Diagnostic methods in parasitology

1. PARASITOLOGY :-
UNIT:- 3 ( DIAGNOSTIC METHODS IN PARASITOLOGY)
Techniques for the study of intestinal Nematodes (EGGS
COUNTING TECHNIQUES).
INTRODUCTION:-
 Nematodes infections give rise to larval stages that hatch in soil or
in the body tissues and may be diagnosed by using certain faecal
cultures methods to concentrate the larvae.
 In diagnostic methods of parasitology mostly applied techniques
are:-
1. Harada Mori Filter Paper strip Culture
2. Filter paper/ Slant culture techniques
3. Charcoal Culture
4. Baermann Techniques
5. Estimation of worm Burdens
6. Modified Stoll egg counting methods.

2. PARASITOLOGY:-
1.Harada – Mori Filter Paper Strip Cultures:-
• It help to detect infections of Hookworm,Strongloides and
Trichostronglyus spps. as well as to facilitate the specific
identification the Harada Mori Filter Paper Strip culture techniques
is very useful.
• Faecal materials to be cultured should be collected in sterile
containers and clinical specimens should not be refrigerated which
are not susceptible to cold temperature.
• Also caution must be exercised in handling the filter paper strip
itself, since infective strongloides larvae may migrate upward as
well as downward on the paper strip.

3. PARASITOLOGY:-
Procedure:-
1. Smear approximately 0.5 to 1 grams of faeces in the centre of a narrow strip of filter
paper.
2. To each 15 ml centrifuge tube, add about 3-4 ml of D/W
3. Identification of the specimen can be done by writing with a pencil on the filter paper
between the water line and the faecal materials.
4. Insert the filter paper strip into the tube so that the end of the strip (Cut so that the end
is slightly tapered) is near the bottom of the tube.
5. The water level should be slightly below the faecal mass. Caps are not required for the
tubes.
6. Maintain the tube in a rack at 24 to 28 deg.C and add water to the original level as
needed. Usually there is rapid evaporation over the first day or two and then the culture
become stabilize.
7. The capillary flow of the water up the filter paper strips keeps the faeces moist. Soluble
elements in the faeces are carried out the faecal mass and accumulates as a dark mass at
the top of the paper.
8. Tubes should be kept for approximately for about 10 days , but infective larvae may be
found any time after the fifth day. Daily checking is recommended.
9. A small amount of fluid may be withdrawn form the bottom of the tube with a glass
pipette ; larvae found will generally be alive and very active. They may be heat killed
within the tube or after removal on the slide; Iodine may also be used to kill the larvae.

4. PARASITOLOGY
10. Examine the larvae for typical morphological features to identify the presence of
hookworm, Stronglyoides or Trichostrongylus laevae.
ADAVANTAGE:-
 Can detect light infections with stronglyoides,hookworm or trichostrongylus.
 The larvae, after culture can be easily identified.
DISADVANTAGE:-
 Both pathogenic and free living larvae can grow in the system, hence these have to be
differentiated.
 Refrigerated specimens can not be used for culture as some larval species are destroyed
due to this methods.
 Caution is to be exercised as the larvae can cause infection.