T

FREE CERCARtA FLOATE rt_E ACH - LI KE"\ \ nOTiON /

EGG IN SpyryM OR.

SWALLOWED EEG PASSED

IN FECF5

DEPOSITED IN OR NEAR WATËR

MASS

DEVELOPS INTO MlflAC) DI UM

in 15 -20 DAYS

ENTERS FIRST INTERMEDIATE HOS SNAIL

GRAM!F ERA \ TUBERCULATA J

ASEXUAL GENERATIONS SPOROCYST—MOTHER REDIA DAUGHTER REDIA--CERCAR Î A

Figure 3-16. Life cycle of Paragonimus westermani.

Paragonimus westermani (continued) OVA

SIZE: 95 x 55 mcm (medium to large; four end-to-end span in HPF). SHAPE: Oval COLOR: Golden brown OPERCULUM: Present at broad end.

CONTENT: Yolk mass "differentiated," variable size of granules in the yolk. ABOPERCULAR THICKENING

SIZE: 10 to 14 mm long by 3 to 5 mm wide (large). SHAPE: Oval body. COLOR: Reddish brown. INTESTINAL CECA: Undulating.

ORGANISM 5--Opisthorchis sinensis (Clonorchis sinensis)

GENERAL CHARACTERISTICS

COMMON NAME: Chinese liver fluke. GEOGRAPHICAL DISTRIBUTION: Asia

PATHOGENISIS: Mechanical and toxic irritations to liver, destruction of liver parenchyma, jaundice, adenomatous proliferation of tissue cells and liver cirrhosis. HABITAT: Bile passages. INTERMEDIATE HOST FIRST: Snail. SECOND: Fish. RESERVOIR HOST: Piscivores. INFECTIVE FORM: Metacercaria. MODE OF INFECTION: Ingestion. SPECIMEN OF CHOICE: Feces.

Figure 3-18. Life cycle of Opisthorchis sinensis.

SIZE: 30 x 15 mcm (small, 12 end to end per HPF). SHAPE: Vaselike. COLOR: Yellowish-brown. OPERCULUM: Present, pronounced.

CONTENT: Asymmetrical miracidium, "boxer's glove" appearance. ABOPERCULAR COMMA: May be seen. BROAD OPERCULAR SHOULDERS

COMMA PROCESS Figure 3-19. Stages of Opisthorchis sinensis. (continued)

ADULT

SIZE: 10 to 20 mm long by 2 to 5 mm wide (medium). SHAPE: Oval, elongated. COLOR: Golden brown to pinkish. INTESTINAL CECA: Straight. TESTES: Dendritic and tandem.

Figure 3-19. Stages of Opisthorchis sinensis. (concluded)

ORGANISM 6--Opisthorchis species--O. viverrini and O. felineus

GENERAL CHARACTERISTICS

COMMON NAME: Cat liver fluke.

GEOGRAPHICAL DISTRIBUTION: O. viverrini, Thailand and Laos--O. felineus,

Europe, Russia, and Vietnam. PATHOGENESIS: Mechanical obstruction and toxic irritations in biliary passages, jaundice. HABITAT: Bile passages. INTERMEDIATE HOST FIRST: Snail. SECOND: Fish.

Opisthorchis species--O. viverrini and O. felineus (continued)

RESERVOIR HOST: Piscivores. INFECTIVE FORM: Metacercaria. MODE OF INFECTION: Ingestion. SPECIMEN OF CHOICE: Feces.

Figure 3-20. Life cycle of Opisthorchis species.

Opisthorchis species--O. viverrini and O. felineus (continued)

SIZE: 30 x 15 mcm (small) (12 end to end per HPF). SHAPE: Vaselike. COLOR: Yellowish-brown. OPERCULUM: Present, pronounced. CONTENT: Miracidium.

SHAPE: Oval, elongated

COLOR: Grey to brown

INTESTINAL CECA: Straight

TESTES: Lobed and oblique

viverrini

Figure 3-21. Stages of Opisthorchis species.

viverrini

OPISTHORCHIS FELINEUS

Figure 3-21. Stages of Opisthorchis species.

ORGANISM 7--Dicrocoelium dendriticum

GENERAL CHARACTERISTICS

COMMON NAME: Lancet fluke. GEOGRAPHICAL DISTRIBUTION: Cosmopolitan.

PATHOGENESIS: Inflammation of biliary epithelium, biliary dysfunction, edema, toxemia.

HABITAT: Liver INTERMEDIATE HOST FIRST: Land snail. SECOND: Black ant (Formica fusca). RESERVOIR HOST: Herbivores. INFECTIVE FORM: Metacercaria. MODE OF INFECTION: Ingestion. SPECIMEN OF CHOICE: Feces.

Figure 3-22. Life cycle of Dicrocoelium dendriticum.

SIZE: 40 x 25 mcm. SHAPE: Oval (race track). COLOR: Light brown. OPERCULUM: Present, indistinct. CONTENT: Miracidium.

ADULT

SIZE: 5 to 12 mm long by 1.5 to 2.5 mm wide (medium). SHAPE: Elongated, lancet. COLOR: Transparent. INTESTINAL CECA: Straight.

TESTES: Shallow lobed and oblique; found in anterior half of the body.

Figure 3-23. Stages of Dicrocoelium dendriticum.

ORGANISM 8--Fasciola hepatica GENERAL CHARACTERISTICS

COMMON NAME: Sheep liver fluke.

GEOGRAPHICAL DISTRIBUTION: Worldwide; sheep-raising countries. PATHOGENESIS: Mechanical and toxic irritation to liver, destruction of hepatic parenchyma, biliary obstruction, adenomatous and fibrotic changes, anemia (0.2 ccblood loss per worm per day), eosinophilia, cirrhosis (periportal). HABITAT: Bile passages. INTERMEDIATE HOST FIRST: Snail.

SECOND: Fresh water vegetation (watercress). RESERVOIR HOST: Herbivores and carnivores. INFECTIVE FORM: Metacercaria. MODE OF INFECTION: Ingestion SPECIMEN OF CHOICE: Feces.

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