pythiosis general
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Pythium insidiosum: Diagnosis and Treatment
Pythium insidiosum: Diagnosis and Treatment
Robert L. GlassPan American Veterinary Laboratories
Robert L. GlassPan American Veterinary Laboratories
Pythium insidiosumPythium insidiosum
Kingdom Stramenipila Kingdom Stramenipila
Oomycete “aquatic fungus” Oomycete “aquatic fungus”
Hyphal elements similar to Fungi Hyphal elements similar to Fungi
Primarily an infectious agent of plants Primarily an infectious agent of plants
PythiosisPythiosis
PhycomycosisPhycomycosis
Florida Horse LeechesFlorida Horse Leeches
Swamp CancerSwamp Cancer
Species Infected bySpecies Infected by Pythium insidiosum Pythium insidiosumCanineCanine Australia, Brazil, Korea, USA and VenezuelaAustralia, Brazil, Korea, USA and Venezuela
EquineEquine Australia, Brazil, Colombia, Costa Rica, New Zealand, Australia, Brazil, Colombia, Costa Rica, New Zealand, New Guinea, USA and VenezuelaNew Guinea, USA and Venezuela
FelineFeline USAUSA
Bovine Bovine Brazil, USA and VenezuelaBrazil, USA and Venezuela
HumanHuman Australia, New Zealand, Haiti, India ThailandAustralia, New Zealand, Haiti, India Thailand and the USAand the USA
Bear Bear USAUSA
Camel Camel USAUSA
Incidence of Pythiosis in the USIncidence of Pythiosis in the US
1995-2003 158 cases (all species)2004 72 cases (all species)2005 (Jan-Aug) 102 cases (all species)2010 752 cases (all species)
EpidemiologyEpidemiology
OosporeOospore
Life CycleLife Cycle
Skin
SkinSkininjuryinjury
Skin
PythiosisPythiosisPythiosisPythiosis
ClinicalClinical Characteristics of pythiosisCharacteristics of pythiosis
- Cutaneous Cutaneous Keratinitis Keratinitis
NecrosisNecrosis- SubcutaneousSubcutaneous LymphaticLymphatic
PeriorbitalPeriorbital
- Arterial Arterial Large arteriesLarge arteries AneurysmAneurysm
- Intestinal Intestinal Intestinal tractIntestinal tract
- SystemicSystemic LiverLiver
LungsLungs
FelineFeline PythiosisPythiosis
CanineCanine PythiosisPythiosis
Intestinal pythiosis in canines is often misdiagnosed as lymphoma.
Bovine PythiosisBovine Pythiosis Venezuela Venezuela
EquineEquine PythiosisPythiosis
““kunkers”kunkers”
Chronic PythiosisChronic Pythiosis Osteo infectionOsteo infection
Human pythiosis in the USAHuman pythiosis in the USA
Tennessee 1998Tennessee 1998 Texas 1989Texas 1989
Human Pythiosis, ThailandHuman Pythiosis, Thailand
IgGIgGIgMIgM
PythiosisExperimental
PythiosisExperimental
Laboratory DiagnosisLaboratory Diagnosis
1) Very few laboratories are familiar with P. Insidiosum
2) Difficult to culture
3) Difficult to identify in histopath studies
4) Difficult to identify by clinical presentation
1) Very few laboratories are familiar with P. Insidiosum
2) Difficult to culture
3) Difficult to identify in histopath studies
4) Difficult to identify by clinical presentation
Conidiobolus coronatusConidiobolus coronatus Basidiobolus ranarum Basidiobolus ranarum Fungal zygomycetesFungal zygomycetes
Pythium insidiosumPythium insidiosum OomyceteOomycete
Differential DiagnosisDifferential Diagnosis
Wet mountWet mount10% KOH10% KOHWet mountWet mount10% KOH10% KOH Immune-fluorescenceImmune-fluorescenceImmune-fluorescenceImmune-fluorescence
CultureCultureCultureCultureHistopathologyHistopathologyHistopathologyHistopathology
immunoperoxidaseimmunoperoxidaseimmunoperoxidaseimmunoperoxidase
Tissue Biopsy Studies
Serologic DiagnosisSerologic DiagnosisAgar Gel Immunodiffusion
Western Blot
Classical treatments usedagainst Pythium insidiosumClassical treatments usedagainst Pythium insidiosum
Surgery ~40%
Iodines ~35-40%
Amphotericine B <30%Itraconazole <30%
Surgery ~40%
Iodines ~35-40%
Amphotericine B <30%Itraconazole <30%
What is Pythium Immunotherapy?What is Pythium Immunotherapy?
Allergy desensitization via Subcutaneous presentation of purified P. insidiosum antigens Allergy desensitization via Subcutaneous presentation of purified P. insidiosum antigens
Switching of the of the immune response from TH2 (allergic) to TH1 mode (protective and curative)
ImmunotherapyImmunotherapy
T helper 2 responseT helper 2 response
EosinophilsEosinophils Mast cellsMast cells IgEIgE IL5IL5 IL4IL4
T helper 1 responseT helper 1 response
MacrophagesMacrophages T lymphocytesT lymphocytes (cytotoxic?)(cytotoxic?) IFNIFN IL2IL2
ImmunotherapyImmunotherapy
Pythium Infection
Infection Cleared
Before ImmunotherapyBefore Immunotherapy Day 4 Day 4 Day 8 Day 8 Day 15 Day 15
Pythium antibody in Canines participating in Field Pythium antibody in Canines participating in Field Trial Training and CompetitionsTrial Training and Competitions
Result #Dogs % of TotalResult #Dogs % of Total
Negative 105 61.4 Negative 105 61.4
Borderline 43 25.1Borderline 43 25.1
Positive Positive 23 13.5 23 13.5
Total 171 100 Total 171 100
* Normal Dogs <1 % Positive ,<5% Borderline, >95% Negative* Normal Dogs <1 % Positive ,<5% Borderline, >95% Negative
Pythium Associated Symptoms in Field Trial/Hunt Pythium Associated Symptoms in Field Trial/Hunt CaninesCanines
VOMITING/DIARRHEAVOMITING/DIARRHEA IN LAST 12 MONTHSIN LAST 12 MONTHS
Blood testBlood test
Negative 7 (6.7%)Negative 7 (6.7%)
Borderline 3 (7.0%)Borderline 3 (7.0%)
Positive 13 (26.1%) Positive 13 (26.1%)
Efficacy of Pythium Immunotherapy
Studies Conducted 2004-2005Studies Conducted 2004-2005
Species # Treated # Successes # Failures %Success
Equine 58 52 6 90%
Canine 28 15 13 53%
Bovines 65 65 0 100%
Efficacy of Pythium V2 ImmunotherapyIn Canines
Studies Conducted 2007-2008Studies Conducted 2007-2008
# Treated # Successes # Failures %Success
14 10 4 71%
ImmunotherapyImmunotherapy
BeforeBefore
AfterAfter
BeforeBefore
AfterAfter
TreatmentRegimen
1cc Sub Q
Day 1 Day 7 Day 21
8/22/03 9/27/03
11/25/033/17/04
Immunotherapy
Treatment
Progression
Surgery + ImmunotherapySurgery + Immunotherapy
Immunotherapy
Purified protein extract of P. insidiosum
Early treatment increases success rate
Use as first option treatment
>85% effective in equines, 50% effective in canines
Combine with surgical de bulking in chronic cases
Pythium insidiosum is endemic in tropical and subtropical regions
Differential diagnosis includes subcutaneous mycosis, lymphoma, parasitic and bacterial infections Serologic diagnosis is fast and accurate
Itraconazole, Amphotericin B, Iodine and surgery have shown limited success
Immunotherapy alone or in conjunction with other therapies demonstrates highest success rate
Pythium insidiosum is endemic in tropical and subtropical regions
Differential diagnosis includes subcutaneous mycosis, lymphoma, parasitic and bacterial infections Serologic diagnosis is fast and accurate
Itraconazole, Amphotericin B, Iodine and surgery have shown limited success
Immunotherapy alone or in conjunction with other therapies demonstrates highest success rate
Lagenidium gigantumLagenidium gigantum
Similar to Pythium in classSimilar to Pythium in class
Similar to Pythium in disease Similar to Pythium in disease characteristicscharacteristics
Essentially identical to Pythium in Essentially identical to Pythium in tissue sectionstissue sections
Does not respond to Pythium Does not respond to Pythium ImmunotherapyImmunotherapy
Accurate Diagnosis is Essential Accurate Diagnosis is Essential
Clinical presentation is not good Clinical presentation is not good enoughenough
Histopath examination is not good Histopath examination is not good enoughenough
Pythium test alone is not good enoughPythium test alone is not good enough
Accurate diagnosis requires blood test Accurate diagnosis requires blood test for both Pythium and Lagenidiumfor both Pythium and Lagenidium