Maleria causes treatment, control and its life cycle

1. By
Dr. Priti D.Diwan
Assistant Professor
Department of Zoology
J.D.Patil Sangludkar Mahavidyalay Daryapur.
Plasmodium vivax
( MALARIALPARASITE)

2.  The most interesting sporozoan genus is plasmodium
 Because of their malaria causing abilities , these species commonly
referred as malarial parasites
 All resides in the RBC
 Mosquitoes are the vectors
The Malarial parasite

3.  4 species are known to cause different types of malaria
 P.vivax, P.ovale, P.malariae and P.falciparium
 Geographically distributed in tropical and temperate countries
 P
. vivax is most commonly distributed and prevails in the
temperate regions of the world.

4. Life Cycle of P. vivax
• P. Vivax is the most common of the human infecting malaria fever
parasites.
• Causes benign tertian or vivax malaria, characterized by a 48 h
cycle b/w first fever and subsequent chills and fever.
• Hosts: diagenetic
a. Man:
asexual cycle in two phases
First in liver – liver schizogony
Second in RBC – erythrocytic schizogony and forms gametes
b. Mosquito:
Sexual cycle is completed in female anopheles
It involves gametogony and sporogony

5. Asexual cycle of P.vivax in man
[1]. Infection
• Anopheles bite resulting in the inoculation of thousands of sporozoites
along with saliva into the persons body (victim)
[2]. Sporozoites
• Infective form of parasite
• Small, spindle shaped measuring about 11-12 µ in length and 0.5-1µ
in width

6. [3]. Liver Schizogony
• After 30m of infection, sporozoites invades hepatic tissues andmultiply
by schizogony in two phases (pre and exo-erythrocytic)
a). Pre-erythrocytic phase
• Sporozoite becomes cryptozoite in hepatic cells and becomes spherical
and non-pigmented schizont.
• Undergo multiple fission (schizogony) and forms numerosuninucleate
cryptomerozoites
• At the end of phase, hepatic cell bursts and cryptomerozoites are
liberated.
b). Exo-erythrocytic phase
• Cryptomerozoites enter new liver cells and becomesmetacryptozoites
• Undergo similar schizogony and produces metacryptomerozoites.

7. [4]. Erythrocytic schizogony
• Micro metacryptomerozoites invades RBC and starts erythrocytic
schizogony and includes following stages:
a). Tropozoite stage
• Inside RBC, micro metacryptomerozoites becomes rounded and
modified into trophozoite.
b). Signet ring stage
• Trophozoite grows, develops vacuole and clinically referred as
signet ring stage.
c). Amoeboid stage
• Meanwhile signet stage develops into active amoeboid trophozoite
• At this stage, samle red eosinophilic granules appear in the
cytoplasm –schuffners granules
d). Schizont
• Amoeboid trophozoite after feeding becomes rounded, grows in
size and becomes schizont
• It undergoes schizogony and forms merozoites
• One erythrocytic cycle takes 48h

8. [5]. Post-erythrocytic schizogony
• Sometimes merozoites reach the liver and undergoes schizogonic
development in the liver cells –post-erythrocytic schizogony.
[6]. Formation of gametes
• Merozoites increases in size to become rounded gametocytes.
• Male – microgametocyte and female- magagametocyte
• Gametocytes donot devide but remain as intracellularparasite
until they either die or ingested by vector

10. Sexual cycle of P.vivax in man
[1]. Ingestion by mosquito
• Female anopheles gets the infection by sucking the blood of infected
person
• RBC are digested and gametocytes are liberated and lodged into the
cavity of the gut.
[2]. Gametogony
• Development of gametes (Haploids) from gametocyte – gametogony/
gametogenesis.
• Gamtes are of two types
a). Microgametes
• Male or microgamete undergoes exflagellation in the midgut of mosquito
• Each nucleus divides by mitosis and produce 6-8 haploid daughterand
assemble at periphery
• Cytoplasm outgrows into long thin flagella like projection and later these
projections break away as mature male gamete
b). Megagametes
• Female megagametocyte undergo some reorganisationa nd becomes a
female gamete, which is ready for fertilization.

11. [3]. Fertilization
• Megagamete gives out a cytoplasmic projection – fertilization cone.
• Microgamete attached to this cone and transfer its nucleusto
megagamete
• Fertilization or syngamy takes place
• Diploid zygote forms
[4]. Ookinete
• After sometime zygote becomes active and shows gliding moment andis
k/as ookinete
• It measures about 15-22 micron in length and 3 micron in width.
•It attaches itself to peritrophic membrane of gut.
[5]. Encystment
• Ookinete penetrates through walls of midgut, becomes sphericaland
begins enyst.
• The encysted zygote – oocyst / sporont

12. [6]. Sporogony
• Oocyst enters into a phase of asexual multiplication-sporogony
• Firstly divides by meosis and then by mitosis and formsenormous
haploid nuclei surrounded by cytoplasmic masses
• The daughter nuclei arrange themselves along the margin of
cytoplasmic masses and later forms slender finger likeprocesses
having single nuclei in each
• In this way about 10,000 minute slender and sickle bodiesare
formed-sporozoites .
• When sporozoite matures oocyst ruptures and liberated into
haeomocoel later penetrates into salivaryglands
• Whole sexual cycle completes into 0-12 days
• Now mosquito becomes infective

13. Pathogenesis of malarial parasite
Symptoms of malaria first appear several
days after the infection of the parasite.
This time – incubation period
Each attack of fever shows threestages:
1. Cold Stage
• At the onset of malaria patent suffers
from severe shaking chill.
• Cold stage lasts for 20 min
2. Hot stage
• As the chill subsides, the body temp rises
as high as 106°F. and lasts for 1-4 h.
3. Sweating stage
• As the temp lowers down, patent sweats
profusely.
• Fever comes down and temperature
becomes normal

14.  Malaria fever occurs when schizont in RBC bursts and set free
their merozoites and malarial pigment haemozoin in the plasma.
 Anemia is inevitable due to:
• Destruction of RBC
• Infected RBC become more fragile and rupture easily
• Parasite produce haemolysin- brings haemolysis
• In chronic case- spleen becomes enlarged
Control of Malaria
Control Measures falls into three categories:
1. Elimination or destruction of vector
2. Prophylaxis (prevention of infection)
3. Treatment of infected patents

15. [A]. Destruction of anopheles
Most effective and surest way of controlling malaria and can be
done through
• Destruction of adult mosquitoes: method used are killing of
hands, traps, fumigation, spraying and sterilization.
• Elimination of breeding places: swampy, marshy and water
logging areas are cleared out, bushes and shrubs are cleared
off etc.
• Destruction of larvae and pupae of mosquito through proper
drainage (Flowing water), oil screens, chemical larvicidesand
biological methods.
[B]. Prevention of infection
• Through the use of insect repellent, nets, gloves and by
screening bedroom windows.
[C]. Treatment
• Chlorquine and quinine: anti-erythrocytic stage drugs.
• Primaquine and pyrimethamine: anti-exoerythrocytic stage
drugs.