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.