Trematodes (Flukes) Department of Parasitology, Xiangya Medical School, Central South University
Trematodes (Flukes) Department of Parasitology, Xiangya Medical School, Central South University
Paragonimus westermani (lung fluke)
Paragonimus westermani (lung fluke)
Discovery More than 50 species of paragonimus have been reported as parasites. P.Westermani is widely distributed in East Asia and is the most important species. It was first discovered from Bengal tigers that had died in the zoos in Europe in 1878. In 1880,human infections were first found in Taiwan of China
⚫ More than 50 species of paragonimus have been reported as parasites. ⚫ P. Westermani is widely distributed in East Asia and is the most important species. ⚫ It was first discovered from Bengal tigers that had died in the zoos in Europe in 1878. ⚫ In 1880, human infections were first found in Taiwan of China Discovery
Morphology 1、Adult worm Thick,reddish-brown in color,a flattened ventral side,a swelled dorsal side,like half a peanut,(7.5-12.0mmx4-6mm) Oral sucker ventral sucker are similar in size;ventral sucker is at pre- equator Two testes,the ovary and the uterus are situated side by side Cecum with two winding branches Vitelline follicles are extensive in lateral fields
Morphology 1、Adult worm ⚫ Thick, reddish-brown in color,a flattened ventral side,a swelled dorsal side, like half a peanut,(7.5-12.0mmx4-6mm) ⚫ Oral sucker & ventral sucker are similar in size;ventral sucker is at preequator ⚫ Two testes, the ovary and the uterus are situated side by side ⚫ Cecum with two winding branches ⚫ Vitelline follicles are extensive in lateral fields
Morphology 1、Adult worm Surface with spines
Morphology 1、Adult worm Surface with spines
Morphology 2、Eg9 ●Average size:85μmX53μm ●Golden yellow, ●Irregular elliptic, Thick and asymmetric shell with a big operculum, Inside,a egg cell surrounded by about ten yolk cells 9828KU56U
Morphology 2、Egg ⚫ Average size: 85μm X 53μm ⚫ Golden yellow, ⚫ Irregular elliptic, ⚫ Thick and asymmetric shell with a big operculum, ⚫ Inside, a egg cell surrounded by about ten yolk cells
Morphology 3、Metacercaria ●Spherical, ●About300-400 um with two layers of transparent walls in crab and crayfish
Morphology 3、 Metacercaria ⚫ Spherical, ⚫ About 300-400µm with two layers of transparent walls in crab and crayfish
Life Cycle e way in hur hwate Te行st inte
Life Cycle
Life Cycle Adults --- 哥 Miracidum Sporocyst Mother Redia Daughter Ceraria Metacercar Juveniles Adults Redia Definitive 1st intermidate 2nd host host intermidate Definitive host host (Human,cat (snails in fresh ,dog,tiger) water) (crab and (Human,cat, crayfish) dog,tiger) -Crayfish Crab melania snail
Life Cycle Metacercaria Adults Juveniles Adults Eggs Miracidum Sporocyst Mother Redia Daughter Redia Ceraria Definitive host (Human,cat ,dog,tiger) 1st intermidate host (snails in fresh water) 2nd intermidate host (crab and crayfish) Definitive host (Human,cat, dog,tiger) melania snail Crayfish Crab
Life Cycle Development in human Infection Stage metacercaria Mode 1eating raw crab or crayfish with Metacercaria 2 eating raw transport host,such as wild pig 3 drinking raw stream water
Development in human Life Cycle Infection Stage metacercaria Mode ① eating raw crab or crayfish with Metacercaria ② eating raw transport host, such as wild pig ③ drinking raw stream water