MALARIA

OPTOM FASLU MUHAMMED

Malaria is a mosquito born infectious disease of human and other animals caused by eukaryotic protists of the genus plasmodium.

The disease results from the multiplication of plasmodium parasites within RBC

Main species plasmodium falciparum (severe disease), plasmodium vivax, plasmodium ovale.

Symptoms

FeverMuscular fatigue and painHeadache- centralBack painSkin- chills and shiveringIn severe cases progressing to coma or deathArthralgia (joint pain)

VomitingAnemiaJaundiceHemoglobinuriaRenal damageSpleen enlargementDry mouth

Classical symptoms:-Cyclical occurrence of sudden coldness

followed by rigor and then fever and sweating lasting 4 – 6 hrs

Occuring every 2 days in plasmodium vivax and plasmodium ovale infections

And every 3 days for plasmodium falciparum infection.

Signs

Abnormal posturingSevere back painNeurological damage in cerebral malariaRetinal whitening

Severe malaria caused by plasmodium falciparum usually arises 6 – 14 days after infection

Consequences: coma, death if un-treatedYoung children and pregnant woman are

especially vulnerable.Splenomegaly, headache, cerebral ischemia,

hepatomegaly, renal failure

Transmission

Female anopheline mosquitoTransfusionCongenitalDirty needlesOrgan transplant

Female mosquito of the Anopheles genus are the primary or definitive host and act as transmission vectors.

Young mosquitoes first ingest the malaria parasite feeding on an infected human carrier and the infected Anopheles mosquito carry plasmodium parasite in their salivary gland.

A mosquito becomes infected when it takes a blood meal from an infected human.

This produces an ookinete that penetrate the gut lining and produces an oocyte in the gut wall.

When the oocyte repture it release sporozois

That migrates the mosquitoes body to the salivary gland.

Pathogenesis

Mosquito infect a person by taking a blood meal

First sporozoits enter the blood steam and migrate to the liver.

The infect liver cells (hepatocytes) where they multiply into merozoites, repture the liver cells and escape back into the blood stream

Then the merozoites infect the RBC

Malaria develops via 2 phases: an exo-erythrocytic phase and erytrocytic phase.

The exo-erythrocytic phase involves infection of the hepatic system.

The erytrocytic phase involves the infection of the erythrocytes or RBC.

Life cycle

Ocular manifestation

Conjunctiva: sub conjunctival hemorrhageNerve: paralysis of III, IV, VI cranial nervesIris: anisocoriaLens: cataractVitreous: hemorrhage, opacityRetina: proliferative retinitisOptic nerve: optic atrophy, Papilloedema,

papillitis, optic neuritisField: scotoma

Complications

Acute Cerebral malaria Dic Atn Ards Severe hemolysis

Chronic Spontaneous splenic rupture Nephrotic syndrome

Diagnosis

Peripheral smearSerologyInvestigation of saliva or urineAntigen test or PCR

Banana shaped-gametocyteRound gametocyte

Rings

gametocyte

Trophozoite (not a ring)

Round gametocyte

Ring

Trophozoite

TreatmentTreatment of the malaria depends on the

severity of the diseaseAnti malarial drugs like: Malarone,

TafenoquineQuinine for severe casesUn-complicated malaria can be treated with

oral drugs

To control

Mosquito eradicationPrevention of mosquito bitesUse mosquito nets and spraying insecticides