Trema+P.wester Medical Helminthology PDF

1 Course: Medical Helminthology Lecture No. 7 Title: Trematodes By...

1 Course: Medical Helminthology Lecture No. 7 Title: Trematodes By Dr. Ahmed Abd Alfatah Ahmed Galander Ph. D of Medical Parasitology & Med. Entomology Faculty of Medical Laboratory Science - SUST E mail: [email protected] Mobile: 0122203753 Dr. Ahmed alande - 2024  2 Introduction  Trematodes are members of the phylum Platyhelminthes, which also includes Cestodes  Adult Trematodes, or flukes, may be found in the intestinal tract, bile-ducts, lungs or blood of humans.  Trematodes do not multiply within the human. Dr. Ahmed alande - 2024 General characters 3  Flat and leaf like, or occasionally globular.  The outer surface or tegument may have embedded spines.  Bilaterally symmetrical.  Lacking a coelom (body cavity).  Adults provided with two suckers:- Heterophyes (an accessory genital sucker)  Oral (open in the caecum)  Ventral sucker ( attachment)  Excretory system is based on the flame cell (protonephridium) Dr. Ahmed alande - 2024 Cont.1 General characters 4 Hermaphroditic organisms (except schistosomes). Oviparous. All have complicated aquatic life cycles D.H : Human and other animal I.H : snail and may need Fish or crabs as 2nd I.H With modified nerve System. Transmission by :- Ingestion of encysted Metacercaria.(free or embedded in tissue of 2nd I.H) Skin penetration by cecarial form. Dr. Ahmed alande - 2024  5 Dr. Ahmed alande - 2024  6 GUT Dr. Ahmed alande - 2024  GUT 7 Dr. Ahmed alande - 2024  Excretory 8 system Dr. Ahmed alande - 2024  9 Nerve system Dr. Ahmed alande - 2024  10 Classification  According to the habitat of Adults it classified into: 1. Liver flukes(C.sinensis, F.hepatica & F.gigantica). 2. Blood flukes (Schistosoma). 3. Lung fluke (P.westermani) 4. Intestinal flukes (F.buski & Heterophyes) Dr. Ahmed alande - 2024  11 Course: Medical Helminthology Lecture No. 8 Title: Paragonimiasis By Lung Fluke Worm Dr. Ahmed Abd Alfatah Ahmed Galander Ph. D of Medical Parasitology & Med. Entomology Faculty of Medical Laboratory Science - SUST E mail: [email protected] Mobile: 0122203753 Dr. Ahmed alande - 2024  12 Introduction A kind of chronic disease caused by Paragonimus westermani.  Adult worm of P. westermani inhabit lungs of the final host, causing cough, chest pain, rusty sputum and hemoptysis  Infected by eating raw crayfish and freshwater crab Dr. Ahmed alande - 2024 Morphology 13 1. Adult worm:  They are monoecious, the reproductive organs are parallel, have two suckers 2. Eggs:  Golden brown, ovate, operculate, the size is 80- 120×48-60m 3. Metacercariae:  Round or ovate. Diameter 300-400 m, 1-3 layers of cyst wall Dr. Ahmed alande - 2024  14 Dr. Ahmed alande - 2024  Life Cycle 15 Man with adult worm passing eggs into water 21 days to mature 2-3 months miracidi Eating Metacercaria first intermediate host(special snail) 3 months second intermediate host cercaria (crayfish and freshwater crab Dr. Ahmed alande - 2024  16 Dr. Ahmed alande - 2024  Epidemiology 17  Source of infection: Humans mammals which can produce eggs  Route of transmission: 1.The presence of the final host: patients and the infected mammals 2.The presence of a large amount of 1st and 2nd intermediate host 3.The habit of eating the freshwater crayfish and crab  Susceptibility: every one is susceptive Dr. Ahmed alande - 2024  Pathogenesis 18 1. Juvenile 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 include : 1. Subcutaneous nodules mass 2. Exudative pleurisy 3. Liver lesion with eosinophilia(typical lesion are eosinophilous granulomas) Dr. Ahmed alande - 2024 2. Adult Worms 19  Inhabit lungs 1. Migrate through lacerated foramen into cranial cavity, invade into the brain 2. Invade into greater psoas muscle 3. Migrate through intervertabral foramen into epidural cavity 19 3. Process Caused by Eggs  The reaction is slight Dr. Ahmed alande - 2024 Basic Pathological Lesion 20  The process are divided into three stages: 1. Abscess stage:  The worms migrate from intestine to lung, result in hemorrhage necrosis of the tissue, macrophages, eosinophils and neutrophile are aggregated causing eosinophilous abscess 2. Cyst stage:  The worms provoke a granuloma reaction that gradually proceed to develop fibroid encapsulation 3. Fibrosis and scar stage:  The internal material are excreted or absorbed, consequently proliferation of the fibrous tissues Dr. Ahmed alande - 2024 Clinical Manifestations 21  Systemic symptoms:  chills, slight fever, weakness, headache, chest pain, night sweat. Some patients have urticaria and asthma. Eosinophilia is common  Respiratory symptoms:  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 adherence and obstruction occur in severe infection Dr. Ahmed alande - 2024 Cont.1 Clinical Manifestations 22  Nervous system symptoms:  Symptoms are complicated due to the variation of the location of the worms:  Brain: Intracranial hypertension. Damage of the brain tissue. Abnormal stimulation of brain tissue. Inflammation.  Spine: Dyscinesia and sensory disturbance below the ridden area of the spine  Subcutaneous nodules and masses:  Occur at any part of the body, mainly abdomen, chest and backside. Always migratory Dr. Ahmed alande - 2024 Diagnosis 23  Epidemiologic date: History of eating raw or pickled freshwater crab or crayfish  Clinical manifestation: - Cough, rusty sputum, - Migratory subcutaneous nodules and masses. - Epilepsy, headache and paralysis  Laboratory findings: Finding eggs or worms Immunological test Dr. Ahmed alande - 2024 Laboratory Findings 24  Parastiological examination: 1. Sputum: Eggs, eosinophils and Charcot-Leyden crystal may be found. The positive rate of finding eggs can reach 90% 2. Stool: Eggs come from sputum swallowed, the positive rate is 15-40% 3. Biopsy of subcutaneous nodules and masses: Typical eosinophilous granuloma with eggs, larvae and adult worm are seen.  General examination: WBC raise to 10-40 G/l, and more than 80% may be eosinophils. ESR fasten Dr. Ahmed alande - 2024 Laboratory Findings 25  Immunological test:  Intracutaneous test  ELISA  Dot-ELISA and Weston blot  IHA and RIA etc.  Imaging Examination  Chest examination:  X-ray & CT  Brain vascular and spine photography Dr. Ahmed alande - 2024  26 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 Bithionol Dr. Ahmed alande - 2024 Prevention 27  Control of the source of infection: Treat the patients and domestic animal at the same time.  Health education.  Avoid eating raw fresh water crabs and crayfishes.  Avoid sputum and stool getting into water. Dr. Ahmed alande - 2024  28 Dr. Ahmed alande - 2024