You write:….In such places, nurses and even untrained lay carers can treat patients with maggot therapy… […] Though the application of maggots (and perhaps also their removal from the wound) could be done by more or less everybody, I think that it should be very clearly said that everything should be done under the supervision and responsibility of a physician. He/she should more or less know how to apply, how many maggots to use, how long to leave on the wound, when to remove, what to do during those 2-3 days of a treatment cycle, when to debride the large necrotic parts of wound, and what to do when any complication appears (e.g., pain). I would suggest that you use the words “apply maggots” than “treat patients”
In an ideal world there would be trained doctors, surgeons, and nurses familiar with maggot therapy. However, this is the real world and if communities want to try maggot therapy, they must grow their own medicinal maggots, and without trained doctors, lay carers have to treat patients with chronic or infected wounds. The sad reality is that in many parts of the world there is a terrible shortage of doctors and nurses. Where there are no doctors and nurses it is up to family carers and community nurses to look after the ill. Our research and development project sought to bring hope to exactly these isolated and abandoned populations. We needed to develop instructional resources that make it easy for lay persons to produce safe medicinal maggots and treat patients. We believe that our instructions, if studied carefully, provide the necessary information in a format that is accessible to lay persons and community nurses.
You write:…Patients must not immerse dressings. Maggots will drown… We also ask the patients and the health care providers not to wet the dressing in order not to stop the drainage of the liquids produced by the wound and the maggots, however biologically I can imagine that it will be very difficult to drown maggots in water. I did an experiment with body lice and they survived at least 15 hrs. under water!! Maggots should do it even better!.
You are correct in suspecting that maggots can survive and even thrive in liquids for some time and even longer when they can breathe via their breathing organs (spiracles) at the end of their body from time to time. However, prolonged inundation in liquids leads to a lack of oxygen. Insects are quite tolerant of temporary oxygen shortage and researchers exploit this when they anaesthetize flies with CO2. After a while, when the flies are returned to oxygen-rich air, they wake up and go about their business as usual. The same is true for maggots. When submersed for a while in water they slow down and may even become immobile but when removed from the water they regain their former activity level. Therefore, it stands to reason that, even though maggots can survive temporary submersion in water, their reduced activity will most likely impact treatment and efficacy.
Again, it is important that our instructions are easily understood by people with no prior experience in entomology. The idea that drowning is detrimental to a maggot can be easily understood without the need to discuss the respiratory physiology of the animal.
You write: …Apply medicinal maggots at a dose of 5-10 per cm2 to the wound… Although I see this number in several publications, we know that perhaps this is true for an superficial wound but these number of maggots will do little in a deep wound with a lot of sloughy and necrotic tissue.
This makes sense. A wound that is deep and uneven in its three-dimensional shape has a greater surface area and therefore requires more maggots for complete debridement. Even in such cases, the recommended 5-10 maggots per cm2 are likely to deliver some therapeutic benefit with carers and patients seeing progress. Elsewhere in the guidance material, we recommend repeat treatment if too few maggots have been applied for some reason.
You write:…Remove bagged maggots after 3-4 days… Perhaps it should be added that the bagged maggots should be placed each time in the areas which need debridement, as they do not have the possibility to move around as the free-range ones. It is possible that those biobags are displaced during the 3-4 days of treatment and should be brought to the “right” places.
This is a helpful suggestion and we will provide this advice in our next edition of the Treatment Manual. In the meantime, we trust that carers notice where the biobag has achieved debridement and depend on their common sense to place the next round of biobags (if a repeat is required) directly onto areas of the wound that require further debridement.
You write: …Remove maggots after 2-3 days…As you know, there are many disadvantages in leaving maggots for long periods of time on the wound. It is possible that the maggots debrided the area after e.g., one day and [leaving] them on the wound will only cause additional pain and maceration of the wound. It is also possible that the adhesive bands which are used for the cage-like dressing become loose and maggots start escaping. Though it is more time consuming we are using whenever possible a 24-hour maggot cycle.
We were careful to provide treatment advice that is based on published nursing guidelines and the literature. Your advice to reduce the time for each treatment cycle to one day has some merit. A more nuanced recommendation around treatment length may be required in the next version of the manual. In the meantime, we regard the potential risk as minimal in low-resource and austere healthcare settings. There is always the risk of escaping maggots from failing free-range dressings and carers will in time learn to improve and monitor the dressing to avoid escapes.
Though the Zink crème is a good solution to protect the skin around the wound, we are placing the adhesive bands in a way that only the wound is exposed to the maggots
This is a good suggestion. We have based our treatment advice on published best-practice treatment guidelines for free-range treatment, which include protection of exposed skin around the wound with Zink crème. Personal communication with some practitioners suggested that skin protection may even be optional for the brief period of maggot therapy. A slight irritation of the surrounding skin from larval activity may be acceptable. Our treatment video demonstrations were also limited by the fake wound makeup (maulage) which prevented us from sticking the hydrocolloid barrier too close to the wound edge.