What is the optimal treatment time for larval therapy? A study on incubation time and tissue debridement by bagged maggots of the greenbottle fly, Lucilia sericata

Abstract

The effective use of larvae of the greenbottle fly, Lucilia sericata, in wound debridement requires a working knowledge of how feeding changes over time. Using a laboratory assay and bagged larval dressings, the effect of incubation time on larval feeding rates and body mass was investigated for up to 120 hours at 32°C. The mass of tissue digested increased significantly in incremental 24‐hour periods up to 72 hours, with no significant consumption occurring afterwards. Larval mass increased only up to 48 hours. A further test comparing the efficacy of a single 96‐hour application of larvae against two consecutive 48‐hour applications found that the mass of tissue digested in the latter was 14.3% higher than the former, a difference that was statistically significant. Current clinical guidance suggests a 4‐day application period for bagged larvae. Based on these results, an incubation time of 72 hours (3 days) for bagged larvae would be the most effective at the study temperature. However, it is acknowledged that wound temperature can vary, whereby feeding rates would likely differ. In view of this, we conclude that a period of 3 to 4 days is optimum for the application of larvae, and current guidelines should be adhered to.

The maggot therapy supply chain: a review of the literature and practice

“…There is also solid research and experiential evidence from practitioners and the industry which suggest that the ideal dosage of maggots is in the order of four to eight larvae per cm 2 of wound applied for 48–72 h depending on progress and application technology (Wilson et al ., , ), with each maggot removing approximately 25 mg of dead tissue per day (Mumcuoglu et al ., ). Maggot therapy can be repeated multiple times if necessary.…”

A molecular approach to maggot debridement therapy with Lucilia sericata and its excretions/secretions in wound healing

“…For this reason, the recommended number of maggots varies between 4-10 larvae/cm 2 according to practitioners and experimental studies. 38,44,55,[82][83][84] While the number of larvae recommended for the application is variable, the recommended application times are also variable. Although commercial sources or literature data indicate that 2-5 days of treatment (average duration 3 days) is ideal for larval application, larvae change every 2-3 days is necessary as the larvae will turn into pupa after a certain period of time and will not be suitable for debridement treatment.…”

“…The treatment is continued until there is no necrotic tissue left in the wound and healthy granulation tissue is formed. 2,16,38,43,44,53,55,82,83,85,[86][87][88][89] If the larvae are left in the wound for more than 24 hours, the absorbent dressing layer should be changed frequently. If the Biobag method is preferred, it should be kept on the wound for 2-3 days, but the absorbent dressing layer should be changed once a day.…”

Actualización Sobre Terapia Larval en Heridas

“…Sin embargo, se reconoce que la temperatura de la herida puede variar, por lo que las tasas de alimentación probablemente diferirían. En vista de esto, los autores sugieren que un período de 3 a 4 días es el óptimo para la aplicación de larvas (9). En el estudio de Dallavecchia DL et al, realizado en 2019 en Portugal, se expone que la terapia de desbridamiento de gusanos es segura cuando las larvas se originan en reservas de huevos de laboratorio que han sido esterilizados.…”