Manoj Mahato

1. PLASMODIUM
MR.MANOJMEHTA -CLINICALMICROBIOLOGIST

2. P . vivax and P . falciparum are more common.
P . ovale is the rarest of the four soecies
More than 200 million people are infected worldwide
1 million deaths per year.
It is the most common lethal infectious disease.
Mostly found in tropical and subtropical areas especially Asia, Africa, Central and
South America, certain regions of South East Asia, South America and East Africa.
Chloroquine resistant strains of P . falciparum are found in these regions
GEOGRAPHICAL DISTRIBUTION

3. 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.
WHO IS AT RISK ?

4. Sir
LAVERN AND RONALD ROSS PIONEERED THE EVENTS ON MALARIA
HISTORY

5. Malaria is probably one of the oldest diseases known to mankind that has had
profound impact on our history.
It is a huge social, economical and health problem, particularly in the tropical
countries.
Malaria is a vector-borne infectious disease caused by single-celled protozoan
parasites of the genus Plasmodium.
Malaria is transmitted from person to person by the bite of female mosquitoes
INTRODUCTION

6. INTRODUCTION
Members of class Sporozoa are parasite so locomotory organs are absent in Plasmodium.
Members of order Haemosporidia show digenetic life cycle i.e. Plasmodium
completes its life cycle in two hosts
Primary host- Female Anopheles; where it completes mainly its sexual cycle.
Secondary host-Human being; where it completes it asexual life cycle
Reservoir host- Monkey
Eradication of Plasmodium is not easy due to its several host.
Another reason is that vaccine can’t be formed because,Plasmodium don’t induce human body to form
antibodies and hence no immunity against Plasmodium can develop.

7. 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.
Most important cause of fever and morbidity in the Tropical world
Malaria has been eradicated from Europe, Most of North America, USA South America Korea and Japan
P. vivax is most commonly distributed and prevails in the temperate regions of the world.
There are four distinct species of the Plasmodium parasite that affect humans:
o Plasmodium vivax
oPlasmodium malariae
oPlasmodium ovale
oPlasmodium falciparum
 Plasmodium falciparum is the greatest threat to public health, and also the most life threatening.
INTRODUCTION

8. Its life cycle passes through two different hosts :
Intermediate host (a vertebrate- man or other animals)
 Asexual multiplication (schizogony) takes place
Sexual multiplication (gametogony) starts and gives rise to gametocytes (infective to definitive host).
Definitive host (an invertebrate - female Anopheles mosquito)
Sexual multiplication (sporogony) takes place and gives rise to Sporozoites (infective to intermediate host
Sporozoites are infective forms Present in the salivary gland of female anopheles mosquito
 After bite of infected mosquito sporozoites are introduced into blood circulation
This is an intracellular blood parasites.
INTRODUCTION

9. It is transmitted by Bite of a female Anopheles mosquito that had contact with another individual
infected with malaria
By sporozoites: Bite of infected female Anopheles mosquito containing sporozoites in their salivary
glands.
By trophozoites: Transfusion of blood from a person containing trophozoites.
Transplacental transmission.
Using infected needles/syringes.
MODE OF TRANSMISSION

10. Time taken from infection to symptoms is known as Incubation period.
• Plasmodium falciparum 6-12 days
• Plasmodium vivax 10-17 days
• Plasmodium ovale 12-16 days
• Plasmodium malariae 28-30 days
INCUBATION PERIOD

11. LIFE CYCLE OF PLASMODIUM

13. LIFE CYCLE OF PLASMODIUM

14. Divided into 3 stages-
-Life cycle in man(schizogony)
1. Exoerythrocytic stage – in liver of man.
2. Erythrocytic stage- in RBCs of man.
-Life cycle in mosquito(sporogony)
3. Sporogonic stage- in mosquito (female Anopheles)
LIFE CYCLE OF PLASMODIUM

15. When female anopheles mosquito penetrate human skin to obtain blood meal, it inject saliva
mixed with a anti coagulant .
If mosquito is infected with plasmodium it will inject elongated sporozoits to the blood stream
of the victim.
LIFE CYCLE OF PLASMODIUM

16. The sporozoites travel to the liver where enter into the liver cell and divide asexually which
is called schizogony generates the next life cycle form called merozoits.
This cycle lasting approximately 8days in P.vivox,6days in P. falciparum, 9days in ovale
PRE- ERYTHROCYTIC SCHIZOGONY
LIFE CYCLE OF PLASMODIUM

17. The released merozoite invade other liver cell and enter the host blood stream and invade
erythrocytes and the merozoites begins to enlarge as uninucleate cell termed as ring trophozoite.
The merozoite then divides asexually to produce schizont which contain several Nuclei
and the schizont then divides and produce mononucleated merozoites.
The erthrocytes then rapture and releases toxins throughout the body of the host bringing about
the will known cycle of fever cold chill that is the characteristics of malaria.
This cycle lasting approximately 48-72 hrs in P.vivox,48hrs in P.falciparum, and in P.ovale also
while 72 hrs in P. malarie.
The liberated merozoites re enter into new RBC and the cycle continue for several times
After several cycles, the liberated merozoites loose their capacity to re invade RBC and begin
gametogenesis
ERHTHROCYTIC SCHIZOGONY
LIFE CYCLE OF PLASMODIUM

18. Plasmodium enter to sexual phase when some of the merozoites in RBC develop into
gametocytes and become capable of producing both male and female gametes within the
human hosts and extracted from the infected host by a mosquito
Within the gut of mosquito the gametocytes form male and female gametes and the resultant
diploid zygote develop within the mosquitoes intestinal wall and differentiated into oocyte
In the oocyst mitotic division occur producing large number of sporozoite which migrates
then to the saliva of the female anopheles and injected to the blood stream of the host
GAMETOGONY
LIFE CYCLE OF PLASMODIUM

19. Gametocytes are not responsible for fever.
The individual who hourbours gametocytes is known as carrier.
Exo -Erythrocytic schizogony (in hepatocytes):
Occurs only in P. vivax and P. ovale.
The parasite in this stage is known as hypnozoite.
Hypnozoite can be transformed into merozoite at any time.
Erythrocytic parasite can not transformed into hypnozoite.
Hypnozoite is responsible for relapse of malaria in P. vivax and P. ovale.
LIFE CYCLE OF PLASMODIUM

20. Symptoms usually appear about 1to 3 weeks after infection.
People with malaria will have many but not generally all of the
following symptoms:
Fever has three stage :
ocold stage
ohot stage
osweeting stage and chills
oabdominal pain
odiarrhea, nausea, and vomiting
SIGN AND SYMPTOMS OF MALARIA

21. CLINICAL DIAGNOSIS OF MALARIA
CLINICAL CASE DESCRIPTION:
 Fever case with any of the following:
 Chills,
 Sweating,
 Jaundice,
 Splenomegaly
 Convulsions,
 Coma,
 Shock,
 Pulmonary edema and
 Death (in severe cases)

22. Cerebral malaria
Malarial hyperpyrexia
Gastrointestinal disorders.
Algid malaria
Black water fever can lead to death
Can produce Nephrotic syndrome
COMPLICATIONS OF MALARIA

23. Infection with Plasmodia causes intermittent fevers which are known as malaria
Each of the four species causes a characteristic fever and the disease are designated as follows
P. vivax – Benign tertian malaria (Vivax malaria)
P. malariae – Quartan malaria (Malariae malaria)
P. falciparum – Malignant tertian malaria (Falciparum malaria)
P. ovlae – Ovale tertian malaria (Ovale malaria)
TYPES OF MALARIAL FEVER

24. LAB. DIAGNOSIS OF MALARIA

25. Laboratory diagnosis of malaria is confirmed by the demonstration of malarial parasites in the
blood film under microscopic examination.
Microscopic examination, visualization of the parasite on the thick and/or thin blood smears “gold
standard” for malaria diagnosis.
Microscopic Examination of peripheral blood film after staining by Leishman stain.
Specimen is peripheral blood.
Blood must be collected during rising temperature or when temperature has reached the peak.
2 types of peripheral blood films that can be prepared thin film and thick film.
LAB. DIAGNOSIS OF MALARIA
MICROSCOPIC EXAMINATION

26. MICROSCOPIC EXAMINATION
LAB. DIAGNOSIS OF MALARIA
THICK FILM
• lysed RBCs
• larger volume
• 0.25 μl blood/100 fields
• good screening test
• positive or negative
• parasite density
• more difficult to diagnose
species
THIN FILM
• fixed RBCs, single layer
• smaller volume
• 0.005 μl blood/100 fields
• good species differentiation
• requires more time to read
• low density infections can be
missed

27. RING STAGE
MICROSCOPIC EXAMINATION
LAB. DIAGNOSIS OF MALARIA

28. RING STAGE
MICROSCOPIC EXAMINATION
LAB. DIAGNOSIS OF MALARIA
-Red nucleus on the ring-like light blue cytoplasm(large, 2.5 μm)

29. SCHIZONTS
MICROSCOPIC EXAMINATION
LAB. DIAGNOSIS OF MALARIA
-Nucleus divided into 12-24 ;and cytoplasm also divided, each nucleus surrounded
by aportion of cytoplasm to form merozoites,malarial pigment clumped.
-Absent in P. falciparum

30. GAMETOCYTES
MICROSCOPIC EXAMINATION
LAB. DIAGNOSIS OF MALARIA
Male gametocyte
Sausage in shape; 1 loose nucleus in center Of it ; malarial pigment diffuse.
Female gametocyte
Crescentic in shape ; 1 compact nucleus in Centre of it
-P. falciparum is the largest and is banana shaped, while others are smaller and round

31. Quantitative Buffy coat
LAB. DIAGNOSIS OF MALARIA
QUANTITATIVE BUFFY COAT(QBC)

32. Useful for screening large numbers of samples
Quick, saves time
Requires centrifuge, special stains
Malaria parasite floresce green yellow against dark red –black background.
3 main disadvantages
Species identification and quantification difficult
High cost of capillaries and equipment
Can’t store capillaries for later reference
LAB. DIAGNOSIS OF MALARIA
QUANTITATIVE BUFFY COAT(QBC)

33. Detection of antigen.
Detection of antibody.
Both the antigen and antibody are detected by Immune
Immune chromatographic test (ICT) – Routinely done, high
sensitivity & specificity, cheap, rapid, don’t require sophisticated or
expensive equipment's or reagents, available in Bangladesh in some
cases its positive even in patients whose PBF don’t reveal any
plasmodium.
Cannot detect mixed infections
Cross reactivity with rheumatoid factor reportedly corrected
LAB. DIAGNOSIS OF MALARIA

34. Serology (indirect immunofluorescence ‘IFA’ and enzyme-linked immunosorbent assay
‘ELISA’).
Detection of antigen.
Detection of antibody
LAB. DIAGNOSIS OF MALARIA

35. Polymerase Chain Reaction(PCR)
PCR can be done to detect specie.
Molecular technique to identify parasite genetic material
Uses whole blood collected in anticoagulated tube or directly onto filter paper
Threshold of detection 5 parasites/μl
Definitive species-specific diagnosis now possible
Can identify mutations – try to correlate to drug resistance
LAB. DIAGNOSIS OF MALARIA

36. CHEMOPROPHYLAXIX

37. TREATMENT OF MALARIA
 Quinine disrupts erythrocytic schizogony; no effect on sporozoites or exoerythrocytic
schizogony.
 Chloroquine drug of choice against non resistant malaria; no adverse side-effects.
Acts on sporozoites and erythrocytic schizogony.
 Primaquine acts on exoerythrocytic schizogony, not used to replace others because it is toxic.
 Mefloquine  widely used; used for chloroquine resistant strains of P. falciparum; acts on
sporozoites; schizonts; exo-erythrocytic schizonts and gametocytes, but people don’t react to it
very well lots of side effects

38. Take steps to prevent mosquito bites.
Avoid spending time outdoors in hot weather.
Pregnant women should take extra steps to prevent malaria.
Wear protective clothing.
Drape mosquito nets over your bed at night.
At home, use mosquito traps
Using protective measures such as mosquito nets, antimosquito creams.
 Use of the prophylactic drugs; small daily dose of antimalarial drugs will kill the parasite either in the sporozoite or
merozoite stage
The young stages of mosquito can be controlled byintroducing some fishes like Gumbusia and Lebistes in ponds,
lakes, canals and tanks.
PREVENTION AND CONTROL

39. PREVENTION AND CONTROL