3. Introduction
• Malaria is an infectious disease caused by the
parasites called Plasmodia.
• It is transmitted by the female anopheles mosquito.
• Before the link between malaria and female
anopheles mosquito was discovered( by Ronald
Ross), the dreaded disease was attributed to
supernatural influences such as angered deities, evil
spirits or the black magic of sorcerers.
• Later on , with the observation that malaria occurred
more often near the water logged areas, it was
attributed to miasma and effluvia from swamps(
hence its name mal aria= bad air).

4. Malaria Worldwide
• Malaria is widely distributed throughout tropical
regions of the world in Africa, Hispaniola, Central and
South America, Asia, the Middle East and Oceania.
• 41% of world’s population lives in malaria- endemic
areas.
• An estimated 700,000-3 million persons die of
malaria every year, 75% of them are African children.
• In areas of Africa with high transmission there are
about 2700 deaths per day, 2 deaths per minute.

7. The Malaria Parasite
Phylum: PROTOZOA
Class: SPOROZOA
Order: COCCIDIIDA
Family: PLASMODIIDAE
Genus: PLASMODIA
Subgenera: PLASMODIUM
Species: P. falciparum, P. vivax,
P. ovale, P. malariae

8. Classification of Malarial Parasite
• Only four species of the protozoan genus
Plasmodium usually infect humans: P.
falciparum, P. vivax, P. malariae, and P. ovale.
• P. falciparum and P. vivax account for the vast
majority of cases.
• P. falciparum causes the most severe
infection.

9. Pathogenesis
• Malaria develops via two phases: an exoerythrocytic
and an erythrocytic phase.
• An infected mosquito may pierce a person's skin to take
a blood meal.
• The sporozoites, present in the saliva of the mosquito,
enter the bloodstream and migrate to the liver.
• The sporozoites, in the liver cells, multiply asexually to
yield thousands of merozoites. This process is called
exoerythrocytic schizogony.
• This exoerythrocytic or liver phase of the disease usually
takes between 5 and 21 days, depending on the species
of plasmodium.

10. Pathogenesis contd.
• Following rupture of their host cells, thousands of
merozoites are released into the blood stream thus
beginning the erthrocytic stage.
• Each merozoite can infect a red blood cell. Within the
red blood cells, the parasites multiply further, again
asexually, periodically breaking out of their hosts to
invade fresh red blood cells.
• Some merozoites turn into male and female
gametocytes. If a mosquito pierces the skin of an
infected person, it potentially picks up gametocytes
within the blood. Fertilization of the parasite occurs in
the mosquito's gut. New sporozoites develop and travel
to the mosquito's salivary gland, completing the cycle.

12. Infected erythrocytes

13. Signs and Symptoms
• The general symptoms include fever , headache,
sweating, tiredness, abdominal pain, diarrhoea, loss of
appetite, jaundice, cough, vomiting etc.
• The time after which they develop depends on the type
of plasmodium that caused the infection.
• Symptoms may appear and disappear in phases and may
come and go at various time frames.
• Further serious complication involving the kidneys and
brain may develop leading to delirium and coma.

14. Diagnosis
• Malaria is considered a potential medical emergency.
Delay in diagnosis and treatment is a leading cause of
death in malaria patients in the United States.
• Definitive diagnosis of malaria generally requires direct
observation of malaria parasites in Giemsa-stained thick
and thin blood smears.
• Other diagnostic methods include assays to detect
malaria antibodies and antigens, and PCR/DNA and RNA
probe techniques.

15. P. vivax P. ovale
P. falciparum P. malariae

16. Treatment
Treatment of malaria depends on the following
factors:
• Type of infection
• Severity of infection
• Status of the host
• Associated conditions/ diseases

17. Treatment contd.
Aims Causation Therapy Drugs
To alleviate Symptoms are Blood Chloroquine,
symptoms caused by schizonticidal quinine,
blood forms of drugs artemisinin
the parasite combinations
Relapses are
due to Tissue
To prevent
hypnozoites of schizonticidal Primaquine
relapses
P. vivax/ P. drugs
ovale
Primaquine for
Spread is
To prevent Gametocytoci P. falciparum,
through the
spread dal drugs Chloroquine
gametocytes
for all other

19. Prevention
• Most cases of malaria in Americans can be prevented by
chemoprophylaxis and by avoiding the mosquito vector.
• The female Anopheles mosquito feeds from dusk until
dawn. During these hours, individuals should avoid
contact with the mosquito by wearing protective
clothing, using an insect repellent and by sleeping under
insecticide-impregnated bed nets.

21. Resistance
• Resistance of P. falciparum to chloroquine, the
cheapest and most used drug, is spreading in almost all
the endemic countries. Resistance to the combination
of sulphur doxine- Pyrimethamine is also prevailing.
• Resistance occurs most commonly due to improper
treatment and inadequate dosage of antimalarial drug.
• Possible mechanisms- The parasite does not allow the
entry of drug or after the entry of drug the malarial
parasite does not retain it and throws it out.

23. Molecular Tools
• Improved diagnostic tools, especially molecular biology-
based tools, to support the clinical suspicion of malaria
are developed.
• Nucleic acid-based diagnostic methods for parasitic
infections have been developed over the past 12 years.
PCR-hybridization assays, PCR-restriction fragment
length polymorphism (PCR-RFLP) assays and random
amplified polymorphic DNA (RAPD) analysis have
proved valuable for epidemiological studies of parasites.

24. Molecular Tools contd.
Species-specific PCR diagnosis of malaria:-
• Detection and speciation of Plasmodium is done with
a two step nested PCR.
• In the first step (PCR1), 1 µl of extracted DNA is
amplified using genus specific primers.
• In the second step (PCR2), 1 µl of PCR1 amplification
product is further amplified using species specific
primers.
• 10 µl of each PCR2 amplified DNA product is
separated by 2% agarose gel electrophoresis, stained
for 15 min with ethidium bromide and visualized by
UV illumination.

25. Lane 1: P. vivax (size: 120 bp).
Lane 2: P. malariae (size: 144 bp).
Lane 3: P. falciparum (size: 205 bp).
Lane 4: P. ovale (size: 800 bp).

26. Conclusion
• Each year, there are more than 225 million cases of malaria,
killing around 781,000 people which contributes to 2.23% of
deaths worldwide.
• Its really a high time to overcome that “female” mosquito
and accordingly taking measures to prevent its harmful
effects on our lives.

27. References
• www.malariasite.com
• www.wikipedia.org
• www.cdc.gov
• Google images

28. Any Questions?