Remember Me
forgot your password?

Protocol for Parasite Egg Identification in Faecal Samples in Parasitology Unit

Introduction

To diagnose gastro-intestinal parasites of ruminants, the parasites or their eggs/larvae must be recovered from the digestive tract of the animal or from faecal material. These should be subsequently identified and quantified. The following are the main tasks involved in this process:

· Collection of faecal samples


· Separation of eggs/larvae from faecal material, and their concentration
· Macroscopically examination of prepared specimens


· Preparation of faecal cultures


· Isolation and identification of larvae from cultures

Limitations of faecal examination in the diagnosis of gastro-intestinal parasitism.

(a) The demonstration of parasite eggs or larvae in the faeces provides positive evidence that an animal is infected but does not indicate the degree of an infection.

(b) The failure to demonstrate eggs or larvae does not necessarily mean that no parasites are present; they may be present in an immature stage or the test used may not be sufficiently sensitive.

Various factors can limit the accuracy and significance of a faecal egg count.

(a) There is a fairly regular fluctuation in faecal egg output.

(b) Eggs are not evenly distributed throughout the faeces.

(c) The quantity of faeces passed will affect the number of eggs per unit weight.

(d) The egg output is influenced by the season of the year (large infections may be acquired during rainy seasons).

 (e) An egg count often refers to the total number of eggs of a mixture of species, which differ widely both in their biotic potential and their pathogenicity.

(f) Eggs may not be detected due to low numbers of them or to a low test sensitivity.

Collection of faecal samples

Faecal samples for parasitological examination should be collected from the rectum of animal.

If rectal samples cannot be obtained, fresh Faecal samples may be collected from the pasture.

Several samples should be collected. Samples should be dispatched as soon as possible to a laboratory in suitable containers such as:

· screw cap bottles


· plastic containers with lids


· disposable plastic sleeves/gloves used for collecting the samples


· plastic bags

Each samples should be clearly labeled with animal identification ,date and place of collection.

Samples should be packed and dispatched in a cool box to avoid the eggs developing and hatching. If prolonged transport time to a laboratory is expected, the following may help to prevent the eggs developing and hatching.

(a) Filling the container to capacity or tightening the sleeve/glove as close to the faeces as possible. This is to exclude air from the container.

(b) Add 3% formal in to the faeces (5-20 ml, depending on the volume of faeces). This is to preserve parasite eggs. (N.B Formalin-fixed faeces cannot be used for faecal cultures.) When samples are received in the laboratory they should immediately be stored in the refrigerator (4 °C) until they are processed. Samples can be kept in the refrigerator for up to 3 weeks without significant changes in the egg counts and the morphology of eggs. SAMPLES SHOULD NEVER BE KEPT IN THE FREEZER.

Qualitative techniques for separating and concentrating eggs/larvae

1:Simple flotation method

2:Sedimentation technique (for trematode eggs)

1:Simple flotation method

Application

This is simple technique for use in initial surveys. It can be used in conjunction with the McMaster technique to detect low numbers of eggs.

Equipment

 

· Two beakers or plastic containers

· A tea strainer or cheesecloth

· Measuring cylinder or other container graded by volume

· Fork, tongue blades or other type of stirring rod

· Test tube (dry)

· Microscope

· Microslides, coverslips

· Balance or teaspoon

· Flotation fluid

Procedure:

 (A) Put approximately 3 g of faeces (weigh or measure the faeces with a precalibrated teaspoon) into container 1

 (B) Pour 50ml of floatation fluid into container 1

 (C) Mix the contents thoroughly with a stirring device (tongue blade fork).

 (D) Pour the resultant faecal suspension through a tea strainer or a double-layer of cheesecloth into container 2.

(E) Leave the container to stand for 10 minutes.

(F) Fill the  test tube with Faecal suspension up to full

 (G) Place the test tube in a test tube stand or rack.

 

 (H) Cover the test tube by a cover slip on top

(I) Mount the cover slip on micro slide for microscopic examination for egg /larvae identi fication

Sedimentation technique (for trematode eggs)

 

Application

This is a procedure to assess the presence of trematode infections.The procedure can be used to detect liver fluke (Fasciola) and Paramphistomum eggs.

Equipment

 

· Beakers or plastic containers

· A tea strainer or cheesecloth

· Measuring cylinder

· Stirring device (fork, tongue blade)

· Test tubes

· Test tube rack

· Methylene blue

· Microslide, coverslips

· Balance or teaspoon

· Microscope

Procedure

 (A) Weigh or measure approximately 3 g of faeces into container 1

 (B) Pour 40-50 ml of tap water into container 1

 (C) Mix (stir) thoroughly with a stirring device (fork,tongue blade).

 (D) Filter the faecal suspension through a tea strainer or double layer of cheesecloth into container 2.

 (E) Pour the filtered material into a test tube.

(F) Allow to sediment for 5 minutes.

 (G)Remove (pipette, decant) the supernatant very carefully

 (H) Resuspend the sediment in 5 ml of water

(I) Allow to sediment for 5minutes.

 (J) Discard (pipette, decant) the supernatant very carefully.

 (K) Stain the sediment by adding one drop of methyline blue

 (L) Transfer the sediment to a micro slide. Cover with a cover slip and examine under micro scope.

Quantitative techniques for separating and concentrating eggs/larvae:

The simplest and most effective method for determining the number of eggs or oocysts per gram of faeces is the McMaster counting technique

Application

This technique can be used to provide a quantitative estimate of egg output for nematodes, cestodes and coccidia. Its use to quantify levels of infection is limited by the factors governing egg excretion.

Equipment

· Beakers or plastic containers


· Balance


· A tea strainer or cheesecloth


· Measuring cylinder


· Stirring device (fork, tongue depressor)


· Pasteur pipettes and (rubber) teats


· Flotation fluid


· McMaster counting chamber


· Microscope

 

Procedure

 (a) Weigh 4 g of faeces and place into container 1.

 (b)Add 56 ml of  a floatation fluid.

 (c) Mix ( stir) the contents thoroughly with a stirring device (fork,tongue blade).

 (d) Filter the faecal suspension through a tea strainer or a double layer of cheesecloth into container 2.

 (e) While stirring the filtrate in container 2, take a sub sample with pasture pipette.

 (f) Fill the both slides of the McMaster counting chamber with the sub samples

 (g) Allow the counting chamber to stand for 5 minutes .

 (h) Examine the sub-sample of the filtrate under a microscope at a10x 10 magnification.

(i) Count all eggs and coccidia oocytes within the engraved area of both chambers.

 (j) The number of eggs per gram of faeces can be cal culated as followe:add the egg count of the two chambers togather

Multiply the total by 50. This gives the e.p.g. of faeces. (Example: 12 eggs seen in chamber 1 and 15 eggs seen in chamber 2 = (12 + 15) x 50 = 1350 e.p.g.)

 

Microscopical examination of prepared samples

 

The prepared samples on microslides from the simple test tube flotation method, the simple flotation method and the sedimentation method are examined under a microscope at the magnifications listed below.

 

Annex:

MAGNIFICATION LEVELS FOR EXAMINING PREPARED SAMPLES





Magnification



Parasites





10 x 10



Nematode and cestode eggs





10 x 40



Coccidia oocysts





10 x 4



Trematode eggs





Guideline to the interpretation of faecal egg counts in animals:

FAECAL EGG COUNTS IN ANIMALS





Parasite



Degree of infection (eggs per gram of faeces)





Light



Moderate



Heavy





CATTLE





 



Mixed infection



50-200



200-800



800+





 



Pure Haemonchus infection



200



200-600



600+





 



Pure Trichostrongylus infection



50-100



100-400



400+





 



Pure Cooperia infection



200-300



300-2500



2500+





SHEEP





 



Mixed infection



50-800



800-1200



1200+





 



Mixed infection with Haemonchus absent



300-800



800-1000



1000+





 



Pure Haemonchus



100-2000



2000-7000



7000+





 



Pure Trichostrongylus



100-500



500-2000



2000+





 



Pure Nematodirus



50-100



100-600



600+





 



Pure Oesophagostomum



100-800



800-1600



1600+





If possible guidelines for the interpretation of faecal egg counts should be established for each area/country/region according to different climatic zones, as the composition and pathogenicity of parasite populations may differ from area to area.

Appendix

Formulations for flotation fluids and other reagents for use in diagnostic tests.

FLOTATION FLUIDS

The preparation of three different flotation fluids is described below. Any one of them can be used, depending on the availability of reagents. However, the salt/sugar solution (3) gives the best results due to its high specific gravity.

Good-quality inexpensive salt and/or sugar that gives a clear solution should be used for the preparation of flotation fluids. For convenience, a stock supply can be prepared (preferably in a clear container so the amount of salt/sugar not in solution can be seen). The solution should be stirred thoroughly before use to ensure that it is saturated.





(1) Saturated salt solution





Sodium chloride (kitchen salt)



400 g





Water



1000 ml





Specific gravity: 1.200



 





(2) Saturated sugar solution





Sugar



Q.S.





Water



1000 ml





Specific gravity: 1.120-1.200



 





Add sugar until saturation, indicated by the presence of sugar crystals at the bottom of the container after stirring for 15 minutes. Stir well before use.





(3) Salt/sugar solution





Sodium chloride (kitchen salt)



400 g





Water



1000 ml





Sugar



500 g





Specific gravity:



1.280





Dissolve the salt in water (saturated solution). Add the sugar to the saturated salt solution. Stir until the sugar is dissolved.

OTHER REAGENTS FOR USE IN DIAGNOSTIC TESTS





(1) Physiological saline solution (0.9%).





Sodium chloride (kitchen salt)



9 g





Distilled water



1000 ml





Dissolve the salt in water





(2) Aqueous iodine solution.





Iodine re-sublimed crystals



10 g





Potassium iodide



50 g





Water



1000 ml





Dissolve the potassium iodide in the water.

Then add and dissolve the iodine crystals.





(3) Formalin 3% solution.





Commercial formalin (40% formaldehyde)



3 parts





Water



97 parts





 





NOTE. The commercially available 40% formaldehyde solution is regarded as 100% formalin.





 





(4) Sodium thiosulphate.





Sodium thiosulphate crystals



124.1 g





Water



1000 ml





Dissolve the crystals in water.

Reference:

The epidemiology, diagnosis and control of helminth parasites of ruminants: A Handbook Jørgen Hansen, DVM, PhD Animal Production and Health Division Food and Agriculture Organization Rome, Italy  Brian Perry, BVM&S, DTVM, MSc, DVM&S, MRCVS International Laboratory for Research on Animal Diseases Nairobi, Kenya ILRAD 1994  Published by the International Laboratory for Research on Animal Diseases, P.O. Box 30709, Nairobi, Kenya Printed by the International Livestock Centre for Africa Addis Ababa, Ethiopia ISBN 92-9055-703-1 .Chapter. 3. Techniques for parasite assays and identification in faecal samples,3.1-3.8

Dr.Kedar Karki
Dr.Kedar Karki.M.V.St. Preventive Veterinary Medicine CLSU Philippines Senior Veterinary Officer Central Veterinary Laboratory Tripureshwor Kathmandu Nepal
Rate this Article: 2 / 5 stars - 3 vote(s)
Print Email Re-Publish

Add new Comment



Captcha
0
1. bea (19:19, 12.08.2008)
The article is brief but most of the significant points I needed was supplemented. Nice!
+1
2. mehboob khan (03:07, 25.10.2008)
how can i get breaking news from net about vetarinary profession. and if i have a problem to diagnose a disease in an animal (bcz i am a veterinary studant , not a profeesional doctor) then how i can solve this problem.
0
3. Dr.Kedar karki (03:02, 14.08.2008)
Thanks for comment.this is just operational manual to perform the parasitological examination in faecal sample

  • Latest Medicine Articles
  • More from Dr.Kedar Karki

Endometriosis Infertility - it Can Be Treated

By: Randy Beckett | 15/11/2009
Endometriosis is a prevalent medical condition affecting millions of women worldwide. Irrespective of the race or ethnicity of women, the disease can occur at any stage in life. Although usually common in middle-aged women, endometriosis can also be found in young girls who have not yet reached puberty. A common...

Cure Severe Acne

By: James Tame | 15/11/2009
If you would like to know how to cure severe acne without having to use chemicals and special medical treatments that are not safe for your skin. There are natural method to cure severe acne, the natural acne treatments that you can use to cure severe acne without left over horrible scars. If acne is left too late it always develops in to a severe acne and becomes tricky to treat if you don't do anything about it.

Some Common Foot Problems

By: Brenda Williams | 15/11/2009
Our feet probably suffer more abuse than any part of our body and receive the least care. Most people devote far more time and money than caring for their faces than looking after their feet. But sometimes the feet decide to revolt and remind us of their presence. The results...

Buy Differin Drugs

By: caryfank | 14/11/2009
Differin is a drug that is used for treating acne vulgaris commonly known as pimples. This drug consists of adapalene compound, which is more similar to vitamin A, and treats acne. Differin or adapalene are under the group of drugs which are called as retinoids. The function of these differin or adapalene reduces the formation of acne or pimples by renewing the skin. It also reduces the formation of blackhead on the face. This drug is mainly manufactured by Galerma.

Buy Differin Drugs

By: faisal farrukh | 14/11/2009
There is nothing dangerous than buying a drug that does not serve you well or harm or leave with long-term effects. It is always worthy everything when you take all your time in researching for valuable information about the drug you want to buy for your skin problems.

Acne Treatment: Getting the Best Treatment

By: faisal farrukh | 14/11/2009
It is inconveniencing and sometimes disgusting to be under acne, wrinkles, or spots attacks, because they deny us the natural beauty we desire to have with our top skin layer.

Acne Creams: Know The Top Creams To Stop Acne

By: faisal farrukh | 14/11/2009
If you have made the decision of fighting or curing acne, winning will be on your mind, but you cannot win unless you go for the right acne creams.

Cryotherapy for Warts

By: bcured | 14/11/2009
If warts must be treated in pregnancy, cryotherapy appears to be the best choice. Cryotherapy involves application of nitrous oxide or liquid nitrogen to genital warts. The advantage of cryotherapy include ease of application and rapid destructive effect. However, this cure for warts is not always successful. More difficult warts may have to be surgically excised or burned off. Once surgical intervention or chemical acids are used one can expect a scar in that area.

Plastic as a Source of Environmental Pollution What is the Solution?

By: Dr.Kedar Karki | 21/10/2008 | Plastic Surgeries
"Plastics" derived their name from their properties to be molded, cast, extruded or processed into a variety of forms, including solid objects, films and filaments. These properties arise from their molecular structure. Plastics are polymers, very long chain molecules that consist of subunits (monomers) linked together by chemical bonds. The monomers of petrochemical plastics are inorganic materials (such as styrene) and are not biodegradable.

A Clinical-laboratory Investigation of Systemic Mycosis in Male Goats Due to Penicillium and Aspergillus Spp, in Mouldy Maize and Fodder in Kathmandu

By: Dr.Kedar Karki | 21/10/2008 | Nutrition
An outbreaks of a syndrome of unknown etiology associated with the feeding of moldy maize grain and green fodder to the male goat in a herd of 2000 meant for sale for Dashahara festival during the month of October-2008 in Kathmandu valley of which 52 goats suddenly became ill with symptoms of anorexia, apathy, diarrhea and ruminal stasis

A Review on Clinical Laboratory Outbreak of Sudden Death Syndrome in Broiler Chicken in Kathmandu Valley Nepal

By: Dr.Kedar Karki | 21/08/2008 | Nutrition
Incidence of this condition recorded was between 1.5 to 2.5% of the flock. The mean mortality due to sudden death syndrome was 1.3 - 9.6% and mortality was peak after 6 week of age. Post-mortem necropsies of birds affected by Sudden Death Syndrome were well-fleshed with edema and general pulmonary congestion.

Clinical Laboratory Outbreak of Sudden Death Syndrome in Broiler Chicken in Kathmandu Valley Nepal

By: Dr.Kedar Karki | 21/08/2008 | Diseases & Conditions
ABSTRACT: The incidence of sudden death of broiler birds above 40 days suddenly increased in the month of August 2008 in Kathmandu valley. Birds that were presented for post-mortem examination in Central Veterinary Laboratory Tripureshwor Kathmandu were usually found dead on their backs with wings out-stretched.

Protocol for Parasite Egg Identification in Faecal Samples in Parasitology Unit

By: Dr.Kedar Karki | 05/07/2008 | Medicine
To diagnose gastro-intestinal parasites of ruminants, the parasites or their eggs/larvae must be recovered from the digestive tract of the animal or from faecal material.

Bacterial Skin Diseases of Large Animals and Horses

By: Dr.Kedar Karki | 09/03/2008 | Diseases & Conditions
1. Dermatophiliosis a. Be able to recognize or list factors that contribute to infection of the skin with Dermatophiliosis.

Endemic Moist Eczematous Syndrome in Cattle a Laboratory Outbreak Investigation in Jhapa District of Nepal

By: Dr.Kedar Karki | 25/02/2008 | Diseases & Conditions
Abstract; An endemic hyperemic moist eczematous syndrome was reported in Cattle and Buffaloes in Jhapa district of Nepal during month of September after prolong spell of drought followed by heavy rainfall causing water logging total 56 cattle and buffalo were affected and out of which 12 animal died. Rest of ill animals were treated with 5%of Antidegnala liquor and Penta-sulphate. Straw and Skin samples revealed Penicillium sp.Fungus.

Cerebrospinal Nematodiasis in Goat: a Laboratory Epidemiological Outbreak Investigation and Use of Diethylecarbamazin in Treatment in Banke District O

By: Dr.Kedar Karki | 21/02/2008 | Diseases & Conditions
As adult seteria spp in cattle, Buffalo and microfileria from blood smears of affected goat confirmed the cerebrospinal nematodisease in goat in Nepal.

Submit Your Articles Free: Signup
Article Categories




Use of this web site constitutes acceptance of the Terms Of Use and Privacy Policy | User published content is licensed under a Creative Commons License.
Copyright © 2005-2008 Free Articles by ArticlesBase.com, All rights reserved. (0.06, 1, w1)