Malaria

Presentation on theme: "Malaria"— Presentation transcript:

Slide1

MalariaSlide2

Background

Definition of

malaria

Malaria is an infectious disease caused by protozoan organisms of the genus

Plasmodium

(

falciparum

,

ovale

,

vivax

,

malariae

). It is characterized by high fever and erythrocytic infection resulting in anemia..Slide3

life cycle:

asexual phase (schizogony)

sexual phase (sporogony)

Slide4

human host

There are four species of malaria that infect humans. All of them are transmitted in the same way,

Mosquito bites human

Sporozoites injected into human host during blood meal

Sporozoites infect liver cells, develop into schizonts, which release merozoites into the blood stream by rupturing the liver cells.

Merozoites penetrate red blood cells and form schizonts; red blood cells release merozoites

Some merozoites differentiate into male gametocytes or female gametocytes.

Gametocytes are taken in by mosquito from a blood meal.

Mosquito stage

Parasites undergo sexual reproduction, develop into oocysts which release sporozoites that invade the mosquito's salivary glands.

And the cycle continues on

……Slide5

Sporogonous Cycle

:

Mosquito Stages

Gametocytes

P. falciparum

P. vivax

P. ovale

P. malariae

Human Liver Stages

Exo-erythrocytic

(hepatic) Cycle:

Human Blood Stages

Erythrocytic Cycle

:

Malaria LifecycleSlide6

Epidemiology

Malaria is

the most

important cause of fever and morbidity in

the tropical world.Slide7

Clinical Manifestations

The clinical manifestations of malaria range from

asymptomatic infection to fulminant illness

and

.

Death

.

Febrile paroxysms

classic symptoms of the febrile paroxysms of malaria include high fever, rigors, sweats, and

V:48h

o:48h m:72h

headache.Slide8

:

Relapse

Short-term relapse

Longterm relaps Slide9

Malaria: Clinical manifestations

•

Febrile paroxysms have 3 classic stages

–

Cold stage

Pt feels cold and has shaking chills

-

mins. prior to fever

–

Hot stage

41°

Lassitude, loss of appetite, bone and joint aches

Tachycardia, hypotension, cough, HA, back pain,

N/V, diarrhea, abdo pain, altered consciousness– Sweating stageMarked diaphoresis followed by resolution of fever,

profound fatigue, and sleepinesshours after onset of hot stageSlide10

Malaria: Clinical manifestations

•

Other symptoms depend upon the strain of malaria

•

P. vivax, ovale and malariae: few other sxs

•

P. falciparum:

–

Dependent upon host immune status

No prior immunity/splenectomy high levels of parasitemia

: profound hemolysis

– Vascular obstruction and hypoxiaKidneys: renal failure

Brain: hypoxia, CNS dysfunction, coma, seizures

Lungs: pulmonary edema– Jaundice and hemoglobinuria (blackwater fever)Slide11

Laboratory and Imaging Studies

The diagnosis of malaria is established

by identification of

organisms on stained smears of

peripherd blood

.

timing of the smears is less important than their

being obtained

several times each day over 3

successive days.

.

Thick smears are used to scan large numbers of. Erythrocytes quicklyThin smears allow for positive identification

of the malaria species.Slide12

Diagnosis

Key of diagnosis is to identify P. falciparum

New assays:

–

ELISA for antigen, immunoassay for LDH,

PCR PCR

Anemia, elevated LDH, increased reticulocytes,

thrombocytopenia

Elevated unconjugated bilirubin without increases

in hepatic enzymes

Elevated serum creatinine, proteinuria,

hemoglobinuria, hypoglycemiaSlide13

Differential Diagnosis

the possibility of malaria in

any child

who has fever, chills, splenomegaly, anemia,

or decreased

level of consciousness with a history of

recent travel

or residence in an endemic area, regardless of the

use of

chemoprophylaxis

.

DDX: tuberculosis, typhoid fever, brucellosis, relapsing fever,infective endocarditis, influenza, polio, yellow fever,trypanosomiasis, kalaazar, and amebic liver abscess

. Slide14

All Plusmudim Species Except Chloroquine-Resistant P. Falciparum

Oral Drug

of Choice

chloroquine phosphate

Parenteral

Drug of

Choice

q

uinidine gluconateSlide15

chloroquine-Resistant P.

Falciparum

Oral

drug

of

Choice

Quinine sulfate pl

us tetracycline‘

Alterative

Oral

regimens:

Quinine sulfate plus pyrimethamine-sulfadoxineMefloquineAtovaquone

Plus proguanilSlide16

chloroquine-Resistant P. Falciparum

Parenteral Dnrg of

Choice:

Quinidine

gluconateSlide17

Primaquine phosphate

(after completion

of

chloroquine)

Prevention of Relapses: P. viva and P. ovaleSlide18

Complications

Cerebral malaria

:

is

a complication

of P.falciparum infection and

a frequent cause of death (20% to 40%),

Especially among

children and nonimmune

adults

occur among patients with intense parasitemia (~5%).

Other complications include splenic rupture,renal failure, severe hemolysis (blackwater fever), pulmonary

edema, hypoglycemia, thrombocytopenia, andalgid malaria (sepsis syndrome with vascular collapse).Slide19

Prognosis

Death may occur with any of the malarial species,

is most frequent with complicated P.

falciparum

malaria

.

The

likelihood of death is increased in children

with

preexisting health problems, such as measles,

intestinal parasites, schistosomiasis, anemia, and malnutrition.

Death is much more common in poor developing countries