Helminthology Nematodes Nematodes Helminthology Angiostrongylus - - PowerPoint PPT Presentation

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Helminthology Nematodes Nematodes Helminthology Angiostrongylus - - PowerPoint PPT Presentation

Sep 13, 2023 402 likes •759 views

Helminthology Nematodes Nematodes Helminthology Angiostrongylus Angiostrongylus Terry L Dwelle Dwelle MD MPHTM MD MPHTM Terry L Classification of Nematodes Classification of Nematodes Subclass Subclass Order Order Superfamily

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SLIDE 1

Helminthology Helminthology – – Nematodes Nematodes Angiostrongylus Angiostrongylus

Terry L Terry L Dwelle Dwelle MD MPHTM MD MPHTM

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SLIDE 2

Classification of Nematodes Classification of Nematodes

Subclass Subclass Order Order (suborder) (suborder) Superfamily Superfamily Genus and Species Genus and Species Probable Probable prevalence in prevalence in man man

Secernentea Secernentea Strongylida Strongylida Metastrongyloidea Metastrongyloidea Angiostrongylus Angiostrongylus costraricensis costraricensis Thousands Thousands Angiostrongylus Angiostrongylus cantonensis cantonensis Thousands Thousands

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SLIDE 3

General Information General Information

► ►Geographic distribution

Geographic distribution

  • A

A costaricensis costaricensis – – Costa Rica, Honduras, El Costa Rica, Honduras, El Salvador, Mexico, Columbia, Brazil Salvador, Mexico, Columbia, Brazil

  • A

A cantonensis cantonensis – – China, Australia, Malaysia, China, Australia, Malaysia, Taiwan, New Caledonia, Fiji, Guam, Taiwan, New Caledonia, Fiji, Guam, Ponape Ponape, , Truk Truk, Tahiti, Hawaii, Japan, N Sumatra, C Java, , Tahiti, Hawaii, Japan, N Sumatra, C Java, India India

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SLIDE 4

General Recognition Features General Recognition Features

► ►Size

Size

  • A

A costaricensis costaricensis – – male 22 mm, female 42 mm male 22 mm, female 42 mm

  • A

A cantonensis cantonensis – – 17 17-

  • 25 mm

25 mm

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SLIDE 5

Adult Angiostrongylus cantonensis worms 1st stage rhabdiform larvae in rat feces A Colour Atlas of Tropical Medicine and Parasitology, 2nd edition, Yearbook Medical Publishers

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SLIDE 6

Life Cycle Life Cycle – – A A costaricensis costaricensis

► ►Definative

Definative host host – – cotton rat ( cotton rat (Sigmodon Sigmodon Hispidis Hispidis), man ), man

► ►Where the adults live in the body

Where the adults live in the body-

  • appendiceal

appendiceal mesenteric arteries mesenteric arteries

► ►Stage leaving the rat

Stage leaving the rat – – L1 L1 rhabdiform rhabdiform larvae larvae

► ►Intermediate host

Intermediate host – – slugs slugs

► ►Infectious stage for the host

Infectious stage for the host – – L3 L3 filariform filariform larvae via ingestion larvae via ingestion

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SLIDE 7

L3 filariform infectious larvae in a snail host Achalina fulica A Colour Atlas of Tropical Medicine and Parasitology, 2nd edition, Yearbook Medical Publishers

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SLIDE 8

Life Cycle Life Cycle – – A A costaricensis costaricensis

L3 filariform larvae

16-19days

Mesenteric artery

  • f the appendix

Cotton Rat Eggs

18 days

Intestinal wall L1 rhadiform larvae

24 days

GI lumen Feces Slug

Intermediate host

Mesenteric artery

  • f the appendix

Man Larvae eaten No patency

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SLIDE 9

Life Cycle Life Cycle – – A A costaricensis costaricensis

L3 filariform larvae

16-19days

Mesenteric artery

  • f the appendix

Cotton Rat Eggs

18 days

Intestinal wall L1 rhadiform larvae

24 days

GI lumen Feces Slug

Intermediate host

Mesenteric artery

  • f the appendix

Man Larvae eaten No patency

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SLIDE 10

Life Cycle Life Cycle – – A A costaricensis costaricensis

L3 filariform larvae

16-19days

Mesenteric artery

  • f the appendix

Cotton Rat Eggs

18 days

Intestinal wall L1 rhadiform larvae

24 days

GI lumen Feces Slug

Intermediate host

Mesenteric artery

  • f the appendix

Man Larvae eaten No patency

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SLIDE 11

Life Cycle Life Cycle – – A A costaricensis costaricensis

L3 filariform larvae

16-19days

Mesenteric artery

  • f the appendix

Cotton Rat Eggs

18 days

Intestinal wall L1 rhadiform larvae

24 days

GI lumen Feces Slug

Intermediate host

Mesenteric artery

  • f the appendix

Man Larvae eaten No patency

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SLIDE 12

Life Cycle Life Cycle – – A A costaricensis costaricensis

L3 filariform larvae

16-19days

Mesenteric artery

  • f the appendix

Cotton Rat Eggs

18 days

Intestinal wall L1 rhadiform larvae

24 days

GI lumen Feces Slug

Intermediate host

Mesenteric artery

  • f the appendix

Man Larvae eaten No patency

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SLIDE 13

Life Cycle Life Cycle – – A A costaricensis costaricensis

L3 filariform larvae

16-19days

Mesenteric artery

  • f the appendix

Cotton Rat Eggs

18 days

Intestinal wall L1 rhadiform larvae

24 days

GI lumen Feces Slug

Intermediate host

Mesenteric artery

  • f the appendix

Man Larvae eaten No patency

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SLIDE 14

Life Cycle Life Cycle – – A A costaricensis costaricensis

L3 filariform larvae

16-19days

Mesenteric artery

  • f the appendix

Cotton Rat Eggs

18 days

Intestinal wall L1 rhadiform larvae

24 days

GI lumen Feces Slug

Intermediate host

Mesenteric artery

  • f the appendix

Man Larvae eaten No patency

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SLIDE 15

Life Cycle Life Cycle – – A A costaricensis costaricensis

L3 filariform larvae

16-19days

Mesenteric artery

  • f the appendix

Cotton Rat Eggs

18 days

Intestinal wall L1 rhadiform larvae

24 days

GI lumen Feces Slug

Intermediate host

Mesenteric artery

  • f the appendix

Man Larvae eaten No patency

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SLIDE 16

Life Cycle A Life Cycle A costaricensis costaricensis

► ►Prepatent

Prepatent period period – – none none

► ►Patent period

Patent period – – none none

► ►Factors influencing transmission

Factors influencing transmission – – primarily primarily an infection of children 6 an infection of children 6-

  • 13 years old

13 years old

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SLIDE 17

Disease Characteristics Disease Characteristics

► ►Acute appendicitis

Acute appendicitis

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SLIDE 18

Diagnosis Diagnosis

► ►Clinical suspicion

Clinical suspicion

► ►Histology

Histology

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SLIDE 19

Treatment Treatment

► ►Surgery is curative (appendectomy)

Surgery is curative (appendectomy)

► ►May be a self limited course with complete

May be a self limited course with complete recovery recovery

► ►May respond to analgesics and

May respond to analgesics and corticosteroids corticosteroids

► ►Anti

Anti-

  • helminth

helminth therapy may worsen the therapy may worsen the symptoms symptoms

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SLIDE 20

Life Cycle Life Cycle – – A A cantonensis cantonensis

► ►Definitive host

Definitive host – – rat ( rat (rattus rattus), man ), man

► ►Where the adults live in the body

Where the adults live in the body – – pul pul arteries of rats, brain or eye of humans arteries of rats, brain or eye of humans

► ►Stage leaving the rat

Stage leaving the rat – – L1 L1 rhabdiform rhabdiform larvae larvae

► ►Intermediate host

Intermediate host – – land and aquatic snails land and aquatic snails and slugs and slugs

► ►Infectious stage for the host

Infectious stage for the host – – L3 L3 filariform filariform larvae via ingestion larvae via ingestion

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SLIDE 21

Achalina fulica Cipangopaludina chinensis Bradybaena similaris

A Colour Atlas of Tropical Medicine and Parasitology, 2nd edition, Yearbook Medical Publishers

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SLIDE 22

Life Cycle Life Cycle – – A A cantonensis cantonensis

L3 filariform larvae CNS Rat Eggs Respiratory tree L1 rhadiform larvae Gastro intestinal system Feces Snail or Slug

Intermediate host

CNS or Eye Man Larvae eaten No patency Lung Parenchyma Capillary bed

Ingestion or penetration of the foot pad 4 weeks L4 or early L5 larvae

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SLIDE 23

Life Cycle Life Cycle – – A A cantonensis cantonensis

L3 filariform larvae CNS Rat Eggs Respiratory tree L1 rhadiform larvae Gastro intestinal system Feces Snail or Slug

Intermediate host

CNS or Eye Man Larvae eaten No patency Lung Parenchyma Capillary bed

Ingestion or penetration of the foot pad 4 weeks L4 or early L5 larvae

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SLIDE 24

Life Cycle Life Cycle – – A A cantonensis cantonensis

L3 filariform larvae CNS Rat Eggs Respiratory tree L1 rhadiform larvae Gastro intestinal system Feces Snail or Slug

Intermediate host

CNS or Eye Man Larvae eaten No patency Lung Parenchyma Capillary bed

Ingestion or penetration of the foot pad 4 weeks L4 or early L5 larvae

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SLIDE 25

Life Cycle Life Cycle – – A A cantonensis cantonensis

L3 filariform larvae CNS Rat Eggs Respiratory tree L1 rhadiform larvae Gastro intestinal system Feces Snail or Slug

Intermediate host

CNS or Eye Man Larvae eaten No patency Lung Parenchyma Capillary bed

Ingestion or penetration of the foot pad 4 weeks L4 or early L5 larvae

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SLIDE 26

Life Cycle Life Cycle – – A A cantonensis cantonensis

L3 filariform larvae CNS Rat Eggs Respiratory tree L1 rhadiform larvae Gastro intestinal system Feces Snail or Slug

Intermediate host

CNS or Eye Man Larvae eaten No patency Lung Parenchyma Capillary bed

Ingestion or penetration of the foot pad 4 weeks L4 or early L5 larvae

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SLIDE 27

Life Cycle Life Cycle – – A A cantonensis cantonensis

L3 filariform larvae CNS Rat Eggs Respiratory tree L1 rhadiform larvae Gastro intestinal system Feces Snail or Slug

Intermediate host

CNS or Eye Man Larvae eaten No patency Lung Parenchyma Capillary bed

Ingestion or penetration of the foot pad 4 weeks L4 or early L5 larvae

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SLIDE 28

Life Cycle Life Cycle – – A A cantonensis cantonensis

L3 filariform larvae CNS Rat Eggs Respiratory tree L1 rhadiform larvae Gastro intestinal system Feces Snail or Slug

Intermediate host

CNS or Eye Man Larvae eaten No patency Lung Parenchyma Capillary bed

Ingestion or penetration of the foot pad 4 weeks L4 or early L5 larvae

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SLIDE 29

Life Cycle Life Cycle – – A A cantonensis cantonensis

L3 filariform larvae CNS Rat Eggs Respiratory tree L1 rhadiform larvae Gastro intestinal system Feces Snail or Slug

Intermediate host

CNS or Eye Man Larvae eaten No patency Lung Parenchyma Capillary bed

Ingestion or penetration of the foot pad 4 weeks L4 or early L5 larvae

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SLIDE 30

Life Cycle Life Cycle – – A A cantonensis cantonensis

L3 filariform larvae CNS Rat Eggs Respiratory tree L1 rhadiform larvae Gastro intestinal system Feces Snail or Slug

Intermediate host

CNS or Eye Man Larvae eaten No patency Lung Parenchyma Capillary bed

Ingestion or penetration of the foot pad 4 weeks L4 or early L5 larvae Prawns role??

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SLIDE 31

Angiostrongylus cantonensis Angiostrongylus cantonensis larvae Subarachnoid hemorrhage Larvae

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SLIDE 32

Diagnosis Diagnosis

► ►Clinical suspicion

Clinical suspicion

► ►Histology

Histology

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SLIDE 33

Treatment Treatment

► ►May be a self limited course with complete

May be a self limited course with complete recovery recovery

► ►May respond to analgesics and

May respond to analgesics and corticosteroids corticosteroids

► ►Antihelminth

Antihelminth therapy may worsen the therapy may worsen the symptoms symptoms

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SLIDE 34

Control Measures Control Measures

► ►Avoid the eating of undercooked fresh water

Avoid the eating of undercooked fresh water prawns, snails planarians, and slugs in prawns, snails planarians, and slugs in endemic areas endemic areas

► ►Rodent, snail, slug and planarian control in

Rodent, snail, slug and planarian control in endemic areas endemic areas