#P.faliciparum

1. COLLEGE OF HEALTH SCIENCES AND MEDICINE
SCHOOL OF MEDICAL LABORATORY SCIENCE
DEPARTMENT OF MEDICAL LABORATORY SCIENCE
ASSESSMENT TYPES: SEMINAR PRESENTATION FOR 4TH YEAR MLS
STUDENTS
 SEMINAR PRESENTATION TITTLE:PLASMODIUM
FALCIPARUM

2. GROUP MEMBERS
NAME ID NO
1.Kuba Girma ........................................RU1862/12
2.Melkamu Abebe.......................................RU1971/12
3. Melesa Solomon......................................RU1963/12
4. Mihiret Abebaw......................................RU2012/12
5. Abdukarim Sultan....................................RU1057/12
6. Hailiye Woldu.........................................RU1718/12
7. Dejen Zewudu........................................RU1446/12
8.Belaney Yeshambel..................................RU1291/12
9.Ararsa Belama.........................................RU1227/12
10.Gedfew Betsaha ....................................RU1645/12
11. Misgana Abay........................................RU2024/12
12.Almaz Desta..........................................RU 1191/12

3. Plasmodium falciparum (P. falciparum)
Introduction
 P. falciparum: most prevalent in the hotter and
more humid regions of the world.
 This is the most highly pathogenic of all the plasmodia and hence the name
malignant tertian or pernicious malaria for its infection. The disease has a high
rate of complications and unless treated is often fatal.
This is the species of the greatest public health importance due to its increasing
resistance to antimalarial drugs and its spread to new areas.
Malaria is the most important parasitic disease of mankind .an acute and chronic
infection caused by protozoans of the genus Plasmodium.

4. Sign and symptoms
paroxysms comprises of
three successive stage: cold
stage, hot stage and sweating
stage
1. the cold stage
• feeling of intense cold
• vigorous shivering, rigor
• lasts 15-60 min

5. Cont ....
2.The hot stage
• intense heat
•dry burning skin
•throbbing headache
•lasts 2-6 hours

6. Cont ....
3.sweating stage
•profuse sweating
•declining temperature
•exhausted, weak 
sleep
•lasts 2-4 hours

7. Morphological Stages of p.falciparum
• Sporozoite: develops in the mosquito salivary gland
• Hepatic schizont actively dividing, multinucleated, parasite form in
hepatocytes
• Trophozoite: metabolically active form living within the RBC
• Sometimes called the ring form
• Erythrocytic schizont: multinucleated stage in a RBC resulting from asexual
multiplication of trophozoite
• Each schizont contains a species determined number of merozoites

8. Morphological .....................
• Merozoite: infective schizont components that break out of
hepatocyte or RBC
• Gametocyte: morphologically distinctive sexual (male or female) form
which develops from some trophozoites in RBCs

9. Transmission and life cycle of p.falciparum
Principal mode of Transmission
1.Bites of female anopheles mosquito
60 species of mosquito
Sucks the gametocytes during blood meal
Bites between 5 PM and 7 AM, with maximum intensity at
midnight.

10. transm......................
2. Blood transfusion (Transfusion malaria)
 This is fairly common in endemic areas
 Following an attack of malaria, the donor may remain infective
for:
 1-3 years in P. falciparum,
 3-4 years in P. vivax, and
 15-50 years in P. malariae

11. transm...............
3. Mother to the growing fetus (congenital malaria)
• occurs in 5 % of new borne whose mothers are infected
• relatively rare although placenta is heavily infected
• Congenital malaria is more common in first pregnancy, among
non - immune populations.
4. Needle stick injury:
• Accidental transmission can occur among drug addicts who share
syringes and needles.

12. Life cycle malaria
• Require two host
• Man
• intermediate host
• Asexual reproduction
• Liver cell
• RBC
• Mosquitoes
• Definitive host
• Sexual reproduction

13. life cycle....................
IN THE MOSQUITO
• During a blood meal on man, female Anopheles mosquito picks up
mature gametocytes
• In the mosquito's mid gut, a micro gamete(male) penetrates a macro
gamete(female) and form a zygote
• The zygotes inturn become motile and elongated form called
ookinetes

14. lif................
• invade the midgut wall of the mosquito where they develop into
oocysts
• The oocysts expanding by asexual multiplication, grow, rupture, and
release motile sporozoites , which make their way to the mosquito's
salivary glands
• Inoculation of the sporozoites into a new human host perpetuates
the malaria life cycle

15. life cycle.........................
In man
 During a blood meal, malaria-infected female Anopheles mosquito inoculates
sporozoites and salivary fluid
 The sporozoites remains in the circulating blood for only 30
minutes
 The kupfer cells of the liver kill and clear many sporozoites from
blood stream

16. life............................
 Development to erythrocytic schizont in P. falciparum takes place in the
capillaries of deep tissue .
 The mature schizont rapture from red blood cells
 releasing merozoites , malaria pigment and toxins in to plasma
 Merozoites ,which are not destroyed by host immune system infect
new red blood cells, initiates further cycle of erythrocytic schizogony
with more red blood cells begin destroyed.

17. life.....................

18. Factors for Malignance of P.falciparum
• Rapid multiplication
• Infected red blood cells become "stick"
• Infects all age group of red blood cells
• A single red blood cell can be infected by more than one parasites
• Erythrocytic schizogonic reproduction takes place in the deep
capillaries of organs such as brain, lung, heart, spleen, bone-marrow,
placenta, intestine, etc.

19. Predisposing factors for complications of P.
falciparum malaria
(1.) Extremes of age.
(2.) Pregnancy, especially in primigravidae and in
2nd half of pregnancy.
(3.) Immunosuppressed - patients on steroids, anti-
cancer drugs, immunosuppressant drugs
(4.) Splenectomy.
(5.) Lack of previous exposure to malaria (non-immune) or lapsed
immunity
(6.) Pre-existing organ failure

20. cont...................
• Pathogenecity of P. falciparum
1.Higher Parasitemia in Falciparum Malaria
• all erythrocytes invaded
• up to 36 merozoites
• Pv/Po = reticulocytes
• Pm = senescent RBC
P.falciparum.
-Up to 30-40% of RBC
- sever if > 5% RBC are infected.
P.vivax & P.ovale rarely exceeds 2%
P.malariae. Usually < 1%

21. lab........................
laboratory diagnosis of malaria

22. Microscopy examination
• Microscopic examination of blood film.
 Established method for confirmation of malaria- the gold standard.
 Requirements:
 Carefully collected blood specimen/sample
 Well prepared blood films
 Well stained smears( Romanowsky stains)
 Careful examination of the smears

23. micr......................

24. Collection of Blood Specimen
I. Collect sufficient quantity of blood
1. Capillary blood from finger prick , toes, or ear
lobes –best
2. Venous blood.(EDTA anticoagulant)
3. In obstetric practice, cord blood and placental impression smears
can be used
II. Time of collection
 When the patients feel febrile
 Before anti-malaria drugs are given to the patient.

25. I.Preparation of Thick Films
I. slides must be clean, free
from dirt, grease and
fingerprints
II. Mix the blood
III. Using an applicator stick,
apply 4 drops of blood on to
a microscope slide
IV. Spread the blood without
excessive stirring to form a
smear approximately a cm2,
through which newspaper
print can be red.
V. This should be approximately
5 red blood cells thick.

26. II. Preparation of Thin Films
1. The microscope slides must be
clean as for thick films otherwise
the blood will not adhere and the
smear will be irregular.
2. Apply 1 drop of blood to the end
of the slide, pace another slide at
an angle of 45o and bring it
towards the drop of blood.
3. As soon as touches it, the blood
will disperse along the width of
the slide.

27. thin...............
5.Before it reaches the edges, pull the drop along the length of the slide.
6. The correct amount of blood in the drop the film will form a good tail
before the end of the slide. The film here should be 1 RBC thick. Make 2
slides for each test.
7. Air dry, Label slides

28. cont.....................
Staining With Giemsa
Immediately before use dilute the Giemsa as required
3% for 30 min
10% for 10 min
 Thin films must be fixed in absolute methanol for at least 30
seconds(1-2min)
Stain
Wash
Drain & dry vertically/ at an angle.

29. cont.............
Microscopic examination of blood films
 Focus on the film with the X10 objective.
Examining the film first with 40x objective to select a well stained area
Apply a drop of immersion oil on the slide and switch to the oil-
immersion objective(100).
Examine at least 100 fields(100Xobjective)
*P.malariae exam approximately 200 fields

30. cont...........
Microscopic features of three blood stages
trophozoites, schizonts, gametocytes
All these three stages have:
Red nuclear chromatin, blue cytoplasm and pigment (except young troph)
What are the key features of :
trophozoites
single (Sometimes double) chromatin bead
Cytoplasm as a ring uniform or fragmented mass
Pigment absent from young (ring) form

31. Cont.....................
 Schizonts
 2-32 chromatin beads
 Cytoplasm-typically irregular, amoeboid
 Pigment in early and late form
 Gametocyte?
 Single chromatin bead (diffuse in male)
 Round or crescent shaped
 Solid cytoplasm
 Pigment in early and late stage

32. cont..................
P.falciparem
Young Trophozoite (Ring forms)
 Stage frequently found in blood
film
 Size: Very delicate, 0.15-0.5
diameters of RBCs which is
unaltered in size.
 Shape: small fine pale blue ring
 Chromatin: 1 or 2 small red dots.
 Often with double chromatin dot
 May lie on red cell membrane
(accole forms)
 Pigment: absent

33. cont..................
Mature Trophozoite
• Stage rarely seen in peripheral blood
• RBC unaltered in size, sometimes
stippled, pale
• Size: small
• Shape: compact thin blue ring ,
comma or exclamation mark
• Chromatin: 1 or 2 red dots
• Pigment: black or dense brown mass
• Stippling Maurer's cleft

34. cont..................
Gametocytes
 RBC is distorted.
 Fairly frequently found
 Size: larger than red cell
 Shape: crescent or banana
 Male:- Bluntly round ends
 Female:-Rounded/pointed ends
 Cytoplasm: Reddish blue(Male)/Dark
blue(female)
 Chromatin:
 Male:-fine granules scattered
 Female:-compact masses near
center.

35. Reporting blood films for malaria parasites
REPORTING THICK BLOOD FILMS
• plus sign scheme :
Parasites
1 – 10 per 100 high power fields ………………… +
11 -100 per 100 high power field…………………++
1 – 10 in every high power field…………………+++
More than 10 in every high power field ………. ++++
• Example: P. falciparum trophozoites +++, gametocytes +, with malaria
pigment in white cells

36. reporting....................
 If no parasites are found after examining 100 fields (or if indicated 200
fields), report the film as:
Malaria thick film: NPF (No parasites found)

37. REPORTING THIN BLOOD FILMS
COUNTING PARASITE NUMBERS
The following two methods are commonly used:
1. Estimating parasite numbers/µl of blood from the thick film.
count a total of at least 500 red cells making a note of the number
that contain parasites excluding gametocytes and at the end report in
percentage
Note:-A serious P.falciparum infection is indicated
 when 5% of more of the red cells are infected.
 E.g. When 10-20% of the cells are parasitized the prognosis is serious,
with 20-30% it is grave and over 30% it is exceptionally grave.

38. Treatment
Antimalarial drugs like
Chloroquine
 Widespread resistance has now rendered it virtually useless against P. falciparum
Artemisinin - active against all Plasmodium species
Pyrimethamine in combination with a sulfonamide
 Effective against all four human malarias
And other can be used

39. Prevention and Control
1.Avoid mosquito bites by
 Using impregnated bed nets
 Wearing protective clothes
 Using mosquito repellents
 screens, house spraying
2. Destroy adult mosquitoes by
 Indoor residual regular
effective spraying
3.Preventing breeding of mosquitoes by
 environmental modification
 Spraying breeding places with
effective larvicides
 Biological control
4. Treatment
 Active infection
 Chemoprophylaxis
5) Health education
6) Blood screening for malaria

40. summary
• Development to erythrocytic schizont in P. falciparum takes place in the
capillaries of deep tissue.
• P. falciparum: most prevalent in the hotter and more humid regions of the
world.
 if no parasites are found after examining 100 fields (or if indicated 200
fields), report the film as:
Malaria thick film: NPF (No parasites found)

41. Reference
• medical parasitology Textbook , 6 th edition.
• parasitology Pdf.

42. Thank you