P. westermani

• P. westermani is otherwise known as Oriental Lung Fluke
• Mode of transmission - Ingestion of raw/pickled crayfish or freshwater crab
• Infective Stage - Metacercariae
• 1st Intermediate Host - Snail: Brotia asperata

  2nd Intermediate Host - Sundathelpusa philippina
• Final Host - Man
• Habitat - Lungs
• Coffee-bean shaped body

  Paragonimus westermani
• Clinical features resemble Pulmonary tuberculosis

  Paragonimiasis
• Definitive diagnosis is based on the detection of characteristic egg on sputum or stool, or less frequently, aspirated from abscess or effusion

  Most basic and most readily available diagnostic tool

  • Disadvantage: Low sensitivity (37-88%)
  • Sputum concentration with 3% NaOH with repeated examinations up to 3x on different days
• • Combined with high index of suspicion
  • Lung parenchyma lesions which may be infiltrative, nodular, or cavitating
  • Disadvantage: Radiographic findings are non-specific

  CHEST RADIOGRAPH
• • Useful for Cerebral paragonimiasis
  • Characteristic finding: conglomerated, multiple ring-enhancing lesions with a “grape-cluster” appearance with surrounding edema


  CT or MRI
• PRAZIQUANTEL (25 mg/kg, three times daily, for 2-3 days)

  ● Drug of choice

  ● Breastfeeding should be avoided during and 72 hours after treatment
• • Originally used for Fasciola hepatica infection
  • Cure rate is comparable to Praziquantel


  TRICLABENDAZOLE
• BITHIONOL - Alternative drug to PRAZIQUANTEL and TRICLABENDAZOLE
• Most practical way to prevent infection is to avoid ingestion of raw or insufficiently cooked crabs and other crustaceans