Malaria

This presentation is only for educational purpose...:)

2. Malaria
• Agent
–Plasmodium falciparum
– P. vivax
–P. ovale
–P. malariae
•Transmission-by the bite of female anopheles
mosquitoes
•Occurs throughout the tropics and subtropics at
altitudes below 1500 meters

3. Distributions of malaria

4. Distribution of falciparum

5. Drug resistant Malaria
Red - chloroquine resistant
Green - chloroquine sensitive
Black - chloroquine and mefloquine
resistant

8. 3 million deaths/yr. 1 million in Africa,
mostly children below the age of 5

9. Pathology
•Hemolysis of infected red cells and adherence of infected cell to
capillary wall
•Hemolytic anaemia
•dyserythropoiesis,
•splenomegaly
•depletion of folate stores
•P. vivax and P. ovale invade reticulocytes
•P. malariae normoblastsmost
•P. falciparum
•invades red cells of all ages but especially young cells
•red cells containing schizonts adhere to capillary endothelium in
brain, kidney, liver, lungs and gut
•Malaria immune population
•haemoglobin F, C or especially S –falciparum
•lack the Duffy blood group – ovale

10. Pathology

11. Pathology

12. Electronmicroscope view of gut
of mosquito

13. Life cycle of malaria parasite
•Female anopheles feed on human blood containing gametocytes
(Sexual form)
•Complete sexual cycle in mosquito in 7-10 days and become
sporozoites
•Sporozoites inoculated by bite of infected mosquito
•Sporozoites leave the blood stream and enter into the hepatocyte
within half and hour
•Hepatocytes brust after few days and release merozoites
•Merozoites enter into RBCs and multiplication to complete the
asexual life cycle
•Merozoites develop into schizont in RBC and release more
merozoites in the blood and peak fever coincide to this time
•Ovale and vivex may persist in liver cells as dermant forms called
hypnozoites and capable of producing merozoites months or years
later

14. Incubation period and fever
P. vivax/ P. ovale 8-25 days / Tertian
P. malariae 15-30 days / Quartan
P. falciparum 8-25 days / Aperiodic

15. Clinical features
•P. vivax and P. ovale
•Fever with a rigor
•Feeling of cold
•Development of high fever
•Hot or flush phage
•Profuse sweating and gradual fall in fever
•Cycle is repeated 48 hours later
•Spleen and liver enlarge
•Anaemia
•Frequent Relapses in the 1
st
2 years

16. Clinical features
P. malariae
Mild symptoms
Bouts of fever every third day.
Parasitaemia may persist for many years with
recrudescence of fever, or without producing any
symptoms
Causes glomerulonephritis and the nephrotic syndrome
in children

17. P. FALCIPARUM
•Most dangerous of the malarias
•Onset -insidious, with malaise, headache and
vomiting, and is often mistaken for influenza.
•Cough and mild diarrhoea are also common.
•The fever has no particular pattern.
•Jaundice is common due to haemolysis and hepatic
dysfunction.
•The liver and spleen enlarge and become tender.
•Anaemia develops rapidly.
•Develop dangerous complications

18. P Falciparum

19. Complications of falciparum
malaria
Unarousable coma/ convulsion /cerebral malaria
Acidemia/acidosis -Arterial pH <7.25 or plasma
bicarbonate level of <15 mmol/L
Severe normochromic, normocytic anemia
Renal failure -Urine output (24 h) of <400 mL in
adults or <12 mL/kg in children

20. Complications of falciparum
malaria
Pulmonary edema
Noncardiogenic pulmonary edema/adult
respiratory distress syndrome
Hypoglycemia
Hypotension/shock
Bleeding/disseminated intravascular coagulation
Hemoglobinuria
/
Macroscopic black, brown, or
red urine

21. Cerebral malaria
•Severe form of malaria
•Coma is a characteristic and ominous feature
•Despite treatment, is associated with death rates of
~20% among adults and 15% among children.
•Diffuse symmetric manifestation of encephalopathy
•Focal neurology unusal

22. Cerebral malaria
•No signs of meningeal irritation but resistant to passive
neck flexion
•Tonic clonic convulsions
•Deep coma
•Patient recovering may develop sequale( <3% in adult and
about 15% in child)
•Hemiplesia
•Cerebral palsy
•Cortical blindness
•Deafness
•Cognitive and learning defect

23. Features indicating poor prognosis
in falciparum malaria
Clinical Parameter
Marked agitation
 Hyperventilation (respiratory distress)
Hypothermia (<36.5°C)
Bleeding
Deep coma
Repeated convulsions
Anuria
Shock

24. Laboratory parameter
Biochemistry
Hypoglycemia (<2.2 mmol/L)
Hyperlactatemia (>5 mmol/L)
Acidosis (arterial pH <7.3, HCO
3
<15 mmol/L)
Elevated serum creatinine (>265 mol/L)
Elevated total bilirubin (>50 mol/L)
Elevated liver enzymes (AST/ALT X 3 times )
Elevated muscle enzymes (CPK , myoglobin )
Elevated urate (>600 mol/L)

25. Laboratory parameter
 Hematology
Leukocytosis (>12,000/L)
Severe anemia (PCV <15%)
Coagulopathy
Decreased platelet count (<50,000/L)
Prolonged prothrombin time (>3 s)
Prolonged partial thromboplastin time
Decreased fibrinogen (<200 mg/dL)

26. Diagnosis of Malaria

27. Diagnosis
•Thick blood film
•Low parasitemia- thick film erythrocytes are lysed,
releasing all blood stages of the parasite
•Thin film
•confirm the diagnosis,
•to identify the species of parasite
•P. falciparum, only ring forms
•Immunochromatographic 'dipstick' tests or
plasmodium LDH test

28. Management
•P. vivax, P. ovale and P. malariae
•Chloroquine: 600 mg chloroquine base followed by 300
mg base in 6 hours, then 150 mg base 12-hourly for 2
more days
•Mild falciparum malaria
•Quinine dihydrochloride or sulphate drug of choice
-600 mg salt (10 mg/kg) 8-hourly by mouth is given
until the patient is clinically better ,followed by a single
dose of sulfadoxine 1.5 g combined with pyrimethamine
75 mg, i.e. 3 tablets of Fansidar

29. Management of mild falciparum
•Sulphonamide sensitivity
•quinine may be followed by doxycycline 100 mg daily for 7 days
•Atovaquone 250 mg plus proguanil 100 mg (Malarone)
•4 tablets once daily for 3 days
• Artemether plus Mefloquine
•Artemether 200 mg/day orally for 5 days then mefloquine 500 mg in 2
doses 2 hours apart
•Pregnancy a 7-day course of quinine alone

30. Management of severe malaria
•Early and appropriate antimalarial drugs
•Active treatment of complications
•Correction of fluid, electrolyte
•Acid-base balance
•Avoid hypoglycemia
• Avoidance of harmful ancillary treatments

31. Radical cure of malaria
•P. vivax and P. ovale
•Primaquine (15 mg daily for 14 days)
•Destroys the hypnozoite phase in the liver
•S/E-
•Haemolysis (G6PD)-deficient
• Cyanosis due to the formation of methaemoglobin

32. Chemoprophylaxis of malaria
•Chloroquine resistance high
• Mefloquine

250 mg once weekly
• Doxycycline 100 mg daily
• Malarone 100 mg daily
•1 tablet from 1-2 days before travelling to 1 week after return
•Chloroquine resistance moderate
•Chloroquine plus Proguanil 150 mg base+100 mg (Two tablets
weekly+Two tablets daily )
•Chloroquine resistance absent
•Chloroquine or Proguanil 150 mg base or 100 mg (Two
tablets weekly/One or two tablets daily)

33. Malaria control in endemic areas
•Sanitation and improvement in living condition
•Avoid mosquito bites
•Permethrin-impregnated bed nets
•DDT and insecticide spray
•Malaria vaccine under evaluation, in Thailand and
Africa

34. Prevention

35. Prevention

36. Personal protection against
malaria
•Avoidance of exposure to mosquitoes at their peak
feeding times (usually dusk and dawn) and
throughout the night
•Insect repellents creams
•Suitable clothing – full sleeve
•Widespread use of insecticide-impregnated bed nets
or other materials