BIOLOGY TREM 2(CHAPTER 13)

BY: YEO YIT JUAN(U6S)

Malaria

Causes Cause by a protoctist of the genus

Plasmodium .There are 4 known pathogenic species:

P. falciparum P. vivax P. ovale P. malariae P. knowlesi

Plasmodium

Parasite enter human body via vector transmission.

Life cycle of Plasmodium is quite complex& requiring 2 host- humans and mosquito.

Causes

Life cycle of Plasmodium

Mode of TransmissionPlasmodium is carried by

mosquito(Anopheles).Characteristic of Anopheles mosquito: Pale and dark mark on wings.Rest on a surface at a 45° angleMostly bite at night

Anopheles mosquito

Anopheles species in Malaysia:- A. donaldi A balabacensis A maculatus

Blood transfusions (sharing of unsterile needles)

Vertical transmission (from mother to fetus in utero)

Life cycle of Plasmodium

Mode of Transmission

Sign and Symptoms Fever i. 10-15 day after bitten.ii. Occur 3 days intervals. Shivering Vomiting Nausea Headache Muscle pain Sweating Anaemia (Rupture of

erythrocytes) Spleen enlargement i. May ruptureii. Cause internal haemorrhage

P. falciparum• Infect the brain• Resulting inflammation&

convulsions.

Life Cycle of Plasmodium

Life Cycle of Plasmodium

Multiple fission in

liver

Fusion of ♂and♀ gametes

in mosquito midgut Mosquito

takes a blood meal

(gametocytes ingest)

Some merozoites differentiate into ♂ and ♀ gametocytes

inside RBC

Merozoites infect

RBC

Merozoites produce *in the

liver cell

Mosquito take blood meal

(sporozotes inject into human and carried to liver)

Sporozoites

produce in cyst

Cyst formed on outside of gut wall

Rupture of liver cells release

merozoites

More merozoit

es produced

; RBC rupture

Multiple fission

Gametocytes in

human blood

Sporozoites in salivary gland of mosquito

**Zygote growth

Multiple fission

Cyst rupture,

sporozoites released

migrate

Life cycle stage in

mosquito

Life cycle stage in human

Symptoms

Symptoms appear

Treatment Quinine – derived from the bark of cinchona

tree.

Bark of Cinchona tree

Antimalarial drug(with side effect)

Treatment

Antimalarial drug Notes/Side effect

Choloroquine • Inhibit protein synthesis.• Effectiness repidly decreasing

because of drug-resistant forms of Plasmodium.

Proguanil • Slight hair lose, vomiting , nausea, mouth ulcers

• Inhibit sexual reproduction of Plasmodium.

Meploquine • Vomiting, dizziness, disturbed sleep

• Expensive• Very potent and strictly used for

resistant strains.

Artemisinin • Derived from Chinese herb(青蒿素 ) from the plant Artemisia annua.

• Very rapid action, preventing progression of the disease.

Treatment

Artemisinin-based combination therapy(ACT)

BEST TREATMENT

Artemisinin is used together with another drug which has a different mode of action and different biological target in the parasite.

Prevention 1) Mosquito Eradication-killing the insect vector will break the transmission cycle.Ways:-♫ Anopheles lays eggs in stagnant water- oil can be pour on the

surface, larvicide may added into water.♫ biological measure control- introducing larvae-eating fish into

ponds and irrigation canals//spraying Balcillus thuringiensis(a bacteria) on the water.

♫ Drain swamps, marshes and clearing vegetation.♫ Fogging/ sprying with insecticide in malaria-prone areas.

Prevention 2) Avoid being bitten by mosquitoes.Ways-♫ Sleeping beneath long-lasting insecticide-treated

(pyrethroids) nets(ITN)♫ Using mosquito repellent.♫ Indoor spraying with insecticide.

Prevention 3) Use of prophylactics(preventive drugs)

Example:-♫ Antimalarial drugs can be take before, during and after

visiting an area where malaria is endemic.♫ Drugs commonly use are:- chloroquine, proguanil and mefloquine.

Questions

THANK YOU

THE END !