Diseases / List of Parasitic Diseases / Disease description:
Sphaeridiotrema globulus (Intestinal Fluke) Infection in Waterfowl

INFORMATION AVAILABLE

GENERAL INFORMATION

CLINICAL CHARACTERISTICS & PATHOLOGY

INVESTIGATION & DIAGNOSIS

TREATMENT & CONTROL

SUSCEPTIBILITY & TRANSMISSION

ENVIRONMENT & GEOGRAPHY

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General and References

Disease Summary
WATERFOWL Acute onset anaemia, weakness and deaths due to ulcerative haemorrhagic enteritis caused by flukes (trematodes) feeding attached to small-intestinal mucosa.

N. B. See also: Cyathocotyle bushiensis (Intestinal Fluke) Infection; Intestinal Fluke Infestation.

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Alternative Names (Synonyms)

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Disease Type
 Viral

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Infectious/Non-Infectious Agent associated with the Disease
A small trematode (fluke), Sphaeridiotrema globulus (Synonyms: Distoma globulus, Cercaria helvetica).

Infective "Taxa"

Non-infective agents

 --

Physical agents

 -- Indirect / Secondary

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References

Disease Author

 Debra Bourne
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Major References / Reviews

Code and Title List

 B15, B36.35.w35
J1.19.w3, J1.24.w3, J1.25.w2
J5.26.w3

Other References

Code and Title List

 B16.19.w1, B91

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Clinical Characteristics and Pathology

Detailed Clinical and Pathological Characteristics

General

 WATERFOWL Acute-onset weakness, severe anaemia, haemorrhagic ulcerative enteritis, death.

N. B. See also: Cyathocotyle bushiensis (Intestinal Fluke) Infection; Intestinal Fluke Infestation.

Clinical Characteristics

 WATERFOWL Weakness: inability to fly or to hold stationary on water against the wind, wing droop, limberneck or slow bobbing of head forwards and backwards, unsteady gait, disorientation; watery blood-stained diarrhoea. Terminally may show convulsions with wing flapping and extension of feet backwards, and may pass blood from the cloaca. Vent feathers may be stained with blood. Death may occur due to hypovolaemic shock.

(J1.19.w3, J1.25.w2, J5.26.w3, B36.35.w35).

Incubation

 WATERFOWL Acute infection. Five days with experimental infection (J1.25.w2). Deaths usually 3-8 days after ingestion of a lethal number of the parasites (B36.35.w35).

Mortality / Morbidity

 WATERFOWL Mortality can be high, reaching 100% (J5.26.w3).

Pathology

 WATERFOWL Clinical Pathology:
  • Severe anaemia - packed cell volume (PCV, haematocrit) 1% to 7% noted in moribund swans, with hemoglobin concentrations below 4g/dl and erythrocyte counts 0.20-0.45 x 106 /mm3 .
  • Blood parameters may be decreased by as soon as three days after infection with large numbers of metacercariae, with slower drop noted with lower infection rates. Immature erythrocytes (round, basophilic) present (J1.25.w2, J5.26.w3, B36.35.w35).

Gross Pathology:

  • General - pronounced pallor of skeletal muscles, myocardium, lungs. Good general body condition.
  • Heart - petechiae and sometimes white streaking on ventricular myocardium. Serous hydropericardium.
  • Liver - Friable, walnut-brown, bile-streaked. Distended gall bladder.
  • Spleen - sometimes enlarged
  • Gastro-intestinal tract - Haemorrhagic to fibrino-haemorrhagic ulcerative enteritis. Distended lower small intestine (jejunum and ileum), with general cyanotic appearance in severe cases. Haemorrhagic foci (surrounding trematodes) sometimes visible through serosa. Grossly congested intestinal veins and arterioles. Large quantities of liquid blood in jejunum and ileum, together with fibrinous casts or cores containing parasites and desquamated epithelium. Parasites (1mm long) in small groups (three to about twenty) in area of intestine attached to mesentery (where blood vessels enter).

Histopathology:

  • Gastro-intestinal tract - Trematodes attached to mucosa of jejunum and ileum by large acetabulae. Ulceration of mucosa through muscularis mucosae into circular muscle layer. Intestinal villi severely eroded, appearing as mounds of loose connective tissue, with crypts obliterated, damage to capillaries and associated haemorrhage. Cellular infiltration of villi, mainly with lymphocytes, also a few neutrophils and eosinophils.
  • Liver - periportal hepatitis with lymphocytic infiltration. Nests of erythroblasts in sinusoids (extramedullary haematopoiesis).
  • Femoral bone marrow - erythroid hyperplasia.
  • Spleen - reactive, with secondary nodules.

(J1.19.w3, J1.25.w2, J5.26.w3, B36.35.w35)

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Human Health Considerations
No reports of infection in humans (B36.35.w35).

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Susceptibility / Transmission

General information on Susceptibility / Transmission
WATERFOWL Susceptibility
  • varies with waterfowl species; mute swans Cygnus olor appear to be more susceptible than Canada geese Branta canadensis or mallard Anas platyrhynchos.

Transmission

  • is by ingestion of snails (second intermediate host) containing Sphaeridiotrema globulus metacercaria.
  • Feeding habits may affect exposure to the parasite by affecting the likelihood of ingesting infected snails.
  • Resistance may develop following a small initial infection.
  • Outbreaks often involve only on mainly one species of waterfowl, which may be related to feeding habits.
  • Young birds may be more susceptible.
  • Concurrent infection of Sphaeridiotrema globulus with Cyathocotyle bushiensis may be more pathogenic than infection of either trematode alone (J1.24.w3).

(J1.25.w2, J5.26.w3, B15, B36.35.w35)

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Disease / Agent has been reported in either the wild or in captivity in:
  • Mute swan Cygnus olor in New Jersey, USA (J5.26.w3)
  • Whistling swan Cygnus columbianus in New Jersey, USA (J1.19.w3)
  • Mute swan Cygnus olor, Canada goose Branta canadensis, mallard Anas platyrhynchos (experimental infection) (J1.25.w2).
  • Lesser scaup Aythya affinis, canvasbacks Aythya valisineria, long-tailed ducks (oldsquaw) Clangula hyemalis, Muscovy ducks Cairina moschata, green-winged teal Anas crecca, mallard Anas platyrhynchos, American black ducks Anas rubripes, bufflehead Bucephala albeola, common goldeneye Bucephala clangula, and by experimental infection domestic ducklings (B15).
  • May be associated with recurrent late-summer mortality in dabbling ducks in southern Quebec, Canada. Infection recorded in American black ducks Anas rubripes, mallard Anas platyrhynchos, mallard x American black ducks, blue-winged teal Anas discors, green-winged teal Anas crecca, wood duck Aix sponsa, pintail Anas acuta, gadwall Anas strepera, ring-necked duck Aythya collaris (J1.24.w3).
  • Anser albifrons - Greater white-fronted goose (Experimental), Cygnus cygnus - Whooper swan, Anas platyrhynchos domesticus - Domestic duck, Anas acuta - Northern pintail, Anas crecca - Common teal, Anas penelope - Eurasian wigeon, Anas querquedula - Garganey, Aythya affinis - Lesser scaup, Aythya ferina - Common pochard, Aythya fuligula - Tufted duck, Aythya marila - Greater scaup, Aythya valisineria - Canvasback, Bucephala clangula - Common goldeneye, Clangula hyemalis - Long-tailed duck, Mergus merganser - Common merganser, Mergus serrator - Red-breasted merganser, Oxyura leucocephala - White-headed duck. (B91)

WATERFOWL Host Species List

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Disease / Agent has been specifically reported in Free-ranging populations of:
  • Mute swan Cygnus olor in New Jersey, USA (J5.26.w3)
  • Whistling swan Cygnus columbianus in New Jersey, USA (J1.19.w3)
  • Lesser scaup Aythya affinis, canvasbacks Aythya valisineria, long-tailed ducks (oldsquaw) Clangula hyemalis, green-winged teal Anas crecca, mallard Anas platyrhynchos, American black ducks Anas rubripes, bufflehead Bucephala albeola, common goldeneye Bucephala clangula (B15).
  • May be associated with recurrent late-summer mortality in dabbling ducks in southern Quebec, Canada. Infection recorded in American black ducks Anas rubripes, mallard Anas platyrhynchos, mallard x American black ducks, blue-winged teal Anas discors, green-winged teal Anas crecca, wood duck Aix sponsa, pintail Anas acuta, gadwall Anas strepera, ring-necked duck Aythya collaris in southern Quebec, Canada (J1.24.w3).

WATERFOWL Host Species List

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Environment/Geography
General Information on Environmental Factors/Events and Seasonality
  • Dependent on the presence of the intermediate host snails. Notable seasonal incidence of reported epornitics which may be associated with level of infection in intermediate hosts (snails) and seasonal movements (thus availability) of intermediate hosts. Often also associated with a change in the weather; stress of adverse weather conditions may be a factor in mortality. (J5.26.w3, B15).
  • Highest level of acquisition of infection in sentinel blue-winged teal Anas discors in late summer (July-September) in Quebec, Canada (J1.24.w3).

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Regions / Countries where the Infectious Agent or Disease has been recorded

USA, Canada, Australia, 'Old World' (J1.19.w3, J1.24.w3, J1.25.w2, J5.26.w3, B15, B36.35.w35).

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Regions / Countries where the Infectious Agent or Disease has been recorded in Free-ranging populations

USA, Canada (J1.19.w3, J1.24.w3, J1.25.w2, J5.26.w3, B15).

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General Investigation / Diagnosis

General Information on Investigation / Diagnosis
WATERFOWL Clinical signs, pathological lesions, in association with Sphaeridiotrema globulus trematodes. (J1.25.w2).
Related Techniques
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Similar Diseases (Differential Diagnosis)
WATERFOWL Duck plague (lethargy, blood-stained vent) (Duck Plague) (B36.35.w35).

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Treatment and Control

Specific Medical Treatment
WATERFOWL Treatment of trematode infections is difficult. Tetramisole, oral, 25-50mg/kg body weight may be partially effective (B16.19.w1).
Related Techniques
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General Nursing and Surgical Techniques
WATERFOWL --
Related Techniques

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Preventative Measures
Vaccination WATERFOWL --
Prophylactic Treatment

WATERFOWL

 --
Related Techniques

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Environmental and Population  Control Measures
General Environment Changes, Cleaning and Disinfection

WATERFOWL

 --
Population Control Measures WATERFOWL --
Isolation, Quarantine and Screening WATERFOWL --
Related Techniques
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