1. Myiasis: Nursing InterventionMyiasis: Nursing Intervention
By: Bridgette C. Williams, BSN, RNBy: Bridgette C. Williams, BSN, RN
SUNY Institute of TechnologySUNY Institute of Technology
2. Lesson Plan: Myiasis
• Topic: Myiasis (maggot infestation for nurse clinicians and educators)
• Prerequisites: Undergraduate nursing degree
• Objective: Differentiate types of myiasis in context of the nursing process
• Rationale: Myiasis is an occurrence in the health care setting
• Part I: Classification—types of myiasis infestation
• Part II: Fly Life Cycle—development from egg to fly
• Part III: Signs & Symptoms—signs of maggot infestation
• Part IV: Nursing Interventions—protocol for maggot removal
• Part V: Conclusion
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3. Presentation Objectives
• At the end of this presentation learners will be able to:
– Define myiasis.
– Identify one myiasis classification.
– Describe at least 2 signs of infestation.
– Explain at least 2 stages of the fly reproductive life cycle.
– Differentiate at least 2 risk factors.
– Apply at least 2 nursing interventions to care plan for myiasis.
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5. Definition
• Myiasis (sounds like my-eye-uh-sis)
– is the infestation of maggots in or on the body
• Nosocomial myiasis
– is the occurrence of maggot infestation in the hospital setting
• Myiasis can be classified according to type or clinical presentation
• (Robbins & Khachemoune, 2010; Tucker & Goulard, 2008; Merriam-Webster’s collegiate dictionary, 1995).
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6. Myiasis Classification
Classification by type
•Obligate: fly eggs on any host surface
•Facultative: fly eggs on opportunistic areas
•Accidental: fly larvae feed on host not of usual source
Classification by clinical presentation
•Cutaneous
•Orifices
•Intestinal
•Wound
•(Trombetta, Oliva, Galache, Bava, & Troncoso, 2009; Werminghaus, Hoffman, Mehlhorn, & Bas, 2008; Robbins
& Khachemoune, 2010; .Das, Madan, & Gautam, 2010)
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7. Fly Families
• Oestridae family. This is subdivided into 3 subfamilies:
– Oestridae (sounds like es-trid-ee)
– Calliphoridae (sounds like cal-lif-or-id-ee)
– Sarcophagidae (sounds like sar-cof-aj-id-ee)
Specie Examples
• Dermatobia hominis—bot fly–Oestridae family
• Cochliomyia hominivorax—blow fly—Calliphoridae family
• Wohlfahrtia vigil—flesh fly—Sarcophagidae family
• (Robbins & Khachemoune, 2010).
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8. Quiz Question 1
• True of False: The common house fly (Musca domestica) does not cause
myiasis.
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9. Quiz Question 1 Answer
• Answer: False. The common house fly can
cause myiasis. It is facultative
• (“Facultative myiasis-producing flies”, 2011).
December 2011 B. Williams, BSN, RN, MAMS 9
ImageSource:
http://www.naturephoto-cz.eu/musca-domestica-picture-14134.html
Musca domestica
10. Cutaneous Myiasis
• Cutaneous myiasis is subdivided into 3 types by clinical manifestation:
– Furuncular: Larvae presents as a boil lesion
– Migratory: also known as creeping. Larvae moves under skin layers
– Wound: also known as traumatic. Larvae presents in wound bed
• (Robbins & Khachemoune, 2010).
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11. Furuncular Myiasis Epidemiology
• Dermatobia hominis, human bot fly
• Obligate parasite
• Found in Mexico and South America
• Often affects dogs, cats or cattle
• Eggs on surfaces & vectors
• Site specific
• Invasive; it burrows under the skin to cause a boil
• (Trombetta, et al., 2009; Robbins & Khachemoune, 2010; Gingrich,
Spickler, & Davis, 2004).
December 2011 B. Williams, BSN, RN, MAMS 11
Image Source:
http://www.greatapeproject.org/en-US/curiosidade.info/Show/
1942,have-you-ever-eaten-a-buge
Dermatobia hominis
12. Migratory Myiasis Epidemiology
• Gasterophilus spp., horse bot fly
• Most common parasite to horses
• Obligate parasite
• Eggs on the hairs of horses
• Distinct serpentine pattern visible under skin
• Infestation is by contact with an infected horse
• (Robbins & Khachemoune, 2010).
December 2011 B. Williams, BSN, RN, MAMS 12
Image Source:
http://www.slow-life.co.uk/2010/02/03/the-evil-bee/
Gasterophilus spp.
13. Wound Myiasis Epidemiology
• Cochliomyia hominivorax, blow fly
• Obligate parasite
• Distributed in warm areas of the Americas
• Infestation frequently associated with animals
• Female fly lays hundreds of eggs
• Larvae of this specie will feed on living tissue
(usually larvae feed on dead tissue)
• Distinct odor in wound
• Death can result if not treated
• (Trombetta et al., 2009; Robbins & Khachemoune, 2010;
Gingrich, Spickler, & Davis, 2004)
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Image Source:
http://www.icb.usp.br/~marcelcp/Cochliomyia.htm
Cochliomyia hominivorax
14. Quiz Question 2
• True or False: Myiasis is only associated with open areas.
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15. Quiz Question 2 Answer
• False. Myiasis can occur on intact skin.
• (Robbins & Khachemoune, 2010)
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Image Source:
http://www.icb.usp.br/~marcelcp/Dermatobia.htm
Dermatobia hominis
17. Life Cycle
• Fly lay eggs on an area
1. Eggs are deposited on host
2. Eggs hatch usually within 24 hours
3. Larvae emerge from eggs.
• instar (usually up to 3)
• spiracle
1. Mature larvae leave host to pupa.
2. Within pupa, metamorphosis into
reproductive fly
• (Sherman, Roselle, Bills, Danko, & Eldridge, 2005).
December 2011 B. Williams, BSN, RN, MAMS 17
Image Adapted From:
Sherman, R.A., Roselle, G., Bills, C., Danko, L.H., & Eldridge, N. (2005).
Healthcare-associated myiasis: Prevention and intervention.
Infection Control And Hospital Epidemiology, 26(10), 828-832.
Image Adapted From:
Nazni, et al. (2011). Nosocomial nasal myiasis in an intensive care unit.
Malaysian Journal of Pathology, 33(1), 53-56.
Life cycle
Spiracle
19. Signs & Symptoms of Infestation
• Redness, pain, swelling
• Intense itching (pruritus)
• Sensation of movement under skin
• Serous or serosanguinous discharge at site
• Malodor if affected area is wound bed
• *Thread like structure removed
• (Sharma, Pai, & Pai, 2008).
• *Definitive diagnosis of myiasis is by nurse
practitioner or physician if identification of larva
removed from area.
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Image Source:
http://www.langetextbooks.com/_levinson/gallery.php?id=m-n
20. Quiz Question 3
• Describe 2 signs of infestation.
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21. Quiz Question 3 Answer
• Redness (locale)
• Pain (locale)
• Itching (locale)
• Swelling (locale)
• Sensation of movement under skin
• Discharge at site
• Malodor (if in wound bed)
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22. Case Study 1
• A 75-year old woman with venous hypertension and diabetes presented
to the emergency room for an ulcer on the right leg. Necrotic tissue and
tunneling were present in the wound bed. “Worms” were observed by the
nurse assistant. What is the possible clinical presentation?
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23. Case Study 1 Answer
• Answer: Wound myiasis
• (Victoria, Trujillo, & Barreto, 1999).
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24. Case Study
• A 25 year old man from a rural setting presented to an outpatient clinic
complaining of passing worms in the stool for the past month. He had no
complaints of blood in the stool. Blood pressure was within range. Stool
sample collected and lab technician reported 4 active “worms” were
microscopically identified. What is the possible clinical presentation?
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25. Case Study 2 Answer
• Accidental myiasis
• (Das et al., 2010).
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27. Risk Factors
1. Patient
– Limited mobile/immobile; poor hygiene of skin and orifices
– Open wounds not covered
– Immune-compromised
– Cognitively impaired
1. Environment
– Warm climate (e.g. tropical or summer weather season)
– Food containers left uncovered in room
– Overflowing garbage bins in room
• (Sherman et al., 2005).
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28. Nursing Intervention for Myiasis
1. Notify the patient
2. Calm the patient and/or staff
3. Notify the nurse supervisor or nurse manager
4. Locate the medical center policy and protocol to control myiasis
5a. Using standard precautions, remove larvae (NP or MD)
• Brush the larvae out. DO NOT SMOOSH or SMASH. Put intact
larvae aside.
5b. If entire larvae not visible [in skin], apply petroleum jelly
•(Department of Veteran Affairs, Policy Memorandum 512-11, 2009; Sherman et al., 2005; Victoria et al.,
1999).
December 2011 B. Williams, BSN, RN, MAMS 28
29. Nursing Interventions...continued
6. Larvae (all) in specimen cup. Add 70% isopropyl alcohol in cup.
• Seal cup. Label: write patient’s name, date, time, name of
clinician who collected specimen and type of solution.
• Send to lab IMMEDIATELY (within 24 hours).
7. Wipe infected area; use sterile saline or hydrogen peroxide or
Dakin’s solution [0.125% sodium hypochlorite].
8. Soak infected area using hydrogen peroxide and water mixture (1:3)
Soak for approx. 20 minutes.
• (Department of Veteran Affairs, Policy Memorandum 512-11, 2009; Sherman et al., 2005; Victoria et al.,
1999).
December 2011 B. Williams, BSN, RN, MAMS 29
30. Nursing Interventions...continued
9. Dispose of used dressings in proper receptacle. Apply new dressings
10. Document what was done.
• Often, broad-spectrum antibiotic (i.e. Ivermectin) is prescribed
•(Department of Veteran Affairs, Policy Memorandum 512-11, 2009; Sherman et al., 2005; Victoria et al.,
1999).
December 2011 B. Williams, BSN, RN, MAMS 30
31. Critical Reasoning Exercise
• An 83 year old patient with diabetic foot ulcer is diagnosed with
Alzheimer’s and PVD is in your care. You are the charge nurse of the 70
bed nursing home facility and the only RN on shift. The doctor is on call.
The nurse assistant frantically calls for your assistance. The nurse assistant
tells you she was attempting to adjust the sheets in the in the bed and
observed the dressing fell off and “white worms” were seen crawling in
the wound bed. As the charge nurse, apply 2 nursing interventions for
possible myiasis infestation.
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32. Critical Reasoning Exercise Ans.
• Standard precautions and check on the patient to ensure safety.
• Assess vital signs, pain, wound bed. Offer pain med.
• Notify the nurse manager/supervisor. Notify the doctor on call.
• Access myiasis policy/protocol/procedure.
• Perform myiasis removal. Be sure to preserve the larva in 70% Isopropyl
alcohol labeled and sealed in a specimen cup. Clean the wound bed as
stated in protocol.
• Contact lab; notify technician of pending arrival. Send specimen to lab
immediately.
• Document what was done.
• Look for new orders.
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33. Myiasis Prevention
• Cover all wounds
• Change wound dressings as ordered and when visibly soiled
• Keep open orifices clean, especially if patient has an artificial airway
• Establish a turning or repositioning schedule for limited mobile patients
• Thorough skin assessment at least 1 time per week
• Do not leave open food containers in room
• Keep garbage receptacles covered with a lid
• (Sherman et al., 2005)
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35. Conclusion
• Nosocomial myiasis is maggot infestation which occurs in a hospital.
• Common signs/symptoms include redness, pain, itching.
• Risk factors include open wound beds with or without necrotic tissue,
bed-ridden patient and unkempt environment.
• Nosocomial myiasis is preventable.
Additional Information:
The Center for Food Security & Public Health, Iowa State University:
http://cfsph.iastate.edu/DiseaseInfo/disease.php?name=screwworm-myiasis&lang=en
December 2011 B. Williams, BSN, RN, MAMS 35
38. References
• Das, A., Pandey, A., Madan, M., Asthana, A.K., & Gautam, A. (2010). Accidental intestinal myiasis caused
by
genus Sarcophaga. Indian Journal of Medical Microbiology, 28(2), 176-178.
• Department of Veteran Affairs, A Maryland Health Care System: The Infection Control/Hospital
Epidemiology Program (111/MD). (2008). Policy Memorandum (512-11/COS IC-015). Baltimore,
MD: Author.
• Facultative myiasis-producing flies. (2011). The Merck Veterinary Manual. Retrieved from:
http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/71719.htm
• Gingrich, E., Spickler, A.R., & Davis, R. (2004). Screwworm myiasis [PowerPoint presentation]. The Center
for Food Security & Public Health Iowa State University. Retrieved from:
http://cfsph.iastate.edu/DiseaseInfo/disease.php?name=screwworm-myiasis&lang=en
• Myiasis. (1995). In Merriam-Webster’s collegiate dictionary (10th ed.).
• Robbins, K., & Khachemoune, A. (2010). Cutaneous myiasis: A review of the common types of myiasis.
International Journal of Dermatology, 49, 1092-1098.
• Sharma, P., Pai, H.S., & Pai, G.S. (2008). Furuncular myiasis mimicking pyoderma [Letters to Editor]. Indian
Journal of Dermatology, Venerology and Leprology, 74(6), 679-681.
December 2011 B. Williams, BSN, RN, MAMS 38
39. References
• Sherman, R.A., Roselle, G., Bills, C., Danko, L.H., Eldridge, N. (2005). Healthcare-associated myiasis:
prevention and intervention. Infectious Control and Hospital Epidemiology, 26(10), 828-832.
• Trombetta, L., Oliva, A., Galache, V., Bava, J., Troncoso, A. (2009). Cutaneous myiasis due to Cochliomyia
hominovorax in a drug user. Journal of Infection in Developing Countries, 3(11), 873-876.
• Tucker, S. –M., & Goulard, S. (2008). More than just a fly on the wall: A case of nosocomial myiasis in the
intensive care unit. Canadian Association of Critical Care Nurses, 31.
• Victoria, J., Trujillo, R., & Barreto, M. (1999). Myiasis: A successful treatment with topical Ivermectin.
International Journal of Dermatology, 38, 142-144.
• Wa, N., Jeffery, J., Lee, H.L., Lailatul, A.M., Chew, W., Heo, C.C., Sadiyah, I., Khairul, M, -A., Heah, S.K.,
Mohd, H.H. (2011). Nosocomial nasal myiasis in an intensive care unit. Malaysian Journal of
Pathology, 33(1), 53-56.
• Werminghaus, P., Hoffman, T.K., Lehlhorn, H., Bas, M. (2008). Aural myiasis in a patient with Alzheimer’s
disease. European Archives of Otorhinolaryngology, 265(7), 851-853. doi: 10.1007/s00405-007-
0535-2
December 2011 B. Williams, BSN, RN, MAMS 39
40. ENDEND
Bridgette C. Williams, BSN, RN, MAMSBridgette C. Williams, BSN, RN, MAMS
williab5@sunyit.eduwilliab5@sunyit.edu
Notas del editor
-Myiasis
Sounds like (my-eye-uh-sis)
is the infestation of maggots in or on the body; maggots are larvae from flies (Robbins & Khachemoune, 2010).
-Myia
is the Greek word meaning fly (Merriam-Webster’s collegiate dictionary, 1995, p. 769).
-Nosocomial myiasis
is the occurrence of maggot infestation of a person within the hospital setting (Tucker & Goulard, 2008).
-Myiasis can be caused by different types of Dipteria—a two-winged insect (Merriam-Webster’s collegiate dictionary, 1995, p. 327).
-Myiasis can be classified according to type or clinical presentation.
-Myiasis is usually caused by flies from the Oestridae family. This is subdivided into 3 subfamilies:
Oestridae (sounds like es-trid-ee). Greek origin meaning “gadfly or frenzy”
Calliphoridae (sounds like cal-lif-or-id-ee). Greek origin meaning “to bear beauty”
Sarcophagidae (sounds like sar-cof-aj-id-ee) Latin from Greek origin meaning to “to eat flesh”
(Robbins & Khachemoune, 2010).
Specie Examples
-Dermatobia hominis—bot fly– is from the Oestridae family.
-Cochliomya hominivorax—blow fly—is from the Calliphoridae family.
-Wohlfahrtia vigil—flesh fly—is from the Sarcophaidae family.
It is facultative, meaning it usually does not usually cause myiasis. But, if presented with an area (such as an open wound bed). The female fly will lay eggs in the area (“Facultative myiasis-producing flies”, 2011).
Extra-credit question: what does “musca” mean?
Latin word for fly (http://www.memidex.com/musca )
Cutaneous myiasis is subdivided into 3 types by clinical manifestation:
Furuncular:
Larvae presents as a boil lesion.
Migratory:
also known as creeping. Larvae moves under skin layers.
Wound:
also known as traumatic. Larvae presents in wound bed.
-Dermatobia hominis, human bot fly, is an example of a fly specie which cause furuncular myiasis.
-It is a common cause of furuncular myiasis.
-Obligate parasite.
-Commonly from subtropic such as Mexico and South America.
-Often affects dogs, cats or cattle (Trombetta, et al., 2009).
-Female fly lay eggs on surfaces & vectors such as mosquitos (Robbins & Khachemoune, 2010).
-Invasive; it burrows under the skin to cause a boil.
-Eggs hatch on skin & remains in the subdermal layers (deep) of the skin for 5-10 weeks (Robbins & Khachemoune, 2010).
-Usually does not usually affect humans (Gingrich, Spickler, & Davis, 2004).
-Will affect specific sites of the individual (i.e. nose, wound, foot) (Gingrich, Spickler, & Davis, 2004).
Gasterophilus spp., horse bot fly, is an example of a fly specie which causes migratory myiasis.
It is a most common parasite to horses.
Obligate parasite.
Female lay eggs on the hairs of horses.
Larvae hatch on skin and tunnel into the epidermis (superficial) layer of skin. A distinct serpentine pattern is visible under the skin.
Human infestation is by way of contact with an infected horse (Robbins & Khachemoune, 2010).
-Cochliomyia hominivorax, blow fly, is an example of a fly specie which causes wound (traumatic) myiasis.
-Obligate parasite.
-Distributed in warm areas of the Americas (S. America, Mexico and Argentina) (Trombetta et al., 2009).
-Infestation frequently associated with dogs, cats and cattle (Trombetta et al., 2009); rare in humans (Robbins & Khachemoune, 2010). -Eradication program in 1960s via male sterile flies (Gingrich, Spickler, & Davis, 2004)
-Female fly lay hundreds of eggs to cause multiple infestation (Robbins & Khachemoune, 2010).
-Will infect ANY warm-blooded animal (Gingrich, Spickler, & Davis, 2004)
-Eggs hatch in “8-12 hours” after deposit on wound (Gingrich, Spickler, & Davis, 2004)
-Multiple larvae will be present(Gingrich, Spickler, & Davis, 2004)
-Wound will increase in size and depth as the larva feed (Gingrich, Spickler, & Davis, 2004)
-Larva will be visible within 3 days (Gingrich, Spickler, & Davis, 2004)
-Distinct odor (Gingrich, Spickler, & Davis, 2004)
-Death can result if not treated (Gingrich, Spickler, & Davis, 2004)
Dermatobia hominis “favors the skin of scalp, face, and extremities” (Robbins & Khachemoune, 2010, p. 49). After hatching from the egg, the larvae invades the body by the skin of the host (Robbins & Khachemoune, 2010)
With the exception of Sarcophagidae. Flies lay eggs on an area.
Eggs are deposited on host.
Eggs hatch usually within 24 hours.
Larvae emerge from eggs.
Larvae grows in stages called instar, it will change in shape and specific sub-anatomical structures such as spiracle will appear and increase in number with each separate instar stage.
Mature larvae leave host to become pupa.
Within pupa, metamorphosis into reproductive fly (Sherman, Roselle, Bills, Danko, & Eldridge, 2005).
Localized redness, pain, swelling.
Localized intense itching (pruritus).
Sensation of movement under skin.
Serous or serosanguinous discharge at site
Malodor if affected area is wound bed.
*Thread like structure removed (Sharma, Pai, & Pai, 2008).
*Definitive diagnosis of myiasis is by nurse practitioner or physician if identification of larva removed from area.
Accidental myiasis. The patient ate contaminated food and ingested fly eggs. Eggs survived within the intestines and developed into larvae which was excreted out of the body (Das et al., 2010).
Patient
Unable to perform proper self-care.
Bed-ridden; poor hygiene of skin and orifices.
Decreased blood flow to extremities (e.g. Peripheral vascular disease).
Open wounds not covered.
Wounds beds with necrotic tissue in wound bed.
Soiled wound dressings/linens/clothing not promptly changed.
Immune-compromised.
Cognitively impaired.
Environment
Warm climate (e.g. tropical or summer weather season).
Food containers left uncovered in room
Overflowing garbage bins in room (Sherman et al., 2005).
Notify the patient after definitive diagnosis.
Calm the patient; offer comfort, support and empathy. Myiasis is a socially-sensitive diagnosis.
Notify the nurse supervisor or nurse manager.
Locate the medical center policy and protocol to control myiasis
Gather materials to prepare for larval removal:
Basin, 4X4 pads, specimen cups, Isopropyl (70%) alcohol,
Pre-made mixture of 1 part hydrogen peroxide to 3 parts sterile water or sterile saline, marker/pen.
Determine patient’s immune status.
Using standard precautions, express [remove] larvae (NP or MD)
If entire larvae visible, use 4X4 pads to brush the larvae out. DO NOT SMOOSH or SMASH. Put intact larvae aside.
If entire larvae not visible [in skin], apply petroleum jelly to the
affected area on skin. This will occlude the breathing of the larvae thus causing it to move. When visible, use 4X4 pads to brush larvae
out. DO NOT SMOOSH or SMASH. Put intact larvae aside.
6.Using standard precautions, place all larvae into specimen cup. Add
70% isopropyl alcohol into cup; enough to completely submerge
larvae. Seal cup. Label: write patient’s name, date, time, name of
clinician who collected specimen and type of solution (70% isopropyl
alcohol). Send this to lab IMMEDIATELY (within 24 hours).
7.Wipe the infected area using sterile saline or hydrogen peroxide or
Dakin’s solution [0.125% sodium hypochlorite].
8.Soak infected area using hydrogen peroxide and water mixture (step
4a). Soak for 20 minutes.
Dispose of soiled or used dressings in proper receptacle. If possible,
apply new dressings to affected site.
10.Document what was done. Look for new orders (e.g. blood
collection, antibiotic, immunization). Often, a broad-spectrum
antibiotic such as Ivermectin is prescribed (Department of Veteran Affairs,
Policy Memorandum 512-11, 2009; Sherman et al., 2005; Victoria et al., 1999).
Additional Information:
The Center for Food Security & Public Health, Iowa State University
http://cfsph.iastate.edu/DiseaseInfo/disease.php?name=screwworm-myiasis&lang=en