tangent
11-28-01, 21:44
Maggot therapy for the treatment of wounds is also called maggot
debridement therapy, MDT, larval therapy, and biosurgery.
Modern maggot therapy is generally considered to have been
pioneered by Dr. W. S. Baer in the 1930's.
Dr. Baer discovered the hard way that it is advisable to use
sterile (in the bacterioloical sense) maggots - he suffered a 75%
mortality rate on one occasion when using nonsterile maggots.
Fortunately sterile maggots are easy to produce - you start with
eggs, immerse them in a stterilant, then raise the maggots on
sterile food; their eggs should produce sterile maggots. A
variety of materials are used for the initial sterilization; I
would suggest reading the references for the details.
There is a survival variation of maggot therapy that is contained
in the special forces medical manual; it is appended as well.
This method skips the sterilization step. However, if you have
any choice whatsoever, do not, repeat not, use nonsterile maggots.
The odds of developing something like tetanus from using nonsterile
maggots are definitely not in your favor.
The sterile larvae are introduced into the wound. Dr. Baer used
a significant number in his treatment of chronic osteomyelitis,
sometimes up to several hundred. Modern recommendations are to
use a maximum of 10 larvae/cm2 wound area; fewer should be used
when little necrotic tissue is present (5-8 are more common
numbers). The wound is covered with a gauze dressing, taped if
possible to prevent the escape of the larvae. After 1-3 days, the
larvae are washed out of the wound by rinsing with sterile saline
or water; more larvae are introduced if needed until the wound is
clean (the period is based on how long it takes the larvae to
turn into flies - it is desirable to remove them before this
occurs.)
The dressing can be simple gauze pads layered or taped to keep
the larva in. If suitable supplies are available, Dr. R. A.
Sherman has designed a two-layered dressing comprising a bottom
layer formed from a hydrocolloid pad covered with a fine chiffon
or nylon mesh above which a top layer of gauze is placed (and
from which location it can be easily removed and replaced) to
absorb liquids draining from the wound (see selected
references).
All maggots are not equal - some will eat living tissue.
You should select larva which only eat dead tissue, if
possible.
Larva of the following species are recognized as useful:
Lucilia illustris
Phaenicia sericata (green blow fly)
Phormia regina (black blow fly)
Appendix 1
Selected References
Baer, W.S. "The treatment of chronic osteomyelitis with the
maggot (larvae of the blowfly)," Journal of Bone and Joint
Surgery. 13:438, 1931.
LeClerq, M. "Utilisation de larves de Dipteres - maggot therapy
- en medicine: historique et actualite," Bull. Annls. Soc. belge
Ent. 126: 41-50, 1990.[French]
Pechter, E.A., and Sherman, R.A. "Maggot therapy: The Medical
Metamorphosis." Plastic and Reconstructive Surgery.
72(4):567-570. 1983.
Sherman, R.A., and Wyle, F.A. "Low cost, low maintenance rearing
of maggot in hospitals, clinics and schools," Journal of the
American Society of Tropical Medicine and Hygiene.
54(1):38-41. 1996.
Sherman R.A. "A new dressing design for use with maggot
therapy," Plastic and Reconstructive Surgery. 100:451-456.
1997.
WWW Resources
The Biosurgical Research Unit:
http://www.smtl.co.uk/WMPRC/BioSurgery/index.html
Maggot Therapy Project
http://www.ucihs.uci.edu/path/sherman/home_pg.htm
Appendix 2
ST-31-91B
US ARMY SPECIAL FORCES MEDICAL HANDBOOK
SEPTEMBER 1982
CHAPTER 22 PRIMITIVE MEDICINE
22-3 MAGGOT THERAPY FOR WOUND DEBRIDEMENT
a. Introducing maggots into a wound can be hazardous because the
wound must be exposed to flies. Flies, because of their filthy
habits, are likely to introduce bacteria into the wound, causing
additional complications. Maggots will also invade live healthy
tissue when the dead tissue is gone or not readily available.
Maggot invasion of healthy tissue causes extreme pain and
hemmorrhage, possibly enough to be fatal.
b. Dispite the hazards involved , maggot therapy should be
concidered a viable alternative when, in the absence of
antibiotics, a wound becomes severely infected, does not heal,
and ordinary debridement is impossible.
(1) All bandages should be removed so that the wound is
exposed to circulating flies. Flies are attracted to foul or
fetid odors coming from the infected wound; they will not deposit
eggs on fresh clean wounds.
(2) In order to limit further contamination of the wound
by disease organisms carried by the flies, those flies attracted
to the wound should not be permitted to lite directly on the
wound surface. Instead, their activity should be restricted to
the intact skin surface along the edge of the wound. Live
maggots deposited here and/or maggots hatching from eggs
deposited here will find their way into the wound with less
additional contamination than if the flies were allowed free
access to the wound.
(3) One exposure to the flies is usually all that is
necessary to ensure more than enough maggots for thorough
debridement of a wound. Therefore, after the flies have
deposited eggs the wound should be covered with a bandage.
(4) The bandage should be removed daily to check for
maggots. If no maggots are observed in the wound within 2 days
after exposure to the flies, the bandage should be removed and
the wound should be re-exposed. if the wound is found to be
teeming with maggots when the bandage is removed as many as
possible should be removed using forceps or some other sterilized
instrument or by flushing with sterile water. Only 50 - 100
maggots should remain in the wound.
(5) Once the maggots have become established in the
wound, it should be covered with a bandage again, but the maggot
activity should be monitored closely each day. A frothy fluid
produced by the maggots will make it difficult to see them. This
fluid should be "sponged out" of the wound with an absorbant
cloth so that all of the maggots in the wound can be seen. Care
should be taken not to remove the maggots with the fluid.
(6) The period of time necessary for maggot debridement
of a wound depends on a number of factors, including the depth
and extent of the wound, the part of the body affected, the
number of maggots present in the wound, and the fly species
involved. In a survival situation an individual will be able to
control only one of these factors-- the number, and sometimes not
even that; therefore the exact time to remove the maggots cannot
be given in specific numbers of hours or days. However it can be
said with certainty that the maggots should be removed
immediately once they have removed all the dead tissue and before
they have become established in healthy tissue. When the maggots
begin feeding on normal healthy tissue, the individual will
experience an increased level of pain at the site of the wound as
the maggots come in contact with "live" nerves. Bright red blood
in the wound also indicates that the maggots have reached healthy
tissue.
(7) The maggots should be removed by flushing the wound
repeatedly with sterile water. When all the maggots have been
removed, the wound should be bandaged. To ensure that the wound
is free of maggots, check it every four hours or more often for
several days. Any remaining
22-4
maggots should be removed with sterilized forceps or by
flushing with sterile water.
(8) Once all of the maggots have been removed, bandage
the wound and treat it as any other wound. It should heal
normally provided there are no further complications
~
Stanley Roberts
As I said:
...if you have
any choice whatsoever, do not, repeat not, use nonsterile maggots.
> Let the flies lay eggs and
> let them eat. The military is of the opinion that maggots will not eat
> living tissue.
No, they are not. I provided the full text of the survival version
of MDT as an appendix to my message. I direct your attention
to paragraph 6 of these instructions. If you are lucky, you
will get maggots that only eat dead tissue (some of the good species
are identified in my original post on this topic); however, the majority
of maggots will do both, and some prefer living tissue.
> Once the dead or infected material has been eaten they
> will crawl out looking for more. What the heck, if the soldier is going
> to die anyway, give him a chance to live by this method.
>
That is the idea - the use of nonsterile nonselected maggots is
a last resort procedure.
debridement therapy, MDT, larval therapy, and biosurgery.
Modern maggot therapy is generally considered to have been
pioneered by Dr. W. S. Baer in the 1930's.
Dr. Baer discovered the hard way that it is advisable to use
sterile (in the bacterioloical sense) maggots - he suffered a 75%
mortality rate on one occasion when using nonsterile maggots.
Fortunately sterile maggots are easy to produce - you start with
eggs, immerse them in a stterilant, then raise the maggots on
sterile food; their eggs should produce sterile maggots. A
variety of materials are used for the initial sterilization; I
would suggest reading the references for the details.
There is a survival variation of maggot therapy that is contained
in the special forces medical manual; it is appended as well.
This method skips the sterilization step. However, if you have
any choice whatsoever, do not, repeat not, use nonsterile maggots.
The odds of developing something like tetanus from using nonsterile
maggots are definitely not in your favor.
The sterile larvae are introduced into the wound. Dr. Baer used
a significant number in his treatment of chronic osteomyelitis,
sometimes up to several hundred. Modern recommendations are to
use a maximum of 10 larvae/cm2 wound area; fewer should be used
when little necrotic tissue is present (5-8 are more common
numbers). The wound is covered with a gauze dressing, taped if
possible to prevent the escape of the larvae. After 1-3 days, the
larvae are washed out of the wound by rinsing with sterile saline
or water; more larvae are introduced if needed until the wound is
clean (the period is based on how long it takes the larvae to
turn into flies - it is desirable to remove them before this
occurs.)
The dressing can be simple gauze pads layered or taped to keep
the larva in. If suitable supplies are available, Dr. R. A.
Sherman has designed a two-layered dressing comprising a bottom
layer formed from a hydrocolloid pad covered with a fine chiffon
or nylon mesh above which a top layer of gauze is placed (and
from which location it can be easily removed and replaced) to
absorb liquids draining from the wound (see selected
references).
All maggots are not equal - some will eat living tissue.
You should select larva which only eat dead tissue, if
possible.
Larva of the following species are recognized as useful:
Lucilia illustris
Phaenicia sericata (green blow fly)
Phormia regina (black blow fly)
Appendix 1
Selected References
Baer, W.S. "The treatment of chronic osteomyelitis with the
maggot (larvae of the blowfly)," Journal of Bone and Joint
Surgery. 13:438, 1931.
LeClerq, M. "Utilisation de larves de Dipteres - maggot therapy
- en medicine: historique et actualite," Bull. Annls. Soc. belge
Ent. 126: 41-50, 1990.[French]
Pechter, E.A., and Sherman, R.A. "Maggot therapy: The Medical
Metamorphosis." Plastic and Reconstructive Surgery.
72(4):567-570. 1983.
Sherman, R.A., and Wyle, F.A. "Low cost, low maintenance rearing
of maggot in hospitals, clinics and schools," Journal of the
American Society of Tropical Medicine and Hygiene.
54(1):38-41. 1996.
Sherman R.A. "A new dressing design for use with maggot
therapy," Plastic and Reconstructive Surgery. 100:451-456.
1997.
WWW Resources
The Biosurgical Research Unit:
http://www.smtl.co.uk/WMPRC/BioSurgery/index.html
Maggot Therapy Project
http://www.ucihs.uci.edu/path/sherman/home_pg.htm
Appendix 2
ST-31-91B
US ARMY SPECIAL FORCES MEDICAL HANDBOOK
SEPTEMBER 1982
CHAPTER 22 PRIMITIVE MEDICINE
22-3 MAGGOT THERAPY FOR WOUND DEBRIDEMENT
a. Introducing maggots into a wound can be hazardous because the
wound must be exposed to flies. Flies, because of their filthy
habits, are likely to introduce bacteria into the wound, causing
additional complications. Maggots will also invade live healthy
tissue when the dead tissue is gone or not readily available.
Maggot invasion of healthy tissue causes extreme pain and
hemmorrhage, possibly enough to be fatal.
b. Dispite the hazards involved , maggot therapy should be
concidered a viable alternative when, in the absence of
antibiotics, a wound becomes severely infected, does not heal,
and ordinary debridement is impossible.
(1) All bandages should be removed so that the wound is
exposed to circulating flies. Flies are attracted to foul or
fetid odors coming from the infected wound; they will not deposit
eggs on fresh clean wounds.
(2) In order to limit further contamination of the wound
by disease organisms carried by the flies, those flies attracted
to the wound should not be permitted to lite directly on the
wound surface. Instead, their activity should be restricted to
the intact skin surface along the edge of the wound. Live
maggots deposited here and/or maggots hatching from eggs
deposited here will find their way into the wound with less
additional contamination than if the flies were allowed free
access to the wound.
(3) One exposure to the flies is usually all that is
necessary to ensure more than enough maggots for thorough
debridement of a wound. Therefore, after the flies have
deposited eggs the wound should be covered with a bandage.
(4) The bandage should be removed daily to check for
maggots. If no maggots are observed in the wound within 2 days
after exposure to the flies, the bandage should be removed and
the wound should be re-exposed. if the wound is found to be
teeming with maggots when the bandage is removed as many as
possible should be removed using forceps or some other sterilized
instrument or by flushing with sterile water. Only 50 - 100
maggots should remain in the wound.
(5) Once the maggots have become established in the
wound, it should be covered with a bandage again, but the maggot
activity should be monitored closely each day. A frothy fluid
produced by the maggots will make it difficult to see them. This
fluid should be "sponged out" of the wound with an absorbant
cloth so that all of the maggots in the wound can be seen. Care
should be taken not to remove the maggots with the fluid.
(6) The period of time necessary for maggot debridement
of a wound depends on a number of factors, including the depth
and extent of the wound, the part of the body affected, the
number of maggots present in the wound, and the fly species
involved. In a survival situation an individual will be able to
control only one of these factors-- the number, and sometimes not
even that; therefore the exact time to remove the maggots cannot
be given in specific numbers of hours or days. However it can be
said with certainty that the maggots should be removed
immediately once they have removed all the dead tissue and before
they have become established in healthy tissue. When the maggots
begin feeding on normal healthy tissue, the individual will
experience an increased level of pain at the site of the wound as
the maggots come in contact with "live" nerves. Bright red blood
in the wound also indicates that the maggots have reached healthy
tissue.
(7) The maggots should be removed by flushing the wound
repeatedly with sterile water. When all the maggots have been
removed, the wound should be bandaged. To ensure that the wound
is free of maggots, check it every four hours or more often for
several days. Any remaining
22-4
maggots should be removed with sterilized forceps or by
flushing with sterile water.
(8) Once all of the maggots have been removed, bandage
the wound and treat it as any other wound. It should heal
normally provided there are no further complications
~
Stanley Roberts
As I said:
...if you have
any choice whatsoever, do not, repeat not, use nonsterile maggots.
> Let the flies lay eggs and
> let them eat. The military is of the opinion that maggots will not eat
> living tissue.
No, they are not. I provided the full text of the survival version
of MDT as an appendix to my message. I direct your attention
to paragraph 6 of these instructions. If you are lucky, you
will get maggots that only eat dead tissue (some of the good species
are identified in my original post on this topic); however, the majority
of maggots will do both, and some prefer living tissue.
> Once the dead or infected material has been eaten they
> will crawl out looking for more. What the heck, if the soldier is going
> to die anyway, give him a chance to live by this method.
>
That is the idea - the use of nonsterile nonselected maggots is
a last resort procedure.