LUNG FLUKE Paragonimus westermani lung fluke

Paragonimus westermani is known as lung fluke that infects human cause paragonimiasis.
Infections are most common in eastern Asia and in South America.
Paragonimiasis present as a sub-acute to chronic inflammatory disease of the lung.
Discovered by Coenraad Kerbert in 1878

1. LUNG FLUKE DR. VEERENDRA MARAVI JR-2 , DEPT OF MICROBIOLOGY

2. CONTENTS INTRODUCTION HISTORY MARPHOLOGY GEOGRAPHICAL DISTRIBUTION EPIDEMIOLOGY LIFE CYCLE OF PARAGONIMUS WESTERMANI PATHOLOGY CLINICAL MANIFESTATION LABORATORY DIAGNOSIS TREATMENT CANTROL AND PREVENTION

3. INTRODUCTION Paragonimus westermani is known as lung fluke that infects human cause paragonimiasis. Infections are most common in eastern Asia and in South America. Paragonimiasis present as a sub-acute to chronic inflammatory disease of the lung. Discovered by Coenraad Kerbert in 1878

4. Scientific name: Paragonimus westermani Order: Plagiorchiida Phylum: Platyhelminthes Domain: Eukaryota Family: Paragonimidae Kingdom: Animalia

5. HISTORY Discovered in Brazil in 1850 by Diesing ;- “ Distoma Rude”. Naterer first detected the lung fluke in 1828. Cornerad Kerbert detected flukes in the lungs of a Bengal tiger in 1878 and named Distoma westermani , ( zoo manager G.F Westerman ) Both Manson and von Baelz in 1880 reported finding eggs in the sputum of humans. Yokogawa in 1915 and Nakagawai in 1916 completely described the life cycle. 1899, the name Paragonimus westermani has been used

6. Morphology ( Adult) The adult worm is hen egg shaped Size: 7.5 - 12 mm long, 4-6 mm broad and about 3-5 mm thick. Adults worms live in the lungs, usually in pairs in cystic spaces that communicate with bronchi. Its anterior end is slightly broader than the posterior end. The ventral sucker in situated near about the middle of the body. Life span of the adult worm is about 6 to 7 years The excretory vesicle is large and extends from the posterior extremity to the anterior region, dividing the body into two equal halves: unbranch intestinal caeca and Caudal region.

7. Morphology of P. westermani

8. Morphology ( Egg) Golden brown in colour oval in shape flattened opercula 80 -120 μ m by 50 -60 μm in size Contain an un segmented ovum surrounded by yolk cell

9. Human Pargonimiasis

10. Geographical Distribution Source:- WHO 2015 ‘a’

11. Epidemiology It is estimated that 20 million are infected with Paragonimus westermani It is endemic in China, Korea, Japan, the Philippines, and Taiwan Japan, Korea, Formosa, China, Manchuria, the Philippine Islands and India Infection is also found in parts of tropical West Africa, from the Congo and Nigeria, especially from Southern Cameron Rare in the US but it is found in Missouri

12. India : Paragonimiasis is endemic in North East states of India. Many cases are reported from Manipur with a prevalence of 6.7%. Earlier, P. westermani was thought to be the causative agent of paragonimiasis in Manipur. According to the recent studies, P. heterotremus may be the responsible for paragonimiasis in Manipur

13. Humans contract the infection through ingestion of raw, undercooked, pickled, or wine-soaked crabs or crayfish . Also become infected by the ingestion of uncooked meat from wild animals, such as wild boar.

14. The migrating larvae in this meat may pass through the intestinal wall and continue their developmental cycle when eaten. Raw juice from crushed crayfish used as a home remedy for the treatment of measles has been a significant source of infection and may be a cause of cerebral paragonimiasis in children .

15. Habitat: Adult worm live in respiratory tract (lung) of man. Definitive Hosts: Man and Domestic animals (usually host in Asia are the tiger & leopard) Intermediate Host: First Host: A fresh water snail of the genus Melania Second Host: A fresh water crayfish or a crab

16. Life cycle of Paragonimus westermani The eggs are excreted unembryonated in the sputum, or alternately they are swallowed and passed with stool. In the external environment, the eggs become embryonated , and miracidia hatch and seek the first intermediate host, a snail, and penetrate its soft tissues . Miracidia go through several developmental stages inside the snail :sporocysts , rediae , with the latter giving rise to many cercariae , which emerge from the snail. The cercariae invade the second intermediate host, a crustacean such as a crab or crayfish, where they encyst and become metacercariae . This is the infective stage for the mammalian host.

17. Human infection with P. westermani occurs by eating inadequately cooked or pickled crab or crayfish that harbor metacercariae of the parasite . The metacercariae excyst in the duodenum, penetrate through the intestinal wall into the peritoneal cavity, then through the abdominal wall and diaphragm into the lungs, where they become encapsulated and develop into adults (7.5 to 12 mm by 4 to 6 mm). The worms can also reach other organs and tissues, such as the brain and striated muscles, respectively. However, when this takes place completion of the life cycles is not achieved, because the eggs laid cannot exit these sites. Time from infection to oviposition is 65 to 90 days.

18. Infections may persist for 20 years in humans. Animals such as pigs, dogs, and a variety of feline species can also harbor Paragonimus westermani

19. Second intermediate hosts for Paragonimus spp. (Upper, left) Crab; (right); metacercaria. (Lower) Crayfish .

20. Mode of Infection- Eating raw, undercooked or pickled crustaceans such as crab or crayfish Spitting, a habit in Asian countries. Cultures that eat raw crustaceans.

21. Possible means of acquiring infection with Paragonimus spp.

22. PATHOLOGY When humans ingest raw infected crustaceans, larval flukes develop in the small intestine, penetrate the intestinal wall into the peritoneal cavity 30 minutes to 48 hours after excysting . They then migrate into the abdominal wall or liver, where they undergo further development. Approximately 1 week later, adult flukes re-enter from the abdominal cavity and penetrate the diaphragm to reach the pleural space and lungs . Flukes mature, a fibrous cyst wall develops around them, and then egg deposition starts 5 -6 weeks after infection. The symptoms of the early stages of this disease appear to be few with some people

23. PATHOLOGY The worms finally get into the lung parenchyma and induce acute exudative pneumonitis and haemorrhage . They gradually mature and are encysted, thereby producing zones of active inflammation with exudate and of collagenous fibrous tissue. The worms are found usually in pairs. When grown up, these worms are often found inside the bronchial lumen lined with bronchial epithelia of squamous metaplastic character . The cysts consist of the parasite and of dense collagenous connective tissue including various inflammatory cells and eosinophils

24. PATHOLOGY Once the parasite is in the lung or another organ, the worm stimulates an inflammatory response that eventually coats tissue. If worms enter the CSF of the spinal cord, it can result in partial or total paralysis. There have also been fatal cases of Paragonimiasis by infection of the heart. Cerebral cases may result in cerebral cysticercosis (fluid filled cysts surrounding the worm ). The adult worm , as it move around , cause lesions by mechanical damage. The eggs may couse granulomatous reaction which may soften to form cavities, the wall of which is compose of fibrous granuloma tissue ( Epithelioid cell, Lymphocyte, Plasma cell, eosinophils , Gaints cell and fibroblast.)

25. Clinical Manifestation Pulmonary paragonimiasis Chronic cough, Haemoptysis , Stimulating a case of bronchiectasis , Bronchitis . chest pain with dyspnoea and fever. Pleural effusion and pneumothorax are possible complications. others may remain asymptomatic for weeks to months between periods of hemoptysis. As the cysts rupture, a cough develops, with increased production of viscous blood-tinged sputum (rusty sputum, which may have a foul fish odor) with chest pain.

26. Paragonimus westermani egg in the lung ( crosssection ).

27. Cerebral Disease worms found in the brain usually contain eggs. migrate from ruptured lung cysts The worms eventually encapsulated cause necrosis within the brain tissue. May couse cerebral hemorrhage, edema, and meningitis. associated lung lesion or a history of lung disease. Symptoms include fever, headache, nausea, vomiting, visual disturbances, motor weakness, localized or generalized paralysis . May exhibit personality changes, possible disorientation, May decline in cognitive function. Depending on the central nervous system location.

28. May also include paraplegia, sensory loss, or vision problems Specific sites can include the cerebral cortex, cerebellum, basal ganglia, medulla oblongata, and spinal cord . When a worm dies, the lesion cavity becomes filled with necrotic material. Cerebral paragonimiasis can be difficult to differentiate from brain disease caused by other parasites

29. Paragonimiasis in Other Body Sites Ulcers or abscesses can also occur in the skin or subcutaneous tissue. Involvement of the mastoid area has been seen in P. africanus The skin is one of the common sites for ectopic paragomiasis may seen in children. lesion is amigratory subcutaneous nodule that appears on anterior , often migrating through the abdominal chestwall wall to the pelvic region or lower limbs Worm may invade any organ or tissue except bone.

30. Other body sites that have been infected include the breast, lymph nodes, heart, pericardium, mediastinum , kidneys, adrenal gland, omentum , bone marrow, stomach wall, bladder, spleen, pancreas, and reproductive organs. Ectopic lesions are usually caused by worm migration. Dissemination of eggs to other body sites can also be responsible for the extra pulmonary pathology

31. LABORATORY DIAGNOSIS Sample specimen Sputum Stool Gastric aspired Pleural fluid Washing Tissue material

32. Microscopic Examinations 1. Sputum examination: (1) Alkali digestive method (10%NaOH) (2) Direct sputum smear 2. Stool examination: (1) Alkali digestion (2)Sedimentation method (3) Direct faecal smear 3.Biopsy Materials by Staining Gimsa stains

33. Paragonimus eggs may be confused with Diphyllobothrium latum eggs, because of similarities in their size and shape. Paragonimus eggs have opercular shoulders and a marked thickening at the abopercular end. Photographs (upper) Drawings (lower) (A )Diphyllobothrium latum egg ( B) Paragonimus westermani egg

34. KEY POINTS—LABORATORY DIAGNOSIS The wet preparation can be examined using the 10× (low-power) objective; these eggs are large enough. The wet preparation should not be so thick that the eggs are obscured by normal stool debris. In light infections, multiple stool and sputum specimens may be needed before the eggs are detected. Not to add too much iodine to the wet preparation, or the eggs will stain very darkly. The sedimentation concentration method should be used; because the eggs do not float in the zinc sulfate flotation concentration method.

35. Immunological Test Non specific Test: 1.Intradermal skin test 2.complement fixation test Specific Test 1 . Indirect haemagglutination test 2.ELISA

36. Molecular Technique PCR technique Conventional PCR Real Time PCR DNA Hybridization n

37. Imaging Technology 1. Chest X Ray – Noduler,cystic and infiltrative in the middle and lower lungs similar to TB, Bronchiectasis 2. CT scan of Chest - pulmonary lesions

38. Treatment Praziquantel Oral, 1.Causes severe spasms and paralysis of the worms muscles 2. Not for pregnant women. A/E- Stomach pains, dizziness,fever , nausea, vomiting, headache 3. Better tolerated than Bithionol Bithionol- use is limited due to side effects Triclabendazole- If other drugs failed

39. CONTROL & PREVENTION Fully cook shellfish Heat water to 55° C for 5 minutes Freeze Fish - 20° C for 7 days -35° C for 15 hours Make spitting illegal Use Moluskicide to control snail population Maintain the hygiene and sanitation

40. References 1. Garcia LS. Diagnostic Medical Parasitology. Washington, DC: ASM Ptess ; 2019. 2. Sastry AS, Bhat S, Mishra D, Garcia LS, Sistla S. Essentials of Medical Parasitology. New Delhi, India: Jaypee Brothers Medical Publishers (P) Ltd; 2019. 3. CDC - Paragonimiasis [Internet]. Centers for Disease Control and Prevention; 2023 [cited 2023 Nov 23]. Available from: https://www.cdc.gov/parasites/paragonimus/index.html#:~:text=Paragonimus%20is%20a%20lung%20fluke,to%20the%20central%20nervous%20system.

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