Life bcycle of Plasmodium vivax

1. GAURAV PAL (12BSZBC021)
AND
TANMAY SRIVASTAVA (12BSLSCFS015)

2. PLASMODIUM
(MALARIAL
PARASITE)

3. CLASSIFICATION
Phylum- Protozoa
Sub Phylum- Plasmodroma
Class- Sporozoa
Order- Haemosporidia
Genus- Plasmodium

4. Introduction
Members of class Sporozoa are parasite so locomotory organs
are absent in Plasmodium
Members of order Haemosporidia show digenetic life cycle i.e. Plasmodium
completes its life cycle in two hosts.
Primary host- Human being; where it completes it asexual life cycle.
Secondary host- Female Anopheles; where it completes mainly
its sexual cycle.
Reservoir host- Monkey.

5. CONT….
Eradication of Plasmodium is not easy due to its
several host.
Another reason is that vaccine can’t be formed because,
Plasmodium don’t induce human body to form antibodies
and hence no immunity against Plasmodium can develop.
Number of chromosome in Plasmodium= 10

6. Different species of Plasmodium
About 60 species are known but only
4 are pathogenic.
1)-Plasmodium
vivax
Most common species.

7. 2)-Plasmodium falciparum
Most lethal
species.

8. 3)-Plasmodium malariae
Less harmful
species.

9. 4)-Plasmodium ovale
Absent in India and
present in Philippines
and Africa.

10. Life cycle of
Plasmodium

12. Life cycle of Plasmodium in
Humans
• Liver
• RBC
There are two sites for
activity of Plasmodium in
human-
All the activities that occur in liver are known
as Exo erythrocytic cycle.
Whereas activities in RBC are termed as
Erythrocytic cycle.

13. Infective stage of Plasmodium
for human is sporozoite.
These sporozoite are present
in the salivary gland of female
Anopheles.
The amount of sporozoite are
about 2,00,000.

14. Female Anopheles

16. Structure of sporozoite
It is spindle or some times sickle shaped.
Body is covered with pellicle which is made up of 11-15 microtubules.
Sporozoite contains an aperture at the apex
called Micropyle.
A structure that covers micropyle is known as
Apical cap.
This cap is made up of 3 concentric
microtubules.

17. A pair of secretory organelles are
related to micropyle.
It contains lytic enzymes which helps
sporozoite to penetrate human liver
cells.
A big oral shaped nucleus is present
in middle of sporozoite.
Just beneath it Mitochondria is
present.

18. An anticoagulent
(Anophilin) is
secreted when female
Anopheles bites.
It do not
allow
blood to
clot so
that
Anophel
es can
suck
blood
easily. With the saliva,
numerous of
sporozoites
enters in human
blood.
Within 30
minutes all
of the
sporozoite
s
approache
s the liver
and no
sporozoite
is visible in
the blood.

19. Pre erythrocytic cycle
First life cycle of Plasmodium in liver.
Plasmodium starts its life cycle from
liver as:-
• To prevent itself from phagocytic action of
WBC.
• It uses glycogen as food and liver is rich in
glycogen.
• To multiply in number.

20. Sporozoite enter in
the liver cell and
become spherical by
phagocyting the
cytoplasm.
Now these are
termed as
cryptozoites.
This results in the
formation of 1000-
1500 small
structures called as
cryptomerozoites.
These undergo
multiple division
called schizogony.

21. At this stage cryptozoites is called
schizont.
Finally cell memberane of liver cell and
schizont burts and cryptomerozoites
are now free in blood sinusoides of
liver.
A few of these cryptomerozoites infect
RBC and start the erythrocytic cycle.

22. Schizont stage

23. Rest of the cryptomerozoites go back in
liver cells and start the post
exoerythrocytic cycle.
Time taken to complete pre erythrocytic
cycle is called Pre patent period.
In this period Plasmodium is
not visible in blood.

25. Post exoerythrocytic cycle
In this cycle,
cryptomerozoites
infect the liver cells.
They phagocyte the cytoplasm
and become big and spherical.
Now these are
known as
metacryptozoite or
phanerzoite.

26. Two types of
metacryptozoites are
formed-
Micro
metacryptozoites
(MICRO MCZ)
Macro
metacryptozoites
(MACRO MCZ) MICRO MCZ are further
converted into 100-1000
merozoites by the
process of schizogony.
The product is called
Micro meta
cryptomerozoite
(Micro MCM).

27. Similarly Macro MCZ
produces 64 merozoites
which are called Macro
meta crypto merozoite
(Macro MCM).
Micro MCM infect only
RBC whereas Macro
MCM infect liver cells.
This cycle goes on
repeating again and
again which causes
destruction of liver cells.
In case of an excessive
malaria, liver may
damage and jaundice
like symptoms may
appear.

28. Erythrocytic cycle
This cycle is
also known
as Golgi
cycle.
This cycle
starts at first by
Cryptomerozoit
es and further
carry on by
micro meta
cryptomerozoit
es.
Cryptomerozoites
infects RBC.
They phagocyte
haemoglobin of
RBC and become
big and spherical.
Now they are
called as
trophozoite
s.

30. Later on a
big
central
vacuole is
formed in
the
cytoplasm
of
trophozoit
es.
This
makes
it
appea
r like a
ring.
So this
stage is
called
Signet
ring
stage.
After a
while
vacuole
is lost
and
trophoz
oites
become
irregular
in
shape.
At this
stage
Plasmo
dium
looks
like
Amoeb
a so
this is
called
as
Amoeb
oid
stage.

31. Signet ring stage

32. This is
active
and
feeding
stage of
Plasmodi
um.
It
phagocyte
s
haemoglob
in quickly
and grows
up and
occupies
whole of
the RBC
approx.
Particularly
, at this
stage
reddish
brown
colored
granules
are seen in
the
cytoplasm.
These are
called
haemozoin
granules.
It is the non
digested part
of the
haemoglobin.

33. Haemozoin granules in food
vacoule

34. At the same
time bright
yellow
colored
granules
appear in the
cytoplasm of
RBC.
These are
called
Schuffner’s
dots which
are probably
waste
products of
Plasmodium.
These dots
are used in
diagnosis of
malaria as
they are the
most clear
structures
that appear
in blood.

35. Schuffner’s dots

36. There are two species of Plasmodium
that do not form Schuffner’s dots.
1)- P. malariae – They form red
colored Zeiman’s dots.
2)- P. falciparum- They form green
colored Maurer’s dots.
• Both of these are also helpful in diagnosis of
malaria.

38. Rosette stage

39. Brust RBC is called ghost RBC.
Spleen uptake this ghost RBC from the blood
and destroy it by special type of phagocytic
cells called as macrophages.
These cells secrete an enzyme Lysolecithin
which destroy ghost RBC.
In case of excessive malarial infection, spleen
becomes large and swollen this disease is
called Megaly of spleen or spleen index.

40. Spleen index Macrophage
cell

41. It is due to
increase in
number of
macrophages
and
lysolecithin
causes
swelling.
Excessive
malarial infection
may also lead to
Haemolytic
anaemia
because more
lysolecithin
secretion occurs
which reaches to
blood and
destructs the
healthy RBC’s.
So decrease in
number of
healthy RBC’s
causes
anaemia.

42. The time laps between infection
of Plasmodium and first attack
of malaria is called incubation
period.
Plasmodium shows biological
clock system because
Erythrocytic cycle is completed
exactly in 48 hours in case of P.
vivax, P. falciparum , P. ovale
while 72 hours in case of P.
malariae .

43. Post Erythrocytic Cycle
Sometimes merozoites formed by erythrocytic cycle
escapes from blood and enters the liver cells.
These merozoites remain inactive in liver.
After a long time, they become active and multiply in
number.
This causes malaria again.
So after a long time, malaria is repeated again, this is called
Relapse of malaria.

44. Post erythrocytic cycle is not found in P. falciparum.
So relapse malaria do not occur.
Longest relapse of malaria is
found in P.malariae which may
last up to 3 years.

45. Gametocyte stage
When many erythrocytic cycles completed then
merozoites enter the RBC and form a new stage
called as Gametocyte or Gamonts or Resistant
Trophozoite schizont.
Gametocyte is the last stage in human.
Further development occurs in female Anopheles.

47. This is because high
temperature in human is
unfavourable for
gametocyte formation.
There is biological clock
system in Plasmodium i.e.
it forms gametes when
there is more probability
of attack of female
Anopheles.
So gametes are formed
in night, from late
evening up to midnight.

48. Gametocytes
which reach in
female Anopheles
are developed and
rest which are left
in blood are
destroyed in the
morning.
Two types of
gametocytes are
formed-
• Micro gametocyte
• Macro gametocyte
These are
formed in the
ratio of 1:2
respectively.

50. LIFE CYCLE OF
Plasmodium in
female Anopheles

52. There are two types of cycles :-
1)- Gametogony ( sexual cycle )
2)- Sporogony ( asexual cycle )
Gametocyte is the infective stage of
Plasmodium for female Anopheles.
When it sucks blood, many stages
reach in its crop but only gametocyte
stage remains, rest of all are digested.

53. Microgametocytes
undergo the process
of spermatogenesis
in which its nucleus is
divided into 4 haploid
nuclei by meiotic
division.
Gametogenesis
Further, mitosis occurs
and these are
converted into 8 nuclei.
All nuclei are arranged
on periphery.
At the site of every
nucleus, plasmalemma
projects outwards and
8 spindle shaped
projections are formed.

55. Every projection
contains a nucleus
and few cytoplasm.
These projections
are called sperms.
Every sperms
detaches it self from
microgametocytes
by constricting at its
base.
So 8 sperms are
formed by a single
microgametocytes.

56. Exflagellation

57. Macro
gametocytes
forms ovum
by the
process of
oogenesis.
Meiosis
occurs
resulting in
the formation
of 1 ovum
and 3 polar
bodies.
Polar bodies
are
destroyed
further.
A projection
appears on
ovum which
is called
reception
cone.
This is the
penetration
site of sperm
at the time of
fertilization.

58. Zygote is formed as a result of fertilization.
Whole of this process upto zygote formation occurs in
lumen of crop.
Zygote can form in any type of mosquito e.g
Anopheles, Culex, & Aedes etc , but further
development of zygote is possible in female Anopheles.
This is the host specialization of Plasmodium. (as
female Anopheles provides royal jelly.)

59. Development of zygote
Proposed
by Grassi.
According to
him all zygotes
are converted
into long worm
like structures
called ookinete
or vermicule.
With the help of gliding
and wriggling movement
these ookinete enter the
crop wall and are placed
beneath the outermost
layer called peritonium
of the crop wall.

60. A thin and elastic coat is secreted around these
zygotes by both zygote and cells of crop wall.
This stage is called oocyst.
At this stage 50-100 small projections of oocyst
are found on the crop wall.

62. Sporogony
Oocyst takes
nutrition from
the crop wall
and develop into
5-6 times bigger
structure called
sporont.
Many small
vacuoles are
now formed in
the cytoplasm of
sporont.
Nucleus of
sporont is
converted by
free nuclear
divisions into
approximately
10,000 nuclei.
All these nuclei
are arranged on
periphery of
vacuoles.

63. Later on
cytoplasm is
divided and
converted into
10,000 parts
around every
nucleus.
As a result
10,000
sporozoites are
formed.
This sporont is
called as
sporocyst.
Outer most
layer of crop
and wall of
sporont burst
and these
sporozoites are
now free in
haemoceal of
mosquito.

64. Haemocoel is a blood filled cavity.
The blood is colorless and is called haemolymph.
All sporozoites are stored in salivary glands.
About 2 lacks sporozoites are stored in salivary
glands of mosquito which further infect to human
through saliva.

65. Invasive stages
Merozoite
• erythrocytes
Sporozoite
• salivary glands
• hepatocytes
Ookinete
• epithelium

66. Special points about P. falciparum
Malaria caused by P. falciparum called lethal
malaria is the most dangerous malaria because
infected RBC adhere and form thrombus which
may interfere in blood circulation.
Carotid artery is feeding artery of brain so
when this artery is blocked by thrombus
then brain may suffer from less blood
circulation which is unfavourable for it.
Longer duration of this
condition may cause death.

67. When
thrombus is
formed in
coronary
arteries,
which gives
nutrition to
heart, heart
attack may
occur.
Loss of
Haemoglobin
through urine(
Haematuria )
occur in
which color of
urine
changes from
yellow to
black.
Hence, it is
also called as
Black water
fever.
Double signet
ring and
crescent
gametocyte
are
characterstics
of P.
falciparum.

68. Types of malaria
Three types of malaria are recognized on the basis of periodicity of paroxysms
(recurrent attacks of fever)-
1.Tertain malaria or Common ague
Recurrence of fever is after every 48 hours i.e. every
third day.
Caused by P.vivax, P.falciparum, P.ovale.

69. 2. Quartan malaria-
Paroxysms occur at intervals of about 72 hours (every
4th day)
Caused by P.malariae.
3. Quotodian malaria-
Paroxysms are irregular and almost daily.
May be due to multiple or mixed infections by more than
species of Plasmodium.

70. 4. Relapse malaria-
Exoerythrocytic cycles continue uninterrupted
in P.vivax, P.ovale and P.malariae even after
the disease is completely cured.
Merozoites of these cycles can anytime
attack RBCs and cause a relapse of malaria.

71. History of malaria
Mc. Culloh - termed malaria.
Lancisi – suspected that there is any relation
between mosquito and malaria.
Charles Laveran- discovered Plasmodium in
human RBCs and revealed that malaria is
caused by Plasmodium.

73. Sir Ronald Ross- proved the relation
between mosquito and malaria.
About 25000 mosquitoes were dissected by Sir
Ronald Ross in his life.
Female Anopheles is the carrier of Plasmodium.
Awarded by Noble Prize on 29th Aug. 1902.
This day is celebrated as malaria day.

74. Grassi- studied the life cycle of
Plasmodium in female Anopheles.

75. Symptoms of malaria
Due to toxic
effects of
Haemozoin
granules on
body,
symptoms of
malaria
appear.
Initial symptoms of
malaria include,
• Nausea
• Constipation
• Body pain
• Dyspnea
• Weakness in body.

77. After 2 or 3 Erythrocytic cycles Haemozoin
granules increase in number and actual
symptoms of malaria now begins to appear.
This is called Paroxysm of malaria.
• Rigor stage:- alternate contraction and
relaxation in muscles causes shivering and
cold sensations.
• Febrile stage:- after some time shivering
stops and body temperature rises due to
contraction of muscles.
It has 3
stages:-

78. Rise in temperature is beneficial for
patients because internal high
temperature is unfavourable for parasite
Plasmodium. Temperature :- 104- 105 F
*Difervescent stage:- after rise in
temperature excessive sweating
occures and body temperature
decreases.
• Now patient feels himselfs healthy.
• But at this time Erythrocytic cycle
starts again and fever is repeated at a
constant interval of time.

79. Prevention and
Control

80. Control of malaria
Two methods-
• Direct – by killing
Plasmodium.
• Indirect- by killing
mosquitoes.

81. Direct method-
Plasmodium is
destroyed by
chemotherapy.
Old medicines
like Quinine,
destroys only
that stages of
Plasmodium
which are
present in
blood.
Mapacrime
destroys
merozoites
present in
blood.
Paludrine &
Sulphadoxine
destroys all the
stages either in
blood or liver
but are not
generally used
because the
cause harm to
liver cells.
The most
effective
medicine for
malaria is
Deraprim
which
destroys
gametocytes.

83. Indirect
method:-
Following
procedures
are used to
kill
mosquitoes:-
• Insecticides like
DDT (it is now
banned),
Gamaxene,
Melathion etc are
sprayed.
• Biological control:-
more suitable
procedure
- in this larvivorous
fishes are used
which eat larvae of
mosquitoes.

84. THANK YOU