(flukes)

CLASS TREMATODA (FLUKES)  Characteristics

 Dorsoventrally

flattened EXCEPT Schistosoma  Have 2 suckers Oral and ventral suckers for attachment  Life cycle Egg – operculted ova EXCEPT for Schistosoma Larva Miracidium->sporocyst->redia-> cercaria->metacercaria adult

 Definitive

host: Man Harbors adult worm Infective stage: metacercaria EXCEPT Schistosoma

 Manner

of transmission Metacercaria ingestion Skin penetration of cercaria

Intermediate host  Harbors larval form  Have 2 intermedite host EXCEPT Schistosoma First intermediate host ALWAYS A SNAIL infective stage is miracidium Second intermediate host Infective stage: metacercaria Aquatic vegetation: Fasciola Fresh water fish: Chlonorchis Clams or crabs: Paragonimus

Liver Flukes 1. Fasciola hepatica  Sheep

liver fluke

 Habitat:

liver

 Transmission:

ingestion of contaminated aquatic vegetation

Manifestation: Abd.

Colic, obstructive jaundice, cough, vomiting

Diagnosis: Fecalysis Bachman

intradermal test Complement fixation test

 Treatment:  Bithionol

(drug of choice)  Emetine hydrochloride  Praziquantel  Prevention:  Mulluscicides  Sanitary

protection of waterbeds

2. Chlonorchis sinensis (Opistorchis sinensis) Chinese

liver fluke Habitat: liver Transmission: ingestion of raw or uncooked freashwater fish Manifestation: mild Progressive:

Irregular appetite, fullness of abdomen, diarrhea, edema, hepatomegaly Severe: cirrhosis, portal hypertension

 Diagnosis: Fecalysis Duodenal

 Treatment:  Prevention:

aspiration

chloroquine, praziquantel

thorough cooking of fish, sewage disposal

Intestinal Flukes  Fasciolopsis Giant

buski

intestinal fluke Habitat: duodenum and jejunum Disease: Fasciolopsiasis Transmission: Ingestion of contaminated aquatic vegetables Manifestations Toxic iarrhea, ascites, edema

 Diagnosis: History

and PE Fecalysis  Treatment:

Praziquantel

 Prevention Thorough

washing of vegetables Avoid water chestnuts in infected waters Prohibit use of night soil

Lung Fluke  Paragonimus

westermani

Oriental

Lung Fluke

Habitat:

lung

Disease:

Paragonimiasis

Transmission:

eating freshwater crabs

 Manifestations: Productive

cough, occasionaly hemoptysis Chest pain, night sweats, abdominal pain, diarrhea, epilepsy  Diagnosis:  Chest

xray  Sputum exam  Fecalysis  Complement fixation test  Treatment:

Praziquantel

Blood Flukes  Schistosomes Dioecious Always Three

in copula, “romantic parasite”

species

Schistosoma

japonicum Schistosoma hematobium Schistosoma mansoni

Schistosoma mansoni  Manson’s

blood fluke

 Habitat:

inferior mesenteric plexus rectum  Disease:

Bilharziasis Intestinal schistosomiasis

 Intermediate

host

Snail:

Biomphalaria, Australorbis Eggs: non-operculated, with lateral spine Cercaria has forked tail

 Diagnosis:

fecalysis  urine

Schistosoma hematobium  Vesicle

blood fluke

 Habitat:

vesical and pelvic plexus of venous circulation

 Disease:

urinary bilharziasis

 Intermediate

host:

Snail:

Bulimus, Planorbarius, Physopsis Eggs: non-operculated, with terminal spine Cercaria: forked tail  Diagnosis:

urinalysis  fecalysis

Schistosoma japonicum  Oriental

blood fluke

 Habitat: superior

intestine

 Disease:

mesenteric veins of small

Oriental schistosomiasis

 Intermediate

host:

Snail:

Oncomelania quadrasi Eggs: with abbreviated spine Cercaria: forked tail  Diagnosis:

fecalysis only

Clinical manifestations  Dermatitis:

Swimmer’s itch

 Diarrhea,

splenomegaly, lymphadenopathy

 Hematuria,  Headache,

coma

urethral obstruction disorientation, amnesia,

Treatment: Praziquantel Prevention: Proper

waste disposal molluscides

Quiz Time Please get 1/8 paper

1. Paragonimus westermani A. liver fluke C. intestinal fluke B. lung fluke D. blood fluke

2. Definitive host of trematodes A. pigs C. cow B. man D. snail

3. Synonymous with Trematodes A. tapeworm C. hookworm B. flukes D. roundworm