This slides deeply explain about the malarial parasite plasmodium

1. By
A.S.ARUL LAWRENCE
Principal, St.Joseph College of Education,
Nanguneri-627108, Tamil Nadu.
E-mail : arullawrence@gmail.com.
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2. Causal Agents:
• Blood parasites of the genus
Plasmodium.
• There are approximately 156 named
species of Plasmodium which infect
various species of vertebrates.
• Four are known to infect humans:
P. falciparum, P. vivax , P. ovale and
P. malariae.
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3. What is a Malarial Parasite?
The malarial parasite, Plasmodium, is a
very small, single-cell blood organism, or
'protozoan'.
 It lives as a parasite in other
organisms, namely man and mosquito. The
parasite is the cause of the tropical disease
Malaria.
The Plasmodium parasite is dependent on
a single species of
mosquito, Anopheles, which is the only
species capable of serving as host for it. 3

4. Male & Female Plasmodium.
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5. Classification
 Phylum : Protozoa
 Sub- Phylum : Sporozoa
 Class : Telosporea
 Sub-Class : Coccidia
 Order : Eucoccida
 Sub-Order : Hamosporidiidea
 Family : Plasmodiidae
 Genus : Plasmodium
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6. Geographic Distribution.
 Worldwide, malaria usually
restricted to tropical and subtropical
areas and altitudes below 1,500 m.
 P. vivax is more common in Central
America and the Indian subcontinent
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9. Infection rate.
 WHO estimates that yearly 300-500
million cases of malaria occur and
more than 1 million people die of
malaria.
 P. vivax and P. falciparum are the most
common.
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10. Mode of
Infection.
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11. Vector & Parasite.
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12. Life cycle.
 A malaria-infected female Anopheles
mosquito inoculates sporozoites into the
human host during a blood meal.
 Sporozoites infect liver cells and mature into
schizonts, which rupture and release
merozoites (exo-erythrocytic schizogony).
 In P. vivax and P. ovale a dormant stage
(hypnozoites) can persist in the liver for
weeks, or even years. The merozoites infect
red blood cells.
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13. Life cycle…
• The ring stage trophozoites mature into
schizonts, which rupture releasing merozoites
(erythrocytic schizogony).
• Some parasites differentiate into sexual
erythrocytic stages (gametocytes).
• The gametocytes are ingested by an Anopheles
mosquito during a blood meal.
• The microgametes penetrate the macrogametes
generating zygotes in the mosquito's stomach.
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14. Life cycle…..
• The zygotes become ookinetes and invade the
midgut wall where they develop into oocysts.
• The oocysts grow, rupture, and release
sporozoites, which make their way to the
mosquito's salivary glands (sporogonic cycle).
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16. Sporozoite Invasion.
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17. Erythrocytic Schizoite.
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18. Amoeboid Stage.
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19. Ring Stage.
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20. Male Gamete.
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21. Female Gamete.
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22. Fertilization.
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23. Mature Oocyst.
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24. Rupturing of Oocyst.
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25. MALARIAL PARASITE’S
DIFFERENT CYCLES
CYCLES OF PARASITE
HUMAN - ASEXUAL MOSQUITO - SEXUAL
(SCHIZOGONY) (SPOROGONY)
EXOERYTHROCYTIC ENDOERYTHROCYTIC
CYCLE CYCLE
(LIVER) (BLOOD)
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26. Sickle cell anaemia and malaria
 A genetic disorder, called sickle cell anaemia, happens
when a person inherits two faulty genes to make the
haemoglobin in their red blood cells which then break
open and cause serious damage due to blood clots.
 Carriers who possess one faulty haemoglobin gene and one
normal gene do not suffer from anaemia but are found to
have some protection against infection by the malaria
parasite.
 In areas where malaria is common, the amount of sickle
cell carriers is higher than in other parts of the world.
 In an unusual example of Darwin's principle of survival of
the fittest, carriers of the genetic disorder are actually
more likely to survive than people with two unaffected
genes for haemoglobin.
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27. Plasmodiu
Plasmodiu
Plasmodium m Plasmodium
Species m
vivax malaria falciparum
ovale
e
Pre-erythrocytic cycle (days)1 8 9 13 5.5-6
Pre-patent period (days)2 11-13 10-14 15-16 9-10
13 (12-17) or up 17 (16-18) 28 (18-40)
Incubation period (days)3 to 6-12 or or 12 (9-14)
months longer longer
Present in
some
Exo-erythrocytic cycle (secondary)4 Present Present Absent
strains
?
Approximate number of merozoites
Over 10,000 15,000 2000 40,000
per tissue schizont
Erythrocytic cycle (hours)5 48 49-50 72 48
Parasitemia (per l (mm3) Average 20,000 9000 6000 20,000-500,000
Maximum 50,000 30,000 20,000 2,000,000
Severe in non-
Primary attack severity Mild to severe Mild Mild
immunes
Febrile paroxysm (hours)6 8-12 8-12 8-10 16-36 or longer
Relapses ++ ++ +++ -
Period of recurrence7 Long Long Very long Short
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Duration of infection (years) 1.5-3 1.5-3 3-50 1-2

28. 1. Vivax malaria
2. Tertian malaria
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29. Symptoms:
 The most frequent symptoms include
fever and chills, which can be
accompanied by headache, myalgias,
arthralgias, weakness, vomiting, and
diarrhea.
 Other clinical features include
splenomegaly, anemia, thrombocytopenia,
hypoglycemia, pulmonary or renal
dysfunction, and neurological changes.
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30. Laboratory Diagnosis:
 Microscopy Microscopic identification is the
method most frequently used to demonstrate an
active infection.
 Comparison of Plasmodium species
 Molecular diagnosis techniques can complement
microscopy, especially in species identification.
 Antibody Detection can detect past (not
necessarily active) infections.
 Immunologic/Biochemical detection of malaria
parasite products are available and under
evaluation 30

31. Treatment:
• Treatment varies according to the
infecting species, the geographic
area where the infection was
acquired, and the severity of the
disease.
• A complete guide for treatment of
malaria can be found in The Medical
Letter (Drugs for Parasitic
Infections), as well as on the Division
of Parasitic Diseases Web site.
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32. Prevention.
• Personal protection against
mosquito bites is the first line of
defence against malaria.
• In addition, travellers should
take chemoprophylaxis where
appropriate
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