Paragonimus westermani Gastrodiscoides hominis For MBBS Batch 2016

Paragonimus westermani & Gastrodiscoides hominis For MBBS Batch 2016 6 th August 2018 By: Dr Puneet Kumar Gupta Assistant Professor, Microbiology

• Oriental Lung fluke (flatworm) • Infects lungs of humans after eating an infected raw or undercooked crab or crayfish • Less frequent, but more serious cases when parasite travels to CNS • >30 Species-Infect human & Animals • >10 ------Infect humans 1/21/2022 2

• P. westermani (MC), – Primarily in Asia including China, Philippines, Japan, Vietnam, South Korea, Taiwan, &Thailand – India (Assam, Bengal, South India) • P. africanus-Africa • P. mexicanus - Central & South America – shellfish consumed raw or prepared only in vinegar, brine, or wine without cooking – Raw crabs or crayfish -used in traditional medicine practices in Korea, Japan, and some parts of Africa • P. kellicotti-Rare- US (Midwest) – ingestion of uncooked crawfish during river raft 1/21/2022 float trips in Missouri. 3

Morphology • Adult worm: – Egg shaped – Ant end broad> post end – 8 -12 X 4 -6 X 3 -5 mm (L X B X Thickness) – Ventral Sucker Middle of body • Life span: 6 -7 yrs • Habitat: Respiratory tract (Lungs) 1/21/2022 4

Morphology • Egg: – Golden brown – Oval with flattened opercula – 80 X 55 µm – Unsegmented ovum surrounded by yolk sac 1/21/2022 5

Life cycle 3 hosts • 1 Definitive: – Man & Domestic animals – Usual host Asia: Tiger & lepord – Reservoir: Feline • 2 Intermediate: – Fresh water Snail: Melania – Fresh water crayfish or crab 1/21/2022 6

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Pathogenicity • Mode of infection – Eating raw/improper cooked flesh of infected crayfish/crab – Drunken crab: Strips of raw crab meat soaked in alcohol • Infective stage: Metacercaria (adolescaria inside a cyst) • Portal of Entry: Digestive tract • Site of Localization: Lungs 1/21/2022 9

Disease • No symptom with light infection Pulmonary Paragonimiasis: • Acute syndrome with cough, abdominal pain, discomfort & low-grade fever occur 2 to 15 days after infection • Long-term infection may mimic bronchitis, bronchiectasis or tuberculosis – with Chronic cough with recurrent bout of blood-tinged sputum 1/21/2022 10

Disease • Coffee-colored or blood-tinged sputum, often accompanied by chest pain and/or shortness of breath • sputum clumps of eggs • Peripheral eosinophilia- early larval migration stages –intense • CXR: lobar infiltrates, coin lesions, cavities, calcified nodules, hilar enlargement, pleural thickening & effusions 1/21/2022 11

Disease • Ring-shaped opacities of contiguous cavities bunch of grapes -highly suggestive of pulmonary paragonimiasis 1/21/2022 12

Disease Extrapulmonary paragonimiasis: • CNS disease “grapebunch” findings, temporal & occipital lobes on CT brain • CNS involvement 25% of hospitalized patients – may be associated with Paragonimus-induced meningitis. – symptoms -headaches, seizures, and visual disturbances 1/21/2022 13

Disease • Ectopic lesions – Aberrant migration of flukes -any organ, including abdominal viscera, heart & mediastinum – Liver, spleen, intestinal wall, peritoneum, and abdominal LN & skin – Cerebral -highly endemic countries-children – Eosinophilic meningoencephalitis, seizures, or signs of space-occupying lesions 1/21/2022 14

Diagnosis • Eggs: Sputum, Stool M/E – Destroyed by ZN Stain – Yellowish brown – 80 -120 µm long X 45 -70 µm wide – thick-shelled with an obvious Shouldered operculum D/d D. latum egg: – Devoid of shoulder – Knoblike protrusion at other end 1/21/2022 (Absent in P. westermani) 15

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• Diagnosis Serologic tests – useful for early infections (prior to maturation of flukes) or for ectopic infections where eggs are not passed in stool – IHA & ELISA – Test negative 3 -4 months after successful treatment • Intradermal Test: Epidemiological Help – Immediate hypersensitivity test – Remains + ve long after recovery – Indicate past infection 1/21/2022 17

Diagnosis • Complement fixation test – Positive in Active infection – Test negative soon after death of worm • Radiology – X ray: • Abnormal Shadow (Nodular/cystic, Infiltrative) in middle or lower lung field • Presence of shadow of tunnels & burrows in lung – CT • PCR: Research use 1/21/2022 18

Diagnosis • Patient with CNS disease also have pulmonary infections • Trematode larva migrans: – P. skrjabini – often produces skin nodules, subcutaneous abscesses, or a type of creeping eruption reatment 1/21/2022 19

Treatment • DOC: Praziquantel: 5 mg/kg Per oral TDS X 2 d • Alternative: – Triclabendazole: 10 mg/kg Per oral OD or BD • For cerebral disease: Additional a short course of corticosteroids to reduce inflammatory response around dying flukes • Triclabendazole: CDC – Not in United States (Not approved by FDA) 1/21/2022 20

Prevention & Control • Never eat raw freshwater crabs or crayfish • Cook crabs & crayfish for to at least 145°F (~63°C) • Travelers advised to avoid traditional meals containing undercooked freshwater crustaceans 1/21/2022 21

Gastrodiscoides hominis • Caecum: 1 st reported in Indian patient suffering from Diarrhoea • India: Assam, Bengal, Bihar, Orissa • Vietnam, Phillippines 1/21/2022 22

Morphology • Adult worm: – Pyriform shaped – Ant end Conical post end Hemispherical – 5 -10 X 4 -6 mm – Bright pinkish color – Ventral Sucker – Large intestine (Caecum & Ascending Colon of definitive host: Man, pigs, monkey , rodents) – Pig & Monkey: Reservoir 1/21/2022 23

Morphology • Egg: – Greenish brown ovoid – Operculated – 150 X 60 -70 µm – Immature when laid 1/21/2022 24

Life cycle infect Egg---Passed in faceces water-Miracidium metacercariae in Vegatation & Snail Cercariae 1/21/2022 Rediae Penetrate aquatic gastropod Mollusc Sporocyst 25

Disease • Mucous diarrhoea & Oedema of intestinal wall: worm attachment to caecum & ascending colon with help of Large sucker 1/21/2022 26

• Eggs • D/d Diagnosis F. buski and F. hepatica (130 -150 X 60 -90 µm) Gastrodiscoides hominis may be slightly larger (130 -160 micrometers 1/21/2022 27

Thank you 1/21/2022 28

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