The antimicrobial activity of maggots: in-vivo results

In the literature maggot therapy is discussed as a promising and potent form of debridement therapy. The number of maggots needed to debride a wound is estimated at 10 per cm2, and more in case of a higher percentage of necrosis or slough. In the authors' hospital, from March 1999 to May 2002, 16 patients were successfully treated with maggot therapy. The average maggot treatment time was 27 days, with an average of seven maggot changes. Most patients were treated for osteomyelitis, with trauma being the leading aetiological factor. In accordance with in-vitro findings, maggot therapy was found to be more effective in gram-positive infected wounds. Gram-negative bacteria are cultured more often after maggot treatment than before it (p=0.001). The opposite effect was found for gram-positive infected wounds (non-significant p=0.07). In vivo maggots seem to be less effective against gram-negative infected wounds. The authors believe that a higher number of maggots is needed not only for a larger wound or a wound with a higher percentage covered with slough, but also for a wound infected with gram-negative bacteria.