WEEK 1 LAB

• Specimens used for identification

  • Stool sample
  • Urine sample
  • Sputum sample
  • Tissue biopsy
  • Blood sample
  • Tissue aspirate
• Diagnosis of parasitic infection

  Suitable sample for recovery of parasites
• Habitat of parasites


  Gastrointestinal tract
• Specimen for intestinal parasites

  Stool sample
• Proper identification of parasites

  Based on microscopic examination
• Direct fecal examination


  1. Direct saline smear

  2. Lugol's iodine smear

  3. Kato-Katz smear

  4. Acid fast-stained smear
• Direct saline smear


  Detection of motile protozoan trophozoites
• Lugol's iodine smear


  Stains organelles of protozoa
• Kato-Katz smear


  Good for detecting eggs with thick shells
• Acid fast-stained smear


  Used for intestinal parasites
• Concentration methods


  1. Sedimentation method

  2. Floatation method
• Formalin-ether concentration technique


  Recovers helminth eggs and protozoan cysts
• Acid ether concentration technique


  Recommended for recovery of Trichuris, Capillaria, and trematode eggs
• Brine floatation


  Simple but can distort helminth eggs
• Zinc sulfate floatation


  Ideal specific gravity range to avoid distortion of parasites
• Stool sample characteristics


  Watery stool for trophozoite stage, formed stool for cyst stage
• Culture methods


  1. Harada Mori for Strongyloides and hookworm

  2. Robison's method for Entamoeba histolytica
• Urine sample


  For diagnosis of Trichomonas vaginalis and Schistosoma haematobium
• Sputum sample


  For recovery of Paragonimus westermani and Ascaris lumbricoides larvae
• Tissue biopsy


  For diagnosis of Trichinella spiralis, Taenia solium cysticercosis, and Leishmania
• Blood smears


  Thick smear for screening, thin smear for species identification
• Malaria parasites


  Plasmodium falciparum and Plasmodium vivax
• Microfilaria


  Can cause elephantiasis, e.g. Wuchereria bancrofti and Brugia malayi
• Hemoflagellates


  Leishmania in amastigote and trypomastigote forms
• Knott's concentration


  For recovery of microfilaria in cases of low microfilaremia
• Serological tests


  COPT for Schistosoma, antibody detection for malaria
• Tissue aspirate


  Liver aspirate for recovery of Entamoeba histolytica trophozoites
• Trypomastigote


  Recovered in the blood
• Knott's Concentration


  1. Request for light infections

  2. Need of more amount of sample for the recovery rate will increase

  3. For Microfilaria: 1 drop of Blood

  4. In cases of low microfilaremia, 1 mL of blood can be mixed with 10 mL of 2% formalin and then centrifuged

  5. The supernate is discarded and the sediment is studied

  6. Part of the sediment can be spread like a thin blood film and stained
• COPT (Schistosomes)


  • Specimen: Blood
  • Antigen and Antibody testing
  • Detection of Antibody
  • Abb: AB antigen or Antibody AntiGene (AB - AG)
  • Test kit contains antigen
  • (+) Directs to immunological test
  • (+) Malaria
• Biting habit: 10pm - 2am
• Liver aspirate (Amoeba)


  1. For the recovery of Amoeba

  2. Entamoeba histolytica trophozoites

  3. Not easy especially in cases when the submitted material is aspirated from the center of the abscess where there is necrosis. The best material for this purpose is aspirate coming from the margin or the wall of the abscess
• It is usually requested to rule out hepatic amebic abscess
• Duodenal aspirate (G.lamblia)


  1. String Test / Enterotest

  2. Patient allows to swallow capsule like material until it reaches to the duodenum and it will be left for 5 - 10 minutes and the string will be pulled

  3. The parasites clinging on the string are recovered

  4. For the recovery of G. lamblia
• Vaginal swab - T. vaginalis


  1. For the recovery of T. vaginalis

  2. Vaginal discharges
• Perianal swab - E.vermicularis & Taenia sp.

  1. In life cycle of E. vermicularis, the female worm migrates to the anus and hatch then releases eggs left on Perianal area

  2. Can cause Perianal itching or pruritus ani

  3. Enterobius gravid female migrates out through the anus at night time, and deposits eggs on the perianal skin

  4. Taenia spp. gravid segments can crawl out of the anus and in the process, ova are squeezed out of the segment and are deposited on the perianal skin
• Taenia saginata and Taenia solium


  • Tapeworm are release in the anus
  • Made of hundreds of proglottids (segments)
  • Strobila - Series of proglottids
• CSF


  1. N. Fowleri

  2. Pre - living

  3. It can survive outside the host but it can also infect human

  4. MOT: Acquire thru the nose and goes directly to the brain

  5. It causes Secondary Amebic Meningoencephalitis

  6. Parastrongylus larvae have been recovered
• Fecal specimen is best collected in clean, wide-mouthed containers made of waxed cardboard or plastic with a tight-fitting lid to ensure retention of moisture
• Strictly fresh specimen → for laboratory diagnosis