1) The document provides an overview of malaria including epidemiology, etiology, pathogenesis, clinical manifestations, diagnosis, treatment and prevention. 2) Malaria remains a major global health problem, transmitted by the bite of infected Anopheles mosquitoes. Plasmodium falciparum causes the largest disease burden. 3) Clinical presentation varies depending on malaria species, immunity, and transmission intensity. Uncomplicated malaria typically involves fever, while severe malaria can involve organ dysfunction. Diagnosis involves microscopy or rapid tests to detect the parasite. Treatment depends on malaria species and disease severity.

1. AU, ASOHH, Dep’t OF INT. MEDICINE Yr-III ( C- I ) MEDICAL
STUDENTS ‘ LECTURE ON MALARIA
04 JUL 2011 GC , 8-9AM
NUWAMA BIFA , MD
TOPIC ---- MALARIA
OBJECTIVE - at the end of this session students will be able to
=Mention epidemiology of malaria
= Describe the pathogenesis of malaria.
= Identify the clinical scenarios of malaria.

2. CONTENT-
 introduction 1’
 Epidemiology 5’
 Etiology and pathogenesis 10’
 Clinical manifestation 30’
 Diagnosis 5’
 Treatment outline 3’
 Prevention 5’

3. INTRODUCTION
 Malaria is a protozoal disease transmitted by the bite of
infected Anophles mosquito and the most important
parasitic diseases of humans, with transmission in >107
countries ( >3billion pop) and causing 1-3million
deaths/yr , 150-300deaths/hr.

4. Introd …..
 Has now been eliminated from USA, Canada
,Europe & Russia ,But remain heavy burden on
tropical communities and danger to traveler.
 Critical approach to reduce malarial morbidity
and mortality burden are : more sensitive
diagnostic tools, prompt treatment ,and improved
personal protection and vector control .

5.  EPIDEMIOLOGY
 Malaria occurs throughout tropical regions of the world ,
with p.falciparum causing largest burden, followed by
p.vivax and p.malariae sub-sahara and p.ovale west Africa
However, epidemiology of malaria is complex and vary
considerably within small geographic areas.

6. Epidemio …
Endemicity : defined by parasitemia rates or palpable
spleen rates in children of 2-9yrs
• Hypo endemic <10% X - low transmission, erratic/
focal, Protective immunity is not developed, all ages are
symptomatic. Called unstable transmission.
 Mesoendemic 11-50%
 Hyper endemic 51-74%
 Holoendemic _>75%

7. Epid ….
 Both hyper- and holoendemic are X ‘ed
constant,frequant year round infection ,called
stable transmission. People sustain >1 infectious
mosquito bite/day and are infected repeatedly
throughout theire lives. Adults are asymptomatic(
immunity developed) ,morbidity and mortality thus
considered in children and pregnants.

8. Entomologic inoculation rate( EIR) :
number of infectious mosquito bite/person/yr.
Has seasonal / geographic difference.
 EIR <10/yr ---- low transmission
 EIR 10-49/yr---intermediate
 EIR _ >50/yr—high transmission area/stable transmission

9. Epid …
Principal determinants of malaria epidemiology:
 Vector density (No of vectors) –X of Anophles
Gambiae found in high density, readily breed.
 Human-biting-habit (in/outdoor) ---square of No human
bites/day/mosq.
 Logivity of vector (half life ) ----note; sporogony takes 8-30
days.

10. ETIOLOGY
 Parasites ---Greece word, mean in close association with
another organism of different species ,host
Protozoa : eukaryotic, unicellular
(Plasmodium,leishmania ,toxoplasm,E.histolyt,
Giardia,isospora,cryptosporidiu,T.vaginalis )
Helminths ( helmins-worm ) : metazoa.
Cestoda(tapeworm) e.g taenia sp. ,echinococcus
Trematoda(flukes) e.g schistosoma (blood flukes)

11. Nematoda( roundworm ) ; intestinal and tissue
Arthropods : ectoparasite ; temporary/permanent
Arachnida ; ticks and mite
Insecta ; lice,bugs,fleas ,mosquito and flies
Mosquito---Anophles,culex,Aedes,simulum,phlebotomy ,
Anophles >400 sp. Out of which A.gambiae plasmodium
 PLASMODIUM ; 4 SP. :P.falciparum ,p.vivax ,p.ovale
,p.malariae
-all are humans infective,transmitted by infected anophles ,
Same pathogenesis.

12. MODE OF TRANSMISSION OF MALARIA
1,bite of plasmodium vector,Anophles gambiae (almostall case)
Mosquito meal,ingest gametocyteszygote(in the midgut)
ookinete
penetrate gut wall
hemolymphsalivary glandsporozoite
(motile) through saliva inoculated into noninfectious ind’l upon
next bite.
Takes 8-30days to complete the sexual stage in mosquito.
Note; human stage is asexual.

13. Transm …
 2,blood transfusion ,by needle-stick injury(drug
abusers),organ transplant_ ,congenital .
Noincubation period in these modeof transmission
and rare in occurance

14.  PATHOGENESIS OF MALARIA
Inoculation of sporozoite(anophles bite)Liver (within 15-
45’)few sporozoite is infective,10p.f, hepatocytes
invaded,asexual reproduction begin( tissue schizogony);single
sporozoite gives 10000-30000merozoites tissue schizont
ruptures(6-16days later) merozoites release into blood

15. Pathog…
 RBCs invaded,merozoite attaches to receptor
molecule on RBCs and species-specific (erythrocytic
stage ; ring ,trophozoite ,mature trophoz(pigmented)
schizont ,merozoite) , asexual multiplication
(erythrocytic schizogony) rupture(q48-72hrs)
merozoites released and re-invade another RBCs.  

17.  RBCs change : - intracellular protien(Hgb) degraded,
Cell membrane altered ; transport property ,
Irregular shape , flexiblity lost,become antigenic
Particularly, p. falciparum:
form ‘knobs’ =antigenic-variant ,which
Helps as adhensive.

18. Pathog…
+Cytoadherence----on venules and capillaries
endothelium.
+Rosetting------pf parasitized RBCS adherence on
uninfected RBCs
+Agglutination----on another parasitized RBCs

19. Pathog…
 NOTE; cytoadherence,rosetting,and agglutination are
hallmerk of falciparum malaria pathogenesis ,result in
sequestration parasitizedRBCs into microcirculation
,vital organs particularly brain ,placeta and result in
severe diseases.

20.  HOST RESPONSE ;
 Nonspecific defense involved(Abs-to
sporozoite, merozoite,malaria toxin,fertilization,Cell-
mediated immunity to erytrocytic parasite … )
Splenic immunity -sequestration and clearance.
Genetic protection-e.g Hgb and RBCs-Ag
Hgb ; sickle cell (HgbS),HgbC,HgbF,B-thalassemia
RBCs-Ag ; duffy chemokine receptor
G6PD

21. CLINICAL MANIFESTATION OF MALARIA
 -begin at erythrocytic stage
 -vary with geography,epidemo ,immunity,age and p.species.
 -incubation period ( t inoculation – clinical m.)-
vary among p.sp
p.f =6-16days ,p.v and p.ov =10-21days ,p.m=21-42d
months,even yrs

22. CM …
 clinical form :
*non-falciparum /benign malaria
*uncomplicated falciparum malaria
*severe complicated malaria
*chronic complication of malaria

23.  Clinical manifest. Con’d
 presentation :non-falcip & uncomplicated falcip malaria
-early symptoms ---nonspecific;headache,vomiting,abd pain,diarrh
-classic --- paroxysms 0f fever spike,chills and rigors at regular
p.v / p.ov --------- tertian fever(q48hrs)
p.f ------------------malignant tertian fever
p.m ---------------quartan fever(q72hrs)

24. CM…
 :severe complicated falciparum malaria
Def: acute life-threating malaria with hyperparasitemia
>5-10%parasRBCs / _>100,000 parasites/ microlit
and any SSx of organ dysfunction.
-young children,elderly,non-immune travelers,pregnant,
malnuri . ,RVI ,splenectomy are at high risk.
-paras virulence,host immunity,and t b/n onset and Rx
are important factors.

25. CM…..con’d
Clinical criteria for severity
 cerebral malaria –coma 30’ without any other c
 hypoglycemia
 acidosis
Acute renal failure

26. Criteria for severity…
 Pulmonary edema/ARDS
 Severe anemia;NCNC ,thrombocytopenia,DIC
,(Thrombosis and bleeing)
 Liver injury
 Falciparum malaria in pregnancy

27. Chronic complication of malaria
 Hyperreactive malarial splenomegaly ; response to
chronic/repeated infection
 Anemia , NCNC
Presented with dragging LUQ abd pain& SSx of anemia

28. DIAGNOSIS OF MALARIA
 -clinical ,but no pathognomonic SSx of malaria
 -Light microscope : gold standard ,(Giemsa/Wright’s stain)
;determine sp. ,parasitic density ,& helps to monitor therapy.
 -Rapid diagnostic test (RDT) : immunotochromatography
containing Ab-specific to different epitopes & detect parasitic
Ag proven by microscope.

29. Dx…
 thin BF :
 thick BF :
 -other lab. Test : Hgb, periph
morphology,RBS,RFT,LFT,Serum e ,LP & CSF analysis(
if indicated).

31. TREATMENT OUTLINE OF MALRIA :
1, Non-falciparum malaria,
 A, chloroquine(10mg/kg po ,then 5mg/kg at 12,24,36,hrs)
followed by primaquine(0.25mg/kg po/d/14d) – in CQ
sensitive regions.
 B, artemisinin-based combination therapy(ACT) ,in CQ
resistant regions.

32. Rx-con’d
Uncomplicated falcip malaria,
A, first line ,ACT for 3 days
1, artemether-lumefantrine(coartem20/120)
2, artesunate-amodiaquine(100/270)
3, artesunate-mefloquine(50/250)
4, atresunate-sufadoxina/pyrimethamine(50-500/25)
5, dihydroartemisinin-piperaquine

33. Uncomp falc mal Rx…
B, second line ,for 7days
1, atresunate + TTC or Doxycy. Or Clindamy
2, Quinine + TTC or Doxycy. Or Clindamy
 Pregnant- quinine + Clindamy/7d
 Lactating –all except primaqu,TTC&Doxycy.

34. Rx-con’d
 -severe complicated malaria :
1,Quinine Iv ; loading 20mg/kg/4hrs in 5%DNS,then 12hrs
later maintenance 10mg/kg/4hrs TID until pt can take orally
 full course of ACT .
2,Artesunate Iv /IM ; 2.4mg/kg loading, 1.2mg/kg at 12,24hrs
then daily until pt take po.

35. Rx-con’d
3- if no option ,quininedihydrochloride IM or artemether IM
can be used.
4-supportive treatment ; Rx hypoglycemia, anaemia, fever,
coma care, …
 Chronic malaria :
Chloquine for long duration , 6mos
Splenectomy

36. PERVENTION ;
Def ; control , elimination ,eradication,
 CONTROL :reduction of disease incidence and prevalence to
levels that do not pose a threat to public , MDG 75% / 2015.
Appropriate Rx, personal protection,vector control & vaccine
 ELIMINATION :reduction of incidence and transmission to
zero in humans in a defined geographic area.
 ERADITION : global elimination of human disease .

37. Preven…
CHALLENGES :
-Increase resistance of malarial parasites to chemotherapy
-Increasing resistance of the Anopheles to insecticides
-Ecologic and climate changes
-Increase in international travel to malaria-endemic areas by
non-immune travelers


38. THE END !
THANK YOU !

39. REFERENCES :
 Harrison’s principles of internal medicine ,17th editon,2008
 World health organization guidelines for the treatment of
malaria,2nd edition ,2010
 UpToDate17.3
 Microbiology-ColouAtlas-2005.