Lung Fluke (Paragonimus westermani) PDF

Lung Fluke Francis Ian L. Salaver, RMT, MD  Classification Based on Habitat Blood flukes Liver flukes Intestinal flukes Lung fluke Paragonimus westermani  Paragonimus westermani Oriental lung fluke Infective stage: Metacercaria Diagnostic stage: Unembryona...

Lung Fluke Francis Ian L. Salaver, RMT, MD  Classification Based on Habitat Blood flukes Liver flukes Intestinal flukes Lung fluke Paragonimus westermani  Paragonimus westermani Oriental lung fluke Infective stage: Metacercaria Diagnostic stage: Unembryonated ovum First intermediate host: Snail (Antemelania asperata) Second intermediate host: Crustaceans (crabs and crayfishes) Sundathelphusa philippina Second intermediate host  Description of the diagnostic stage Yellowish brown Operculated Unembryonated Thickened posterior end (abopercular end) Seen in sputum or stool (if the person is swallowing his sputum)  Operculated Thickened posterior end Fasciola/Fasciolopsis/Echinostoma eggs: posterior ends are not thickened Fasciola/Fasciolopsis/Echinostoma eggs: posterior ends are not thickened  Paragonimus Adult The body is elliptic, dorsoventrally it is flattened, reddish-brown in color It looks like half a peanut or coffee bean shaped The ventral sucker is located in the central position of the body. Adult is coffee-bean shaped Paragonimus Adult Oral sucker Unbranched intestine Ventral sucker is at the midline Ventral suckers of other trematodes are found near the oral sucker Paragonimus Adult Uterus _____ ovary ____ testes Vitellaria is up to the tail  Clinical presentation Classical feature of Paragonimiasis is: Persistent chronic cough associated with thick brownish red sputum (due to the presence of adult and ova), fever and myalgia Sometimes accompanied with blood (hemoptysis) – that’s why mistaken as TB Symptoms and signs mimic those of tuberculosis, and paragonimiasis should always be suspected in patients with tuberculosis who are non-responsive to treatment.  Clinical presentation Classical feature of Paragonimiasis is: Physical examination of the chest often reveals normal findings and patient generally appears well Pleural effusion and pneumothorax are possible complications (depending on the damage caused by the worm on the lungs)  Pathogenesis In the lungs, Paragonimus adult provoke granulomatous reaction that leads to the formation of capsule/cyst Within the cyst is blood-tinged purulent materials containing eggs  Clinical presentations Flukes the miss the lungs due to the circuitous route produce extrapulmonary symptoms due to granuloma or cyst or abscess formation Muscle Abdominal organs and liver Genitals Brain Heart Lymph nodes Paragonimus westermani Worm traverses the intestinal worm and escapes into the peritoneal cavity Wanders around the peritoneal cavity and embeds itself in the abdominal wall for days The parasite the returns to the coelom then migrates towards the diaphragm and pleural cavity 65-90 days of development in humans  Diagnosis Sputum is the recommended sample Stool can also be used as a diagnostic sample Sputum may reveal presence of egg and sometimes adult KEEP IN MIND: Acid fast staining ___________________  Treatment and Prevention Praziquantel Pregnancy??? Restriction from physical and occupation related activity for at least 2 hrs is recommended cause drug causes pyrexia, urticaria, abdominal discomfort, nausea, dizziness and headache Bithionol Prevention Proper human waste disposal Eating sufficiently cooked crab and crayfish Health education and promotion