Maggots are the larvae of flies and often infest untreated, open wounds.
The study, one of the first to classify the types of maggots found in hospital infections, found that most infestations were caused by the same noninfectious species of maggots that are used sometimes to treat wounds. In addition, most of the patients studied were infested before admission to the hospital, and many of them were homeless. Unfortunately, when health care professionals clean a wound, they rarely save the maggots for further pathological analysis. Only by analyzing the larvae can we determine whether or not it is invading fresh, healthy tissue or infesting dead, diseased areas of the body. Sherman and colleagues from 20 hospitals nationwide found that in 42 cases of maggot infestation, no fresh tissue invasion occurred because most larvae were those of the green blowfly, which do not invade fresh tissue.