1、Paragonimiasis,Intruduction,A kind of chronic disease caused by paragonimus westermani, paragonimus szechuanensis and several other related species Adult worm of paragonimus westermani inhabit lungs of the final host, causing cough, chest pain, rusty sputum and hemoptysis paragonimus szechuanensis c
2、ause subcutaneous nodules and masses Infected by eating raw crayfish and freshwater crab,Etiology,Morphology,Adult worm: they are monoecious, the reproductive organs are parallel, have two suckers Eggs: golden brown, ovate, operculate, the size is 80-12048-60m Metacercariae: round or ovate. Diameter
3、 300-400 m, 1-3 layers of cyst wall,Life Cycle,Man with adult worm to mature passing eggs into water 2-3months 21 days eating miracidiMetacercariafirst intermediate host(special snail)second intermediate host 3 months (crayfish and freshwater crab) cercaria,Epidemiology,Source of infection: humans m
4、ammals and other worm carriers, which can produce eggs Route of transmission: 1.The presence of the final host:patients and the infected mammals2.The presence of a large amount of 1st and 2nd intermediate host3.The habit of eating the freshwater crayfish and crab Susceptibility: every one is suscept
5、ive,Character of Epidemic,Widely distributed: Asia, Africa, America in our country, more than 21 provinces are involved in the infection It mainly occurs in summer and autumn North:the type of crayfish epidemicSouth:the type of freshwater crab epidemic,Pathogenesis and Pathogen,Process Caused by Juv
6、enile Worms,Metacercariae excyst in duodenum, and into abdominal cavity, the migrate cause mechanical lesions Penetrate diaphragms into pleural cavity to cause lung cyst The pathological change caused by pagumogonimus skjabin include :subcutaneous nodules mass, exudative pleurisy , liver lesion, and
7、 eosinophilia. The typical lesion are eosinophilous granulomas,Process Caused by Adult Worms,Inhabit lungs Migrate through lacerated foramen into cranial cavity, invade into the brain Invade into greater psoas muscle Migrate through intervertabral foramen into epidural cavityAll these causing space
8、occupying lesion,Process Caused by Eggs,The reaction is slight,Basic Pathological Lesion,The process are divided into three stages: Abscess stage: the worms migrate from intestine to lung, result in hemorrhage necrosis of the tissue, macrophages, eosinophils and neutrophile are aggregated causing eo
9、sinophilous abscess Cyst stage:the worms provoke a granuloma reaction that gradually proceed to develop fibroid encapsulation Fibrosis and scar stage:the internal material are excreted or absorbed, consequently proliferation of the fibrous tissues,Clinical Manifestation,Incubation period: 3-6 months
10、 The onset is insidious, most slight and moderate infections are asymptoms In severe infection, the clinical manifestations are complex,Clinical Manifestations,Systemic symptoms: chills, slight fever, weakness, headache, chest pain, night sweat. Some patients have urticaria and asthma. Eosinophilia
11、is common Respiratory symptoms: the involvement of the lung are characterized by: rusty sputum, chest pain, coughing, hymoptysis, expectoration, hydrothorax, eggs can be found in the sputum Abdominal symptoms: general abdominal pain, diarrhea, nausea, vomit, and hepatomegaly.asites, intestinal adher
12、ence and obstruction occur in severe infection,Clinical Manifestation,Nervous system symptoms: the symptoms are complicated due to the variation of the location of the worms: Brain: Intracranial hypertensionDamage of the brain tissueAbnormal stimulation of brain tissue:Inflammation Spine: dyscinesia
13、 and sensory disturbance below the ridden area of the spine,Clinical Manifestation,Subcutaneous nodules and masses: at any part of the body, mainly abdomen, chest and backside. Always migratory Other symptoms: Differentiation of manifestation between paragonimus westermani and pagumogonimus skjabin
14、are on page 227 of our textbook,Laboratory Findings,General examination: in blood routine test, WBC raise to 10-40 G/l, and more than 80% may be eosinophils. ESR fasten Pathogen examination: Sputum:eggs, eosinophils and Charcot-Leyden crystal may be found. The positive rate of finding eggs can reach
15、 90%Stool: the eggs come from sputum swallowed, the positive rate is 15-40%Biopsy of subcutaneous nodules and masses: typical eosinophilous granuloma with eggs, larvae and adult worm,Laboratory Findings,Immunological test:Intracutaneous testELISADot-ELISA and Weston blotIHA and RIA etc. X-ray Chest
16、examination:CT Brain vascular and spine photography,Diagnosis,Epidemiologic date:history of eating raw or pickled freshwater crab or crayfish Clinical manifestation: cough, rusty sputum, migratory subcutaneous nodules and massesepilepsy, headache and paralysis Laboratory findings:Finding eggs or wor
17、msImmunological test,Differential Diagnosis,Tuberculosis : tubercular pleurisy or peritonitis Brain tumor and other brain parasitosis Viral hepatitis,Prognosis,Because the species, the location and the degree of infection are different, the prognosis is difference. The prognosis are usually good The
18、 prognosis of cerebrospinal type is bad,Treatment,Pathogen Treatment,Praziquantel is the best choice of drug for the therapy of paragonimiasis Dose:25mg/kg, three times a day, for 2-3 days, the brain type need 2 times therapy, the interval is 7 days The other drugs for choice include: mebendazole:ef
19、ficient for p.skijabinibithionol,Heteropathy Treatment,Cough, chest pain: antitussive, analgestics Epilepsy: valium or luminal Intracranial hypertension: dehydrating agent Space occupying lesion: surgery operation,Prevention,Control of the source of infection:Treat the patients and domestic animal at the same time. Cut off the route of transmission:,
