paralaban semifota

• Trematodes


  • Belong to Phylum Platyhelminthes "flatworms" (together with cestodes)
  • Leaf-like adults (except blood flukes)
  • All monoecious (except schistosoma species)
  • Possess spines and tuberculations
  • All possess two suckers (except heterophyes heterophyes, three suckers, genital sucker gonotyl)
  • DIAGNOSTIC STAGE: Eggs

  
• Operculated eggs


  Lid-like structure that opens to allow the larva to exit the egg
• Schistosoma spp. (Blood Flukes)


  • Most romantic parasite
  • Male: short and thick
  • Female: long and thin
• Mode of transmission for Schistosoma spp.

  Cercarial/skin penetration (swimmer's itch)
• Infective stage for Schistosoma spp.

  • Fork-tailed cercaria
  • Has lytic enzymes used to break skin
  • Survives only in freshwater, unchlorinated, no salt
• Diagnosis for Schistosoma spp.

  • Rectal Snips
  • Rectal biopsy
• Rectal Snips


  • Most sensitive and most invasive
  • Rectal snip sampling was done by scratching 3 replicates pieces from the anorectal fold (8cm from the anal canal) using sigmoidoscopy biopsy forceps
  • Rectal snip sampling should be done for negative or relapsed cases to exclude infection and confirm schistosomiasis clearance
• Schistosoma japonicum


  • Largest adult stage among blood flukes
  • Smallest ova
  • Habitat: Superior mesenteric vein of small intestine
  • Intermediate host: Oncomelania hupensis quadrasi
  • Ova: With recurved hook or knob, Ovoid, round, pear shaped
  • Katayama Syndrome/Fever: Happens 1-3 months after initial phase, Parasite in the mesenteric veins, Abrupt onset of fever, chills, muscle pain, headache, hepatomegaly, lymphadenopathy, dysentery

  
• Diagnosis for Schistosoma japonicum

  • Stool exam
  • Fairley's Test (Immunologic/Serologic test)
• Oral sucker


  For nutrition
• Ventral sucker


  Aka acetabulum, for attachment
• Operculated eggs


  Lid-like structure, open to allow the larva to exit the egg
• Blood flukes (Schistosoma spp.)

  • Male: short and thick
  • Female: long and thin
• Mode of transmission


  Cercarial/skin penetration (swimmer's itch)
• Infective stage


  Fork-tailed cercaria
• Cercariae


  Has lytic enzymes used to break skin, survives only in freshwater, unchlorinated, no salt
• Diagnosis


  1. Rectal snips

  2. Rectal biopsy
• Rectal snip sampling


  Scratching 3 replicates pieces from the anorectal fold (8cm from the anal canal) using sigmoidoscopy biopsy forceps
• Schistosoma japonicum


  • Largest adult stage among blood flukes
  • Smallest ova

  
• Habitat


  Superior mesenteric vein of small intestine
• Intermediate host


  Oncomelania hupensis quadrasi
• Ova


  • With recurved hook or knob, ovoid, round, pear shaped
• Katayama Syndrome/Fever


  Happens 1-3 months after initial phase, parasite in the mesenteric veins, abrupt onset of fever, chills, muscle pain, headache, hepatomegaly, lymphadenopathy, dysentery
• Diagnosis


  1. Stool exam

  2. Fairley's Test (Immunologic/Serologic test)
• Schistosoma mansoni


  • Smallest adult stage among blood flukes, male adult: prominent/coarse tuberculation, associated with spinal cord schistomiasis

  
• Habitat


  Inferior mesenteric vein of the colon
• Ova


  • Elliptical with lateral spine
• Schistosoma haematobium


  • Male adult: fine tuberculation, Urinary Bilharziasis, Egyptian hematuria, also linked with bladder carcinoma

  
• Habitat


  Vesical, prostatic, uterine plexuses of the venous circulation
• Ova


  • Elliptical with terminal spine
• Diagnosis


  Detection of eggs in urine for S. haematobium, best to collect urine from 12 pm to 3 pm
• LUNG FLUKE
• Paragonimus westermani


  • aka ORIENTAL LUNG FLUKE
• Mode of transmission


  Ingestion of uncooked or undercooked crabs with metacercaria
• Intermediate host


  1st Snail: Antemelania asperata and Antemelania dactylus

  2nd freshwater/mountain crab: Sundathelphusa philippina (Parathelphusa grapsoides)

  
• Cysteine proteases: involved in metacercarial excystment, tissue invasion
• Heavy infections


  Dry cough/chronic cough, blood-stained or rust-colored sputum (fishy odor)
• Erratic Paragonimiasis


  Can go to heart and brain
• Adult


  • Reddish brown, coffee bean-shaped, rounded anteriorly and slightly tapered posteriorly, found in pairs or threes in fibrotic capsules of the lung, adult firmly attached to the lung tissue, presence of spines on tegument (covering), intestinal ceca: wavy

  
• Ova


  • Golden brown, operculated, big and large, ridge: opercular shoulder, presence of abopercular thickening (opposite operculum)