Difference between revisions of "Myiasis"

Latest revision as of 21:29, 26 September 2012

Also Known As: Fly-Strike — Wound Myiasis — Maggots — Strike — Fly Infestation — Wool Maggots

Introduction

Cat with myiasis. Wikimedia Commons

Larval form of Gasterophilus spp stomach botfly. Wikimedia Commons

Myiasis is caused by infestation of live hosts with dipterous larvae. Small and large ruminants and poultry can be affected. These larvae then feed on the host’s living and dead tissue.

Myiasis Producing Flies can be obligate or facultative.

Myiasis Causing Flies

Obligate

Obligate flies occur exclusively in or on living vertebrates.

Oestrus ovis, Gasterophilus spp., Hypoderma spp., Dermatobia spp, Wohlfahrtia spp., Cochliomyia, Chrysomya bezziana and Cordylobia.

Facultative

Facultative flies are free-living and usually found in detritus or carrion.

Cochliomyia macellaria, Chrysomya megacephala, rufifacies and albiceps, Lucilla sericata and cuprina, Phormia spp., Protophormia spp. and Caliphora spp.

For more information, see Myiasis Producing Flies.

Distribution

Myiasis Producing Flies are found in most regions of the world.

Signalment

Presence of wounds, wet fleece in sheep cases, recent surgery, bacterial wool/skin contamination and faecal contamination are the main predisposing factors for myiasis.

Density of stock will determine size and viability of the fly population.

Clinical Signs

Can be classified as cutaneous, nasopharyngeal, intestinal or urogenital. Pain, irritation, discomfort, alopecia and pruritus are common signs locally. There is also likely to be direct tissue damage, haemorrhage, hyperpigmentation and secondary infection.

Nasal myiasis causes irritation and epistaxis.

Aural myiasis can cause deafness, discharge and foul exudates.

Gastrointestinal myiasis caused by Gasterophilus spp. often causes ulceration, GI bleeding, weight loss, diarrhoea and pupae are voided in faeces.

Warble flies cause cysts along the midline of the back.

Lucilia sericata tends to cause lesions on the inner thighs and perineum due to faecal soiling.

Wohlfahrtia' spp. cause genital lesions on the vulva and prepuce.

Loss of feathers and soiling of the vent is seen in poultry.

In severe cases, anaemia, anaphylaxis and toxaemia may be fatal. Likely consequence is reduced feeding and resulting weight loss and infertility.

Diagnosis

Diagnosis is primarily dependent on observation of larvae on the host or in the faeces.

Larvae may also be observed in the carcass at post-mortem.

Gastroscopy may be used in the case of gastric myiasis.

ELISA is also available for Hypoderma spp. and Oestrus ovis. PCR is available for Cochliomyia spp.

Treatment

Treatment with ectoparasiticides is usually effective. Administration can be oral, topical or by subcutaneous injection and the type of myiasis should be considered when deciding upon route of administration.

Ivermectin and doramectin are both effective in the control of nasal myiasis ,warble fly and Dermatobia when injected.

Moxidectin is the main drug for oral treatment. It is effective against Gasterophilus spp.

Topical treatment by pour-on or dipping is most effective against cutaneous/subcutaneous myiasis. A huge range of products are available. Resistance should be considered and monitored.

Control

Preventative treatment with ectoparasiticides is common.

Release of sterile insects is also possible and effective but expensive.

Vaccines are available against Hypoderma spp. and Lucilia spp.

Also see Myiasis in Rabbits

Myiasis Learning Resources
Flashcards Test your knowledge using flashcard type questions	Myiasis Flashcards

Sample Book Chapters
Publisher	Free chapter	Book	Authors

Cutaneous Myiasis

Sheep Medicine

Philip R. Scott

Buy book

References

This article was originally sourced from The Animal Health & Production Compendium (AHPC) published online by CABI during the OVAL Project.

The datasheet was accessed on 6 June 2011.

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@@ Line 1: / Line 1: @@
-Also Known As '''''– Fly-strike – Wound myiasis – Maggots – Strike – Fly infestation – Wool maggots'''''
+{{OpenPagesTop}}
+Also Known As: '''''Fly-Strike — Wound Myiasis — Maggots — Strike — Fly Infestation — Wool Maggots'''''
+Caused By: '''[[Myiasis Producing Flies]]'''
+==Introduction==
 [[File:Myiasis cat.jpg|thumb|200px|right|Cat with myiasis. Wikimedia Commons]]
 [[File:Gasterophilus larvae.jpg|thumb|200px|right|Larval form of ''Gasterophilus spp'' stomach botfly. Wikimedia Commons]]
+Myiasis is caused by infestation of live hosts with '''[[Biting Flies |dipterous larvae]]'''. Small and large ruminants and poultry can be affected. These larvae then feed on the host’s living and dead tissue.
-Caused By – '''[[Myiasis Producing Flies]]'''
+[[Myiasis Producing Flies]] can be '''obligate or facultative'''.
-==Introduction==
-Myiasis is caused by infestation of live hosts with '''[[Biting Flies | dipterous larvae]]'''.
-Small and large ruminants and poultry can be affected.
-These larvae then feed on the host’s living and dead tissue.
-[[Myiasis Producing Flies]] can be '''obligate or facultative'''.
 ==Myiasis Causing Flies==
 ===Obligate===
-'''Obligate flies''' occur exclusively '''in or on''' living vertebrates.
+'''Obligate flies''' occur exclusively '''in '''or''' on''' living vertebrates.
-''[[Oestrus ovis]], [[Gasterophilus spp.]], [[Hypoderma spp.]], [[Dermatobia hominis | Dermatobia spp]], [[Wohlfahrtia spp.]], Cochliomyia, [[Chrysomya bezziana]] and Cordylobia.''
+''[[Oestrus ovis]]'', [[Gasterophilus spp.|''Gasterophilus'' spp.]], [[Hypoderma spp.|''Hypoderma'' spp.]], [[Dermatobia hominis |''Dermatobia ''spp]], [[Wohlfahrtia spp.|''Wohlfahrtia'' spp.]], ''Cochliomyia, [[Chrysomya bezziana]]'' and ''Cordylobia.''
 ===Facultative===
 '''Facultative''' flies are '''free-living''' and usually found in detritus or carrion.
-''Cochliomyia macellaria, Chrysomya megacephala, rufifacies'' and ''albiceps, Lucilla sericata and cuprina, Phormia spp, Protophormia spp'' and ''Caliphora spp.''
+''Cochliomyia macellaria, Chrysomya megacephala, rufifacies'' and ''albiceps, Lucilla sericata'' and cuprina, Phormia ''spp., ''Protophormia ''spp. and ''Caliphora'' spp.
-For more information, see [[Myiasis Producing Flies]]
+For more information, see [[Myiasis Producing Flies]].
 ==Distribution==
 [[Myiasis Producing Flies]] are found in most regions of the world.
 ==Signalment==
 Presence of '''wounds, wet fleece''' in sheep cases, recent '''surgery''', bacterial wool/skin contamination and '''faecal contamination''' are the main predisposing factors for myiasis.
 Density of stock will determine size and viability of the fly population.
 ==Clinical Signs==
-Can be classified as '''cutaneous, nasopharyngeal, intestinal''' or '''urogenital'''.
+Can be classified as '''cutaneous, nasopharyngeal, intestinal''' or '''urogenital'''. '''Pain, irritation, discomfort, alopecia''' and '''pruritus''' are common signs locally. There is also likely to be '''direct tissue damage, haemorrhage''', hyperpigmentation and secondary infection.
-'''Pain, Irritation, Discomfort, Alopecia''' and '''Pruritus''' locally.
+[[Oestrus ovis |'''Nasal myiasis''']] causes irritation and [[Epistaxis |epistaxis]].
-'''Direct tissue damage, haemorrhage''', hyperpigmentation and secondary infection.
-[[Oestrus ovis | '''Nasal myiasis''']] causes irritation and [[Epistaxis | epistaxis]].
 '''Aural myiasis''' can cause deafness, discharge and foul exudates.
-[[Gasterophilus spp. | '''Gastrointestinal myiasis''']] often causes '''ulceration, GI bleeding''', weight loss, [[Diarrohea | diarrhoea]] and pupae are voided in faeces.
+'''Gastrointestinal myiasis''' caused by [[Gasterophilus spp.|''Gasterophilus'' spp.]] often causes '''ulceration, GI bleeding''', weight loss, [[Diarrhoea |diarrhoea]] and pupae are voided in faeces.
-[[Hypoderma spp. | '''Warble flies''']] cause '''cysts''' along the midline of the '''back'''.
+[[Hypoderma spp. |'''Warble flies''']] cause '''cysts''' along the midline of the '''back'''.
-''Lucilia sericata'' tends to cause leions on the inner '''thighs and perineum''' due to faecal soiling.
+''Lucilia sericata'' tends to cause lesions on the inner '''thighs and perineum''' due to faecal soiling.
-''[[Wohlfahrtia spp.]]'' cause '''genital lesions''' on the vulva and prepuce.
+''[[Wohlfahrtia spp.|''Wohlfahrtia' spp.]]'' cause '''genital lesions''' on the vulva and prepuce.
 '''Loss of feathers''' and soiling of the vent is seen in '''poultry'''.
-In severe cases, anaemia, anaphylaxis and toxaemia may be fatal.
+In severe cases, anaemia, anaphylaxis and toxaemia may be fatal. Likely consequence is reduced feeding and resulting weight loss and infertility.
-Reduced feeding and consequent weight loss and infertility.
 ==Diagnosis==
@@ Line 64: / Line 56: @@
 Larvae may also be observed in the carcass at '''post-mortem'''.
-Gastroscopy may be used in the case of [[Gasterophilus spp. | gastric myiasis]].
+Gastroscopy may be used in the case of [[Gasterophilus spp. |gastric myiasis]].
-'''[[ELISA testing | ELISA]]''' is also available for ''[[Hypoderma spp.]]'' and ''[[Oestrus ovis]]''.
-'''PCR''' is available for ''Cochliomyia spp''.
+'''[[ELISA testing | ELISA]]''' is also available for [[Hypoderma spp.|''Hypoderma'' spp.]] and ''[[Oestrus ovis]]''. '''PCR''' is available for ''Cochliomyia spp''.
 ==Treatment==
-Treatment with '''[[Ectoparasiticides | ectoparasiticides]]''' is usually effective.
+Treatment with '''[[Ectoparasiticides |ectoparasiticides]]''' is usually effective. Administration can be '''oral, topical or by subcutaneous injection''' and the type of myiasis should be considered when deciding upon route of administration.
-Administration can be '''oral, topical or by subcutaneous injection''' and the type of myiasis should be considered when deciding upon route of administration.
-'''Ivermectin''' and '''doramectin''' are both effective in the control of [[Oestrus ovis | nasal myiasis]] ,[[Hypoderma spp. | warble fly]] and [[Dermatobia hominis | Dermatobia]] when '''injected'''.
+'''Ivermectin''' and '''doramectin''' are both effective in the control of [[Oestrus ovis |nasal myiasis]] ,[[Hypoderma spp. |warble fly]] and [[Dermatobia hominis |''Dermatobia'']] when '''injected'''.
-'''Moxidectin''' is the main drug for '''oral treatment'''. It is effective against [[Gasterophilus spp.]].
+'''Moxidectin''' is the main drug for '''oral treatment'''. It is effective against [[Gasterophilus spp.|''Gasterophilus'' spp.]]
 '''Topical treatment''' by '''pour-on or dipping''' is most effective against '''cutaneous/subcutaneous myiasis'''. A huge range of products are available. Resistance should be considered and monitored.
 ==Control==
-Preventative treatment with '''[[Ectoparasiticides | ectoparasiticides]]''' is common.
+Preventative treatment with '''[[Ectoparasiticides |ectoparasiticides]]''' is common.
 Release of '''sterile insects''' is also possible and effective but expensive.
-'''Vaccines''' are available against ''[[Hypoderma spp]]'' and ''Lucilia spp.''
+'''[[Vaccines]]''' are available against [[Hypoderma spp.|''Hypoderma ''spp.]] and ''Lucilia spp.''
+<b><big>Also see [[Cutaneous Blowfly Myiasis – Rabbit|Myiasis in Rabbits]]</big></b>
+{{Learning
+|flashcards = [[Myiasis Flashcards]]
+}}
+{{Chapter}}
+{{Mansonchapter
+|chapterlink = http://www.mansonpublishing.co.uk/book-images/9781840760491_sample.pdf
+|chaptername = Cutaneous Myiasis
+|book = Sheep Medicine
+|author = Philip R. Scott
+|isbn = 9781840761498
+}}
 ==References==
 <references/>
-Animal Health & ProductIon Compendium, '''Myiasis datasheet''', accessed 06/06/2011 @ http://www.cabi.org/ahpc/
+{{CABI source
+|datasheet = [http://www.cabi.org/ahpc/?compid=3&dsid=74573&loadmodule=datasheet&page=2144&site=160 myiasis-causing flies]
+|date =6 June 2011
+}}
+<br><br><br>
+{{review}}
+{{OpenPages}}
 [[Category:Integumentary System - Parasitic Infections]]
-[[Category:To_Do_-_CABI review]]
+[[Category:CABI Expert Review]][[Category:CABI AHPC Pages]]