28 plastic and orthopaedic surgery patients alongside cultures of tank water and crushed leeches. Aeromonas spp. (predominantly A. veronii) were recovered from 62% of leech batches, with isolates demonstrating resistance to amoxicillin/clavulanic acid and second-generation cephalosporins but susceptibility to fluoroquinolones, sulfamethoxazole/trimethoprim, aminosides, and third-generation cephalosporins. The work is directly relevant to hirudotherapy safety, supporting routine tank water microbiological surveillance and informed antibiotic prophylaxis to reduce serious post-operative infections. However, the abstract does not specify whether data derive from one or multiple centers, the patient cohort is modest, and the study addresses infection risk management rather than the efficacy of leech therapy itself.
Citation
Medicinal leech therapy and Aeromonas spp. infection.
Verriere B et al. · European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology, 2016
Added to ASH library: March 18, 2026 · Site last updated: June 18, 2026