Diagnostic Laboratory Section

DIRECT EXAMINATION

Microscopic examination

• Unstained smear - Procedure
  • It is possible to demonstrate the eggs or larvae of helminths, by the examination of a thin smear of emulsified faeces.
  • Place several drops of saline on a slide with an equal volume of feces
  • Mix the solution and feces together with a wooden applicator until the solution is homogenous
  • Smear the solution over the slide into a thin film
  • Place a cover slip over the smear
  • Examine the area of the slide under cover slip with the compound microscope.
  • The slide is investigated using a magnification of 10x and 40x.

• Merits
  • This method is quick.
  • Minimal equipment is needed.
• Demerits
  • It is effective only when the concentration of parasite stages is high.
  • It is frequently difficult to identify them since they are partially covered by debris.
  • Quantitative results cannot be obtained.

Intestinal schistomiasis / portal schistosomiasis

• Procedure
  • Collect the dung with mucus.
  • Place 2-3 drops of 4% KOH or 4% NaOH solution on a slide.
  • Take a little quantity of mucoid dung and mix it with the alkaline solution on the slide.
  • Keep the slide for some time so as to allow mucolysis to take place.
  • Spread the suspension evenly.
  • Place a coverslip and examine under low power objective of the microscope.

Result

• Egg of Schistosoma spindale will appear as spindle shaped / Napolean hat shaped with a terminal spine at one end.
• Egg of Schistosoma indicum appear as elliptical with a terminal spine at one end .