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Presentation on theme: "MALARIA"— Presentation transcript:
Slide1
MALARIA
Slide2
Over view
Basic understanding of malaria
Epidemiology
Symptoms
Diagnosis
Treatment
Prevention
Slide3
Malaria is a protozoan disease transmitted by the bite of
infected female Anopheles
mosquitoes.
Protozoan parasites of the genus
Plasmodium
Four species:
P
falciparum
P
vivax
P
ovale
P
malariae
Slide4Slide5Slide6
characteristic
p.falciparum
p.vivax
p.ovulae
p.malariae
Severity of malaria
Severe may be fatal
Benign,
rarely same
Uncommon,
benign
Mild,occasional
Duration of intra
hepatic phase
5.5
8
9
15
Average incubation period
7-14 days
12-17 days
15-18 days
18-40days
Duration of
erythrocytic
cycle
48
48
50
72
Red cell
preference
Younger cells
Rbc
up to 14 days
recticuocytes
Older cells
Slide7
Transmission
Man is the only important reservoir
Vector is female
Anopheles
mosquito
Temperature: below 86º F, above 68º F
Rainfall: thrive in tropical areas
Altitude: rarely exist above 2000 meters
Terrain: coastal areas and lowlands with
lots of freshwater breeding sites
Slide8
Transmission
Mosquito vector:
ANOPHELES
Transmission also possible through:
Blood transfusion
Contaminated needle
Organ transplant
Congenital
Slide9
Susceptibility
Universal susceptibility
No absolute immunity
Partial immunity in areas of high
endemicity
Slide10
Pathogenesis
RBC destruction
Immune complexes and mediators
Capillary permeability
Tissue hypoxia
Slide11
RBC Distruction
After invading an erythrocyte, the growing malarial parasite progressively consumes and degrades intracellular proteins, principally hemoglobin.
The potentially toxic
heme
is polymerized to biologically inert
hemozoin
, or malaria pigment.
The parasite also alters the RBC membrane by changing its transport properties, exposing cryptic surface antigens, and inserting new parasite-derived proteins.
The RBC becomes more irregular in shape, more antigenic, and less deformable.
Slide12
In P.
falciparum
infections, membrane protuberances appear on
the erythrocyte's surface toward the end of the first 24 h of the
asexual cycle. These “knobs” extrude a high-molecular-weight,
antigenically
variant, strain-specific, adhesive protein
(PfEMP1) that mediates attachment to receptors on
venular
and
capillary endothelium—an event termed
cytoadherence
.
Slide13
P.
falciparum
–infected RBCs may also adhere to uninfected
RBCs to form rosettes and to other parasitized erythrocytes
(agglutination). The processes of
cytoadherence
,
rosetting
, and
agglutination are central to the pathogenesis of
falciparum
malaria. They result in the sequestration of RBCs containing
mature forms of the parasite in vital organs (particularly the
brain), where they interfere with microcirculatory flow and metabolism.
Slide14
P.
vivax
, P.
ovale
, and P.
malariae
show a marked predilection
for either young RBCs (P.
vivax
, P.
ovale
) or old cells (P.
malariae
) and produce a level of
parasitemia
seldom >2%, P.
falciparum
can invade erythrocytes of all ages and may be
associated with very high levels of
parasitemia
.
Slide15
IMMUNE RESPONE
The specific immune response to malaria eventually controls the infection and, with exposure to sufficient strains, confers protection from high-level
parasitemia
and disease but not from infection.
As a result of this state of infection without illness (
premunition
), asymptomatic
parasitemia
is common among adults and older children living in regions with stable and intense transmission (i.e.,
holo
- or
hyperendemic
areas).
Immunity is mainly specific for both the species and the strain of infecting malarial parasite. Both
humoral
immunity and cellular immunity are necessary for protection, but the mechanisms of each are incompletely understood
Slide16
Plasmodium Species
P.
falciparum
Most severe and prevalent
40-60% of cases
Widespread CHLOROQUINE resistance
Infects RBCs of all ages—Heavy
parasitemia
Slide17
P.
vivax
30-40% of cases
Liver phase
INFECTS YOUNG RBCs: LESS SEVERE THAN FALCIPARUM
P.
ovale
Liver phase
INFECTS YOUNG RBCs
P.
malariae
Can persist SUBCLINICALLY for extended periods of time
INFECTS OLD RBCs
Slide18
Presentation
Fever 96%
Chills 96%
Headache 79%
Muscle Pain 60%
Palpable liver 33%
Palpable Spleen 28%
Nausea or vomiting 23%
Abdominal pain
/diarrhea 06%
Slide19
Complicated Malaria
Hyperparisitemia
: (>3%)
Hypoglycemia: (<60 mg/dl)
Severe anemia (
hct
< 21% or rapidly falling
hct
)
Renal failure
Hyponatremia
Cerebral malaria
Prolonged hypothermia
High output vomiting or diarrhea
Pregnancy
Slide20
DIAGNOSIS
Gold standard: Multiple thick and thin smears
Dip stick tests
CBC
Anemia
Leukopenia
, or
leukocytosis
No
eosinophilia
Slide21Slide22
Treatment
CHLOROQUINE sensitive infections:
CHLOROQUINE 600 mg (2 tabs) P.O. initially
300 mg (1 tab) in 6 hrs
300 mg (1 tab) QD for 2 days
Slide23
Uncomplicated CHLOROQUINE-resistant infections:
Quinine 650 mg PO TID x 3 days and DOXYCYCLINE 100 mg PO bid x 7 days,
OR
MEFLOQUINE 1000-1500 mg PO once
Complicated or severe
infections
I.V. QUINIDINE or quinine
Slide24
VIVAX
and
OVALE
therapy should include
PRIMAQUINE
15mg PO QD x 14 days
CDC now recommends:
PRIMAQUINE
30mg PO QD x 14 days
Slide25
Treatment Options
For
chloroquine
sensitive
Chloroquuine
Primaquine
For
chloroquine
resistance
Sulfadoxine
Quinine
pyrimethamine
Doxycycline
Mefloquine
Artesunate
Artemether
Slide26
WHO Guidelines For Malaria 2006
Treatment of uncomplicated malaria:
Vivax
malaria: (1)
chloroquine
600mg ( 10mg/kg) followed by 300mg ( 5mg/kg) after 8 hours and then for next 2 days.( total dose 25mg/kg over 3 days)+
primaquine
15mg (0.25mg/kg) daily for 14 days.
(2)Quinine 600mg (10mg/kg) 8 hourly for 7
days+doxycycline
100mg daily for 7
days+primaquine
(as above)
Slide27
Chloroquine
sensitive
falciparum
malaria:
(1)
Chloroquine
(as above)+
primaquine
45mg(0.75mg/kg) single dose
(2)
Sulfadoxine
1500mg(25mg/kg)+
pyrimethamine
75mg(1.25mg/kg) single
dose+primaquine
0.75mg/kg single dose
Slide28
Chloroquine
resistant
falciparum
malaria
(1)A75mg single dose
Or
artesunate
100mg BD for 3
days+mefloquine
750mg (15mg/kg) on 2
nd
day and 500mg (10mg/kg) on 3
rd
day
Or
artemether
80mg +
lumefantrine
480mg twice daily for 3 days.
or Quinine 600mg (10mg/kg) 8 hourly for 7 days +
doxycycline
100mg daily for 7 days
rtesunate
100mg BD for 3
days+sulfadoxine
1500mg +
pyrimethamine
Slide29
Treatment of severe and complicated
falciparum
malaria:
(1)
Artemether
2.4mg/kg iv or
iM
followed by 2.4mg/kg after 12 and 24 hours and then once daily for 7 days
Or
artemether
3.2mg/kg
iM
on 1
st
day followed by 1.6mg/kg daily for 7 days
Or quinine loading dose: 20mg/kg and maintain 10mg/kg
