The document discusses various aspects of malaria, including: - Malaria is caused by Plasmodium parasites transmitted via mosquito bites. Four species cause human malaria. - The parasite's life cycle involves stages in the human liver and blood, and the mosquito. - Laboratory tests to diagnose malaria include examining blood smears under a microscope, rapid diagnostic tests, PCR tests, and antibody tests. These help identify the species and guide treatment. Susceptibility testing identifies drug-resistant strains.

1. MALARIA
PRESENTED BY :
P.VIGNESWARI
NIRMALA COLLEGE OF PHARMACY

2. INTRODUCTION
 Malaria is a life-threatening disease. Its typically
transmitted through the bite of an infected Anopheles
mosquito. Infected mosquitoes carry the Plasmodium
parasite. When this mosquito bites you, the parasite is
released into your blood stream.
 Systemic position
Phylum : Protozoa
Subphylum : Apicomplexa ( sporozoa)
Class : Telosporea
Genus : Plasmodium
Species : Vivax

3. ABOUT PLASMODIUM
 Among the protozoans, Plasmodium is one of the most
harmful parasites of man. It is a digenetic, intracellular
parasite that lives in the liver cells and RBC of man.Its
primary host is the female Anopheles mosquito and the
secondary host is man. Reservoir host is monkey. The
infective stage is Sickle shaped sporozite and the mode
of infection is inoculation.
 4 species of plasmodium causes 4 types of malaria :
i. Plasmodium vivax – benign tertian malaria
ii. Plasmodium falciparum – cerebral malaria
iii. Plasmodium ovale – mild tertian malaria
iv. Plasmodium malariae – quartan malaria

4. STRUCTURE OF SPOROZOITE

5. LIFE CYCLE OF PLASMODIUM IN MAN
 In man, the plasmodium reproduces by asexual
reproduction called Schizogony. It occurs in liver cell as
well as in RBC. In liver cells, it is called hepatic
schizogony and in RBC it is called erythrocytic
schizogony.
 HEPATIC SCHIZOGONY : Whenever , a mosquito
infected by plasmodium bites a man, nearly 2000
sporozoites are released into blood of man through its
saliva. Within ½ hour, they reaches the hepatocytes
where they undergo Pre-erythrocyctic and exo-
erythrocytic cycles.

6. PRE – ERYTHROCYCTIC CYCLES

7. EXO- ERYTHROCYTIC CYCLE

8. PREPATENT PERIOD
The interval between ‘the first entry of
plasmodium into the blood in the form of sporozoites and
the second entry of Plasmodium into the blood in the form
of cryptozoites is called Prepatent period. It lasts
approximately 8 days. During the period, the host does not
show any clinical symptoms of the disease .It is only a
means of multiplication.

9. ERYTHROCYTIC CYCLE

10. INCUBATION PERIOD :
The period between ‘the entry of Plasmodium into
the blood in the form of sporozoite and the first appearance
of malaria in man’ is called Incubation period.

11. FORMATION OF GAMETOCYTES
 After repeated cycles of erythrocytic schizogony, when the
fresh RBC decreases, some merozoites enter the RBC and
transform into gametocytes instead of continuing the
erythrocytic cycle. This takes place when the RBCs are
present in spleen and bone marrow.
 The gametocytes are of 2 types namely, smaller
microgametocytes or male gametocytes and larger macro
gametocytes or female gametocytes.
 These cannot undergo further development in man as the
temperature and the pH of the blood of man are not suitable.
 They reach the blood circulation and wait to reach the next
host. They degenerate and die if they are not transferred to
mosquito within in a week.

13. LIFE CYCLE OF PLASMODIUM IN
MOSQUITO – ROSS CYCLE
When a female mosquito bites and sucks the
blood of a malarial patient, the gametocytes along with the
other stages of erythrocytic cycle reach the crop of
mosquito. Here all the stages are digested except the
gametocytes.
Further part of the life cycle consists of :
 Gametogony
 Fertilization
 Formation of Ookinete & Oocysts
 Sporogony

14. GAMETOGONY
 The formation of male and female gametes from the
gametogony. It occurs in the lumen of the crop of
mosquito.
FERTILIZATION
 The fusion of male and female gametes is called
fertilization. It also occurs in the lumen of the crop of the
mosquito.
FORMATION OF OOKINETIC & OOCYSTS
 The zygote remains inactive for sometime and then
transforms into a long,slender,motile,vermiform
ookinetic or vermicule within 18 – 24 hours.

15.  It pierces the wall of the crop and settle beneath the
basement membrane
 It becomes round and secretes a cyst around its body.
The encysted ookinetic is now called Oocyst
SPOROGONY
 The formation of sporozoites in the oocysts is called
Sporogony

20. LABARATORY TESTS
 Testing is performed to help diagnose malaria, to monitor for
relapses, and to determine drug susceptibility of the parasite causing
the infection.
 Thick and thin blood smears
Diagnosis of malaria involves performing blood smears. For a blood
smear, a drop of blood is applied to and spread onto a glass slide. It
is then treated with a special stain and examined under a microscope
for the morphology of infected blood cells and the parasite.
Typically, two thick smears and two thin smears are prepared. These
tests are currently the "gold standard" for malaria detection and
identification. They require examination by a trained and
experienced laboratorian.

21.  The number of malaria parasites present in the blood at a given time
fluctuates. Therefore, if no parasites are seen on the initial set of
smears and the health practitioner still suspects malaria, then
additional blood samples will be obtained to be tested. The samples
may be collected at 8 to 12 hour intervals over 2 to 3 days to
increase the probability of detecting the parasites. It is advantageous
if the sample collection coincides with the appearance of signs and
symptoms as this is the time that the parasites will most likely be
detected in the blood.
 Thick smears are a more sensitive test for malaria infection. A
greater volume of blood is examined under the microscope and the
parasites are therefore more likely to be seen. Thin smears have
fewer blood cells present and allow identification of the type
of Plasmodium species causing the infection. The number of
infected red blood cells can also be calculated to determine the
degree to which a person is infected (parasite load). This information
is essential for proper treatment.

22. RAPID DIAGNOSTIC TEST
 When microscopy is not readily available, rapid diagnostic tests may be
used instead of blood smears. These tests detect malaria antigens (proteins)
in a sample of a person's blood (usually taken with a fingerstick) and
indicate a positive result by a color change on the testing strip. They are
sometimes called "dipstick" tests.
 Different rapid diagnostic tests are available, and they have varying
capabilities in what they detect. For example, some rapid tests may detect
all four common species (P. falciparum, P. vivax, P. ovale, P. malariae) but
do not distinguish between them. Others are combination tests that can
detect all four common species and will identify P. falciparum specifically if
it is present. The type of rapid test used is dependent on the patient
population and the goals of providing a rapid test result.
 The U.S. Food and Drug Administration (FDA) has approved a rapid
diagnostic test for malaria. It is approved for use by hospital and reference
laboratories, but not for doctors' offices or home testing. This rapid test may
allow for faster diagnosis and treatment. However, it is recommended that
positive results be followed with blood smears for confirmation and to
determine the extent of infection.

23. MOLECULAR TEST( PCR )
The polymerase chain reaction is a laboratory method
that amplifies the parasite's DNA and allows detection and
identification of the Plasmodium species. This test can be used
to confirm the diagnosis in laboratories where there is a lack of
training and experience in the microscopic examination for
malaria. It can also be used to determine the Plasmodium species
if the results of a blood smear are unclear. Likewise, it is useful
for cases in which the number of malaria parasites in the blood is
low or when there are different types causing the infection
(mixed) and examination using a microscope may be less
accurate. The cost of these molecular testing techniques limits
their use in many regions where malaria is endemic.

24. ANTIBODY TEST ( SEROLOGY )
 Serology tests detect antibodies in the blood that
are produced by the body in response to a malaria
infection. They cannot diagnose an acute infection
but help determine if a person was previously
exposed. These tests are not routinely used in the
U.S. since a diagnosis can be made sooner by
detecting the parasite under the microscope or its
DNA instead of waiting for an immune response to
develop weeks later.

25. SUSCEPTIBILITY TESTING
Some malarial parasites have become resistant to the
drugs commonly used to treat the infections. Some
specialized laboratories can test the parasites from
an infected person to determine their drug
susceptibility. This can be done either by growing the
parasites in the presence of increasing amounts of
the drug and observing the effect of the drug on the
parasite or by testing the DNA of the parasite to
detect markers that indicate resistance. This latter
method is still being evaluated.