Malaria is a mosquito-borne parasitic disease caused by Plasmodium parasites. It affects over 100 tropical and subtropical countries and causes hundreds of millions of cases and millions of deaths annually. The disease is transmitted via the bites of infected female Anopheles mosquitoes. It has a complex life cycle involving sexual reproduction in the mosquito and asexual reproduction in human hosts. Symptoms vary depending on the Plasmodium species but can include fever, chills, flu-like illness, and in severe cases organ damage or death. Diagnosis is via blood smear microscopy or rapid antigen tests. Prevention focuses on mosquito control and use of insecticide-treated bed nets, while treatment involves antimalarial medications

1. Shanyar Kadir
Shkar Dilshad
Shvan Omar

2. What does Malaria mean?

The word “malaria” comes from the Italian
mala aria, meaning “bad air.” When the term
was coined, it was commonly believed that
malaria was caused by breathing in bad air.

3. Overview

 Malaria is a mosquito-borne parasitic disease caused
by genus Plasmodium, affecting over 100 countries
of the tropical and subtropical regions of the world.
 Around 400-900 million people are affected
 At least 2.7 million deaths annually.
 It is one of the major public health concerns

4. Epidemiology

 Around 300-500 million clinical cases of malaria are
reported every year, of which more than a million die of
severe and complicated cases of malaria.
 Malaria is known to kill one child every 30 sec, 3000
children per day under the age of 5 years.
 Malaria ranks third among the major infectious diseases
in causing deaths after pneumococcal acute respiratory
infections and tuberculosis, and accounts for
approximately 2.6% of the total disease burden of the
world.

5. 

6. Epidemiology (cont.)

 It mainly occurs throughout tropical regions
 515 million clinical cases per year
 An estimated 655,000 people died from malaria in
2010
 with two-thirds of these occurring in sub-Saharan
Africa
 especially amongst children and pregnant women
 the incidence of malaria was greatly reduced
between 1950 and 1960
 but since 1970 there has been resurgence.

7. Who is at Risk?

 Most people who get
malaria are travelers or
people who live in an
area with malaria
transmission.
 Young children and
pregnant women.
 Poor people that live in
rural areas who lack
knowledge, money and
the access to health care.

8. Causative Agent

 Malaria is caused by species of Plasmodium.
 The genus Plasmodium contains over 200 species
 at least 11 species infect humans. Most important are:
 Plasmodium falciparum
 Plasmodium malariae
 Plasmodium ovale
 Plasmodium vivax
 Plasmodium knowlesi
 Plasmodium parasites are highly
specific with female Anopheles mosquitoes

9. Vector

 Female mosquitos of genus Anopheles are primary
hosts and transmission vectors.
 There are approximately 460 recognized species
 Over 100 can transmit human malaria
 Only 30–40 commonly transmit parasites of the
genus Plasmodium
 Anopheles gambiae is one of the best known which
transmits Plasmodium falciparum

10. Vector (cont.)

Only female mosquitoes feed on blood while
the males feed on plant nectar and do not
transmit the disease.
The females of Anopheles genus prefer to
feed at night
They start searching for a meal at dusk and
continue throughout the night until they take
a meal

11. Life Cycle


12. Life Cycle & Pathogenesis

 Inside the vector (sexual reproduction):
 Young female mosquitoes ingest the malaria parasite by
taking a blood meal from an infected human carrier
 The ingested gametocytes will differentiate into male and
female gametes and then unite to form a zygote (ookinete)
in the mosquito’s gut
 The resulting ookinete penetrates the gut lining to form
an oocyst in the gut wall
 The oocyst ruptures to release sporozoites that migrate in
the mosquito’s body to the salivary glands and are ready
to infect new human hosts

13. Life Cycle & Pathogenesis

Inside humans:
 Malaria develops via two phases:
 Exoerythrocytic: involves infection of liver
 Erythrocytic phase: involves infection of RBC
(erythrocytes)

14. Life Cycle & Pathogenesis
 by taking a blood meal.
 A mosquito infects a person
 First, sporozoites enter the bloodstream, and migrate
to the liver. They infect liver cells (hepatocytes),
where they multiply into merozoites, rupture the
liver cells, and escape back into the bloodstream.
 Then, the merozoites infect red blood cells, where
they develop into ring forms, trophozoites and
schizonts which in turn produce further merozoites.
 Sexual forms (gametocytes) are also produced,
which, if taken up by a mosquito, will infect the
insect and continue the life cycle.

15. 

16. Clinical Features

 P. falciparum (malignant tertian):
 It is the most dangerous of the malarias
 Onset is insidious, with malaise, headache and
vomiting… commonly mistaken for influenza
 The fever has no particular pattern.
 Jaundice is common due to hemolysis & hepatic
dysfunction
 There is hepatosplenomegaly
 Anemia develops rapidly

17. Clinical Features

 P. falciparum complications:
 Cerebral Malaria: the most grave complication, causing
either confusion or coma without localizing signs.
 Convulsions
 Hypoglycemia
 Acute pulmonary edema
 Acure renal failure (Blackwater fever )
 Metabolic acidosis
 Aspiration pneumonia
 Severe anemia
 Coagulopathy/Spontaneous bleeding

18. Causes of severe malaria

 P. falciparum-infected
erythrocytes sequester in blood
vessels, creating blockages.
 Infected erythrocytes also “stick to
endothelium, platelets, and other
erythrocytes”
 Rosetting -- cohesion of
erythrocytes
 Leads to immune evasion because
of lack of circulation through the
spleen.
 Aids in the progression of the
severity of malaria

19. Clinical Features

 P. vivax & P. ovale (benign tertian):
 In many cases the illness starts with several days of
continued fever before the development of classical
bouts of fever on alternate days. Fever starts with a
rigor. The patient feels cold and the temperature
rises to about 40 C. After an hour hot or flush phase
begins. It lasts several hours and gives way to
profuse perspiration and a gradual fall in
temperature. The cycle is repeated 48 hours later.
 Anemia develops slowly

20. Clinical Features

P. malariae infection (quartan):
 This is usually associated with mild symptoms and
bouts of fever every third day. Parasitemia may
persist for many years with the occasional recurrence
of fever, or without producing any symptoms.

21. Hypnozoites

 It is the round or oval, uninucleate, dormant form of
Plasmodium seen inside the liver cells during the
intrahepatic (exoerythrocytic) stage of the parasite’s
life cycle; it is believe to be the true latent stage
associated with relapse in malaria.
 Hypnozoites are seen in:
 Plasmodium vivax
 Plasmodium ovale

22. Diagnosis
 Clinical

 Fever, sweat, chills, headache and muscle pain
 Serology
 PCR
 ELISA
 Blood Film (gold standard)
 Banana-shaped intraerythrocytic gametocytes identify P.
falciparum
 Enlarged erythrocytes with Schuffner’s dots are
characteristics of P. vivax
 Schuffner’s dots in ovale-shaped red blood cells are
characteristic of P. ovale
 Band-form trophozoites are seen in P. malariae

23. 

24. BinaxNOW® Malaria

 Detects circulating
malaria antigens in
whole blood.
 15 minute test
 The only FDA cleared
rapid malaria test.

25. How the test works?

 The test targets the histidine-rich protein II (HRPII)
antigen specific to P. falciparum and a pan-malarial
antigen (aldolase), common to all four malaria
species capable of infecting humans - P. falciparum,
P. vivax, P. ovale, and P. malariae.
 It is intended to aid in the rapid diagnosis of human
malaria infections and to aid in the differential
diagnosis of Plasmodium falciparum infections from
other less virulent malarial infections. Negative
results must be confirmed by thin / thick smear
microscopy.

26. Prevention

 Medications (will be mentioned in treatment)
 Vector control
 Mosquito nets and bedclothes
 Immunity (natural & vaccines)
 Education

27. Vector Control

 Efforts to eradicate malaria by eliminating
mosquitoes have been successful in some areas.
Malaria was once common in the United States and
southern Europe, but vector control programs, in
conjunction with the monitoring and treatment of
infected humans, eliminated it from those regions.
 Malaria was eliminated from most parts of the USA
in the early 20th century by use of the pesticide DDT.

28. Mosquito nets

 Mosquito nets help keep mosquitoes away from people
and greatly reduce the infection and transmission of
malaria. The nets are not a perfect barrier and they are
often treated with an insecticide designed to kill the
mosquito before it has time to search for a way past the
net. Insecticide-treated nets (ITNs) are estimated to be
twice as effective as untreated nets and offer greater than
70% protection compared with no net. Since the
Anopheles mosquitoes feed at night, the preferred
method is to hang a large "bed net" above the center of a
bed such that it drapes down and covers the bed
completely.

29. Immunity

 Natural immunity occurs, but only in response to
repeated infection with multiple strains of malaria.
 A completely effective vaccine is not yet available for
malaria, although several vaccines are under
development.
 SPf66 was tested extensively in endemic areas in the
1990s, but clinical trials showed it to be insufficiently
effective.
 Other vaccine candidates, targeting the blood-stage of the
parasite's life cycle, have also been insufficient on their
own.
 Several potential vaccines targeting the pre-erythrocytic
stage are being developed.

30. Vaccines

First proposed in 1960s, still nothing fully effective
Difficulties include :
 Intracellular parasites
 Polymorphism and clonal variation
 Parasite induced immunosuppression
 Antigenic variation
 Evaluation and trials difficult to interpret
 High level of parasite mutation

31. Education
 symptoms of malaria
 Education in recognizing the
has reduced the number of cases in some areas of the
developing world by as much as 20%.
 Recognizing the disease in the early stages can also
stop the disease from becoming a killer.
 Education can also inform people to cover over areas
of stagnant, still water which are ideal breeding
grounds for the parasite and mosquito, thus cutting
down the risk of the transmission between people.
 This is most put in practice in urban areas where
there are large centers of population in a confined
space and transmission would be most likely in these
areas.

32. Treatment

 When properly treated, a patient with malaria can expect
a complete recovery. The treatment of malaria depends
on the severity of the disease; whether patients can take
oral drugs or must be admitted depends on the
assessment and the experience of the clinician.
 Uncomplicated malaria is treated with oral drugs. The
most effective strategy for P. falciparum infection
recommended by WHO is the use of artemisinins in
combination with other antimalarials artemisinin-
combination therapy, ACT, to avoid the development of
drug resistance against artemisinin-based therapies.

33. Treatment

 Severe malaria requires the parenteral administration of
antimalarial drugs. Until recently the most used treatment
for severe malaria was quinine but artesunate has been
shown to be superior to quinine in both children and
adults. Treatment of severe malaria also involves
supportive measures.
 Infection with P. vivax, P. ovale or P. malariae is usually
treated on an outpatient basis. Treatment of P. vivax
requires both treatment of blood stages (with chloroquine
or ACT) as well as clearance of liver forms with
primaquine.

34. Chemoprophylaxis
Antimalarial tablets
dose
Chloroquine resistance high

Adult prophylactic Regimen
Mefloquine 250mg weekly Started 2-3 weeks before
travel and continued until
4 weeks after
or Doxycycline 100mg daily Started 1 week before and
continued until 4 weeks
after travel
Or Malarone 1 tablet daily From 1-2 days before
travel until 1 week after
return
Chloroquine resistance absent
Chloroquine 300mg base weekly Started 1 week before &
and proguanil 100-200mg daily continued until 4 weeks
after travel

35. 

36. Thank You!
