Medical parasitology : study of parasites that infect human, diseases caused by them, clinical picture, their diagnosis, treatment and prevention as well as controls. It involves  drug development, epidemiological studies and study of zoonoses. To know various terms related to parasitology. To know about general parasites and parasitic infections. To get knowledge about laboratory diagnosis and its importance. To gain idea about general epidemiological aspects of parasites that affect human. Apply basic methods of specimen collection , preservation and processing in lab. To prevent ourselves from these infections and apply control measures.

1. MEDICAL
PARASITOLOGYLABORATORY
PresentedTo :
Mr.TapeshwarYadav (Sir)
(teacher/mentor)
Department of Laboratory Medicine,
Nobel College of Medical Sciences,
Kathmandu, Nepal
Presented By : Group H
-Moona
-Yuyasha
- Renuka
- Rohit
- Akshana

2. Preface
It is a golden opportunity for us to work on this
presentation titled as “PARASITOLOGY” to enhance
our speaking and presenting skills under the faculty
of BSc.MLT in Nobel College.The basic objective of
presentation is to gather knowledge about various
topics emphasizing on our course contents.
This presentation includes explanation on different
laboratory diagnosis, treatment, control of parasitic
diseases.

3. Acknowledgement
For any project, essential requirement is correct
guidance and references. We are very thankful to
Mr.TapeshwarYadav sir who provided us this
opportunity and motivation to gain knowledge
through this presentation. We have got knowledge
about the way to search information, filter them and
utilize various resources for gathering information.
Some of the sources are: google scholar, slide share,
wikipedia,etc.

4. CONTENTS
 OBJECTIVES
 SCOPE AND IMPORTANCE
 DEFINITIONS
 RELATIONSHIP OF PARASITES
 CLASSIFICATION OF PARASITES
 MODE OFTRANSMISSION
 SAMPLE COLLECTION
 DIFFERENTTESTS
 GENERAL STAINS ANDTHEIR PURPOSES
 PREVENTION AND CONTROL

5. Scope And Importance
To provide knowledge on parasitic infections,
their diagnosis , prevent and control them
Know the lifecycle of specific parasites and
identify important parasitic agents affecting
human health
Be able to prepare reagents necessary for
parasitological laboratory test
Apply necessary procedures for diagnosis of
parasites in laboratory

6. OBJECTIVES
 To know various terms related to parasitology.
 To know about general parasites and parasitic
infections.
 To get knowledge about laboratory diagnosis and
its importance.
 To gain idea about general epidemiological aspects
of parasites that affect human.
 Apply basic methods of specimen collection ,
preservation and processing in lab.
 To prevent ourselves from these infections and
apply control measures.

7. Definitions
 Parasitology: Scientific study of parasites, their hosts
and relationship among them.
 Father of parasitology : Francesco Redi
 Medical parasitology : study of parasites that infect
human, diseases caused by them, clinical picture, their
diagnosis, treatment and prevention as well as
controls.
It involves drug development, epidemiological
studies and study of zoonoses.
 Parasites : organism which depends upon host
eg: Plasmodium vivax

8.  Vector : living organism that carries a
disease-causing organism to new hosts
 Host : organism on which
parasite is depended.
eg: human beings
2 types:
 Definitive host :Host in which the parasite
reaches maturity and reproduces sexually.
 Intermediate host: Host in which a parasite
undergoes development but not sexual.

9. Some relationships
 Symbiosis: living together where either one
or both are benefitted while none is harmed
 Commensalism: one symbionts is benefitted
other is unaffected
 Mutualism: both symbionts are benefitted
 Parasitism: one symbiont is benefitted
whereas the next is damaged

10. PARASITE DISEASE
Plasmodium vivax Malaria
Solid transmitted helminths
Roundworm (Ascaris) Pnemonitis, intestinal obstruction
Whipworm (Trichuris) Blood diarrhoea, rectal prolapse
Hookworm (Ancylostoma and Necator ) Coughing, wheezing, abdominal pain
and anaemia
Schistosoma Renal tract and intestinal disease
Filariae Lymphatic filariasis and elephantiasis
Trypanosoma cruzi Chage diseases (cardiovascular)
Leishmania Cutaneous, mucocutaneous and visceral
leishmaniasis

12. FILARIASIS

18. Classification of parasites
 Protozoa:
Unicellular organism.
Eg: Plasmodium spp., the
protozoan parasite which
causes malaria
 Helminthes:
Multicellular organisms
and intestinal worms
(helminths) such as
 Schistosoma spp.,
 Wuchereria bancrofti,
 Necator americanus
 Taenia spp. (tapeworm)

19. PROTOZOA
 Unicellular eukaryotic microorganism
 Lack capability for photosynthesis
exc. Euglena
 Heterotrophic mode of nutrition
 Have indefinite shape and size
 Able to move independently by flagellum or cilia
(9+2) arrangement
 Moist habitat
 Study: protozoology

21. Protozoan diseases
Protozoa Diseases
 Giardia lamblia
 Leishmania tropica
 Leishmania donovani
 Entamoeba histolytica
 Plasmodium vivax
 Cryptosporidium parvum
 Trichomonas vaginalis
 Giardiasis
 Cutaneous leishmaniasis
 Kala-azar(visceral leishmaniasis)
 Amebic dysentery
 Malaria
 Cryptosporidiasis
 Vaginal trichomoniasis

22. Helminths
 Parasitic intestinal worms
 Bilateral symmetry
 Lacks digestive system
 Reduced nervous system
 Complex reproductive system( produce large no. of eggs)
 Means of locomotion is reduced or complete lacking

25. Nomenclature of parasites
 Binominial nomenclature
 Protozoa:
1. Sacromastigophora: Entamoeba histolytica, Giardia lamblia
2. Apicomplexa: Plasmodium vivax, P. malaria, P. falciparum
3. Ciliophora: Balantidium coli
4. Microspora: Enterocytozoon bieneusi, E. hellam,
Encephalitozoon cuniculi
 Platyhelminthes :
1. Cestoda: Diphyllobothrium latum, Taenia solium
2. Trematoda: Schiotosoma mansoni, S. japonicm,etc
3. Nemathelminthes: Ascaris lumbricoides

26. PARASITIC INFECTION
 An infection caused or transmitted by parasites
Source of infection
 Contaminated water
 Eggs containing food ingestion
 Arthropods bites
 Penetration of intact skin or mucuos membrane

27. Mode of transmission
MODE OFTRANSMISSION DISEASES
FAECAL-ORAL ROUTE , INGESTION Ascaris, Balantidiasis, Giardia,Taenia,
Cryptosporidiasis,Cyclospora, Fasciola,
VECTOR BORNE Kissing and hugging: Trypanosoma
Mosquito: Plasmodium, Wuchereria
Sand fly: Leishmania
Tsetse fly: Trypanosoma
SEXUAL CONTACT Entameoba, Giardia,Trichomonas
INHALATION Acanthameoba, Enterobius, Naegleria
CONTACT OF SKIN(PENETRATION) Ancylostoma, Necator, Schistosoma
CONTACT OF EYES(PENETRATION) Acanthamoeba

28. Faecal-oral route

29. General Classification of
parasites
 Ecto parasite: lives outside the host body
 Endo parasite: lives inside host body (blood, tissues,
body cavities, digestive tract)
 Temporary parasite: visit host for short time
 Permanent parasite: throughout whole lifespan
 Facultative parasite: on parasites when
opportunity arise
 Obligatory parasite: only on living host body
 Wandering parasite: at place where it cant live
 Occasional parasite: attacks on unusual host

30. Plasmodiumspp.

33. Tests
Stool
physical
consistency
Color and
odor
Quantity
Mucus
Chemical
Ph
Reducing
substances
Microscopic
Leukocytes
RBCs
Ova and
parasites
Meatfibres,
musclefibres
fat
Urine
Physical
Color and
odor
Turbidity
Specific
gravity
pH
Chemical
Protein
Glucose
Ketones,
nitrites
Urobilinogen
Bilirubin
Blood
microscopic
RBCs,WBCs
Epithelial
cells
microorganis
ms
Blood
Thin smear
Thick smear

34. INSTRUMENTS USED IN LAB

35. Sample Collection
1. The amount should be sufficient (4.0ml)
2. It should be collected in a non-absorbtive container
3. Stool sample should be examined as soon as
possible
4. Sample should not be left exposed to air which
leads to drying of stool
5. Stool mixed with urine should never be accepted
for investigation (urine destroys trophozoite forms
of parasites
6. While making smears, sample should be taken
from well inside formed stool and from mucus or
blood stained portions of loose stool

36. PHYSICAL
COLOR
Normal color - presence of stercobilinogen
- light or dark brown
Abnormal stool colour seen in different disease condition
- Black : bleeding from upper gastrointestinal tract tumors
- Brighter : bleeding from lower gastrointestinal tract
- Blood and mucus : amoebic dysentery
- Clay coloured :post hepatic jaundice obstruction to the flow of
bile to intestine(biliary obstructions)
- Yellow or yellowish green – diarrhoea
- Maroon or pink –due to tumors, haemorhoids,tissue or
inflammatory processs from lower gastrointestinaltract

37. ODOR
 The normal sample may smell offensive but not excessively
 foul, other can be described foul sour
 Foul odor caused by the undigested protein and by
excessive
 intake of carbohydrate
Offensive : amoebic dysentery
 Nil : bacillary dysentery
QUANTITY
Normally, there is 100 to 200 gm / day
Many disorders cause large bulky stools even in people who
Don’t eat a lot. Some gastrointestinal order also cause poor
food breakdown and absorption which leads to large, bulky
stools

38. CONSISTENCY
Normal stool is well formed .
 Abnormal stool consistency seen in different physical and
pathological condition .
Stools may be loosely formed stools, Watery stools, Thin
stools, Dry and hard stools, Putty like stools,
Small round hard stool(habitual constipation),
Pasty stools, diarrhoeal stool are watery,
 Steatorrhea stool are large in amount, forthy, foul
smelling
Constipated stools are firm and may be spherical masses
Ribbon like stool

39. MUCUS
 Mucus is not present in normal stool .
 Seen in amoeba of Giardia lamblia .
 when urea gets high than the normal mucus can be seen in
stool.
 It is also present in carcinoma condition.
 Pure mucous ie. translucent gelatinous material clinging to
the surface of stool.
This may be seen in severe constipation, mucous colitis ,
excessive staining of stool, emotionally unstable patient
 Mucus and diarrhoea with microscopically patient with RBCs
and WBCs is seen in bacilliary dysentary, ulcerative colitis,
intestinal tuberculosis, ameobiasis, enteritis, acute diverticulis,
ulcerating malignancy of the colon

41. CHEMICAL
Stool pH:
 This depends upon the dietary intake.
 Normally, slightly acidic or alkaline pH (7.0 to7.5)
 Alkaline pH :
 Colitis
 Villous adenoma
 Diarrhoea
 Antibiotic therapy
 Acidic pH:
 Fat and carbohydrate mal-absorption
 Disaccharidase deficiency

42. Reducing substances
 Glucose, fructose, galactose,etc are reducing
substance
 Lactose intolerance may occur after a prolonged
episode of viral gastroenteritis
 Fructose not absorbed can cause a positive test for
reducing sugar in stool
 Reducing subs. are reported as:
Negative –this is the normal result and means that the
body is digesting and absorbing sugars properly.
Positive- this means these are substances in the stool
that can act as reducing agents i.e. there are forms of
sugar in the stool that have not been absorbed by the
body

43. MICROSCOPIC
It includes
 Presence of leukocytes
 Presence of RBCs
 Presence of ova and parasites
 Presence of meat fibers and muscle fibers
 Presence of fat

44. 1. Presence of leukocytes
 Normally there are no WBCs
 Increase no of WBCs in stool
 Bacillary dysentery
 Chronic ulcerative colitis
 Shigellosis
 Salmonella E.coli diarrhoea
 Fistula of anus or rectum
 Localized abscess
 WBCs may appear in
typhoid
Absence of WBCs seen in
some of the diarrhoeal
condition
‐ Cholera
‐ Viral diarrhoea
‐ Drug induced diarrhoea
‐ Amoebic colitis
‐ Non-invarsive diarrhoea
‐ Parasitic infestation

45. 2. Presence of RBCs in the
stool
 Blood in the stool can be
 Bright red: from the bleeding in the lower GI tract
 Maroon in color
 Black & tarry: from bleeding from the upper GI tract
 Occult (not visible to naked eye)
Causes of blood in stool
 Hemorrhoids
 Cancer
 Dysentry

46. 3. Ova and parasites
 Normally there are no parasites or eggs in the stool
sample
 Multiple stool sample are needed to rule out parasitic
infestation at least three consecutive days.
 An abnormal results means parasites or eggs are
present in stool such infections include
- Roundworms: Ascaris lumbricoides
- Hook worms: Necator americanus
- Pinworms : Enterobius vermicularis
- Tapeworms: Taenia solium, Diphyllebothrium latum
- Protozoa : Entamoeba histolytica, Giardia lamblia

47. 4.Presence of meat and muscle
fibers
 Their presence show some defects in the digestion.
 Increased amount of meat fibers are found in :
 Mal-absorption syndrome
 Pancreatic functional defect like cystic fibrosis
5. Presence of fat
The fat in the stool shows the possibility of :
 Mal-absorption syndrome
 Deficiency of pancreatic digestive enzyme
 Deficiency of bile

48. Serodiagnosis
 Serological test becomes positive only in invasive amoebisis.
 Various serological tests done include :
 Indirect Hemagglutination (IHA)Test:
Serum with antibody titer of 1:256 or more by IHA Is diagnostic
of amoebic hepatitis.
 Latex agglutination test
 Enzyme-linked immunosorbent assay (ELISA):
 Commercially available tests that use ELISA to detect
 Entamoeba antigens (E. histolytica)
 Greater sensitivity than microscopic test

49. STOOL CULTURE
 It is a sensitive method in diagnosinf chronic
and asymptomatic intestinal amoebiasis.
 Media used for stool culture:
 Boeck and Drbohlav media
 NIH polygenic media
 Craig’s medium
 Nelson’s medium
 Robinson’s medium

50. Faecal Occult Blood Test
 Generally, stool of normal person doesn’t contain
blood.
 It may be present due to various pathological and
physiological condition.
 In some cases, very scanty blood may be present
and can’t be detected by physical appearance.
 This test is used to detect trace amount of blood in
stool for which various chemicals are used.

53. VOLUME
− Normal range (600-2000ml)
− Polyuria : more than 2500ml (within 24 hours)
− Oliguria : less than 500ml urine day
− Anuria : complete suppression of urine formation
COLOUR AND ODOR
- light yellow to pale yellow or white clear
- concentration of urochrome pigment.
− Diet, medicines and various chemical disease can affect
the colour
− Urine becomes more ammonia-like due to bacterial
activity.

54. ReactionandpH
− Ranges from 4.5 -8.0, average :6.0( i.e.slightly acidic)
− High protein intake : acidic urine
− High vegetative diets and bacterial infections : alkaline
− In case of UTI urine is acidic in case of infection with E.coli
Specific Gravity
Normal range : 1.003- 1.035 gm/cm^3
 Measurement of density of urine
 high specific gravity: Diabetes mellitus, adrenal abnormalities
or excessive water loss, diarrhoea or kidney inflammation
 low specific gravity: Diabetes insipidus, excessive water intake,
chronic renal failure

55. APPEARANCE
− Normal urine is usually clear
− Cloudy: presence of amorphous phosphate
− Turbid : presence of WBC / epithelial cells and bacteria
− Milky : presence of fat
SEDIMENT FORMATION
In case of WBC, amorphous phosphate epithelial cells,
sediments formation occurs at the bottom of container.
‐ Normal urine is transparent or clear
‐ Cloudy urine may be evidence of phosphates, ureates,
mucus, bacteria, epithelial cells or leukocytes

56. CHEMICAL
 Protein:
- Measured in urine by testing for the presence of albumin
- (Proteinuria): indicator of kidney disease,bladder or
kidney stones, multiple myeloma, haemolytic anaemia
 Glucose:
Uncontrolled diabetes, kidney/hormonal disorders,
liverdisease.
 Ketones:
-indicate that fat is being metabolished instead of
carbohydrate for energy
-raised ketones indicate diabetic condition

57. Urobilinogen
 +ve test: hepatitis / cirrhosis of the liver
 Urobilinogen result is compared with the bilirubin result
 A negative test for bilirubin but positive for urobilinogen
can indicate haemolytic.
 A lower negative test result for urobilinogen in a patient
with positive bilirubin test indicate hepatic obstruction.
Bilirubin
 A waste product created when old RBCs are broken down,
usually removed as component of bile
 A positive test for bilirubin is an early indicator of hepatitis,
liver disease or jaundice

58. Blood
 Urine normally contains a small amount of
haemoglobin.
 A slight increase in haemoglobin can be significant in
terms of potential causes such as a urinary tract
infection, kidney disease, trauma, strenuous exercise.
Nitrite
 Indicator of presence of a range of bacteria that can
cause a urinary tract infection
Leukocytes
 Significant increase in level of leukocyte indicates
inflammation of the kidney/urinary tract or
bladder/kidney infection.

60. MICROSCOPIC
 RBCs: Its no. elevation indicates injury,
inflammation, disease/infection of the urinary
tract(eg: bladder/kidney/urethra)
 WBCs: indicate infection or inflammation in
urinary tract
 Epithelial cells:
-Transitional: indicates an infection in bladder
-Squamosal :indicates an external urethra
-Kidney cell indicates a kidney conduction

63.  Microorganism:
-Trichomonas: responsible for vaginal infection
-Yeast :indicates a vaginalyeast infection
-Bacteria: cause urinary tract infection, kidney
infection
-Casts: indicate kidney disorder
-Crystals: abnormal crystal cuase pain and
damage to the urinary tract such as: cystene,
tyrosine,leucine.

67. Blood test
 Thin smear
 Fixed in methanol
 To examine parasitemia and recognize them and their parasitic
form like : schizont, gametocytes
 Thick smear
 Not fixed in methanol
 RBCs to be hemolysed
 Leukocytes and many malarial parasites present will be the only
detectable elements
 Mainly used to detect infection and to estimate parasitemia

68. Stains used for thick and thin
blood film
 Giemsa’s stain
 Leishman’s stain
 May-grunwald stain
 Jenner’s stain
These stains allows for the detection of
WBCs, RBCs and platelet abnormalities

69.  Thin smear
1. Put a small drop of blood on a clean glass slide and
spread using a spreader , making an angle of 35-40 . A
tongue shaped smear should be made
2. After drying and proper labelling of smear , fix with
methanol for 5-10 minutes
3. Stain with 1:10 diluted Giemsa stain for 45 minutes
4. Wash with tape water , allow to dry and examine
under microscope

70.  Thick smear
1. Place a drop of blood on a clean glass slide
2. Spread in an area a half – inch square or diameter
with the help of a needle or the corner of another
slide
3. After drying , dehaemoglobinize with distilled
water or acetic tartaric acid solution or 2 % acetic
acid solution until the smear appears greyish –
white
4. Drain off the excess dehaemoglobinize agent and
fix with methanol for about 5 minutes (when using
acetic acid tartaric acid solution , the smear should
be treated with slightly alkaline water to remove or
neutralize the excess of acid.

73. Use of Blood Smear

74. Prevention & Control
 In endemic areas, people should be educated
about the dangers of eating raw or under cooked
meat
 Filtration of water is must
 Improve the water supply in affected
communities
 Animal wastes and feces should be disposed in
sanitary way out of reach of water resources
 Wash your hands regularly especially after
handling uncooked food or feces

75. CONTD.
 Keep your fingernails short and scrub under them
with a nail brush.
 In public toilets, don't sit on a bare toilet seat
without protecting it with paper; squat if possible.
 Pinworm eggs and Trichomonas can be present
on toilet seats.
 Trichomonas can also be spread through mud or
water baths, or from sauna benches.
 Avoid walking barefoot, especially in warm, moist
sandy soil.
 Don't use tap water to clean contact lenses - use
sterilized lens preparations.
 Use a shower filter or bath-water filter.

76. Safety rules
-Don’t eat or drink in lab
-Wear coverings like: apron, gloves, proper shoes
-Don’t clean up with hand if spilled
-Mouth pippetting is avoided
-Don’t taste any chemical substances
-Clean work area and hand when work is finished
-If chemicals come in contact with skin clean
immediately and inform lab instructors