2. Malaria An Overview of Life-cycle, Morphology and Clinical Picture

3. Malaria Species Four species of malaria : –Plasmodium falciparum: malignant tertian malaria –Plasmodium vivax: benign tertian malaria –Plasmodium ovale : benign tertian malaria –Plasmodium malariae: quartan malaria

4. Estimated incidence malaria episodes(caused by any species) resulting from local transmission, country level averages, 2004

6. Exo-erythrocytic (hepatic) cycle Hypnozoites Sporozoites Salivary Gland LIFE CYCLE OF MALARIA Gametocytes Erythrocytic Cycle Zygote Oocyst Stomach Wall Pre-erythrocytic (hepatic) cycle sporozoites

7. Components of the Malaria Life Cycle Mosquito Vector Human Host Sporogonic cycle Infective Period Mosquito bites gametocytemic person Mosquito bites uninfected person Prepatent Period Incubation Period Clinical Illness Parasites visible Recovery Symptom onset

8. CLINICAL SIGNS & SYMPTOMS Hot stage Cold stage Sweating

9. Plasmodium falciparum:: Plasmodium vivax, Plasmodium ovale Plasmodium malariae\:

10. Chronic Disease Chronic Asymptomatic Infection Placental Malaria Anemia Infection During Pregnancy Developmental Disorders; Transfusions; Death Low Birth weight Increased Infant Mortality Acute Disease Non-severe Acute Febrile disease Cerebral Malaria Death CLINICAL PICTURE

11. Definition Severe malaria is defined as symptomatic malaria in a patient with P. falciparum asexual parasitaemia with one or more of the following complications: –Cerebral malaria ( unrousable coma not attributable to other causes). –Generalised convulsions ( > 2 episodes within 24 hours) –Severe normocytic anaemia ( Ht<15% or Hb < 5 g/dl) –Hypoglycaemia (g lood glucose < 2.2 mmol/l or 40 mg/dl ) –Metabolic acidosis with respiratory distress (a rterial pH < 7.35 or bicarbonate < 15 mmol/l) –Fluid and electrolyte disturbances –Acute renal failure ( urine <400 ml/24 h in adults; 12 ml/kg/24 h in children) –Acute pulmonary oedema and adult respiratory distress syndrome –Abnormal bleeding –Jaundice –Haemoglobinuria –Circulatory collapse, shock, septicaema (algid malaria) –Hyperparasitaemia (>10% in non-immune; >20% in semi-immune)

12. Definition Uncomplicated malaria is defined as: Symptomatic infection with malaria parasitemia without signs of severity and/or evidence of vital organ dysfunction.

13. Complications of malaria : Cerebral malaria

14. Malarial Paroxysm cold stage feeling of intense cold vigorous shivering lasts 15-60 minutes hot stage intense heat dry burning skin throbbing headache lasts 2-6 hours sweating stage profuse sweating declining temperature exhausted and weak → sleep lasts 2-4 hours

21. Complications of malaria : Pulmonary oedema

22. Child with severe malaria anaemia and no other malaria complication Complications of malaria : anaemia

23. Child with severe malaria anaemia in conjunction with acidosis and respiratory distress

24. Clinical Picture : Patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency may develop intravascular haemolysis and haemoglobinuria precipitated by primaquine and other oxidant drugs, even in the absence of malaria. Haemoglobinuria associated with malaria (“blackwater fever”) is uncommon and malarial haemoglobinuria usually presents in adults as severe disease with anaemia and renal failure. Malarial haemoglobinuria

25. Laboratory diagnosis of malaria

32. CCMOVBD Plasmodium falciparum CCMOVBD Plasmodium vivax CCMOVBD Plasmodium malariae Malaria Tutorials, Wellcome Trust Plasmodium ovale Laboratory diagnosis of malaria

33. Features of Plasmodium CCMOVBD Nucleus/chromatin dot Cytoplasm Stippling Vacuole

34. 3. Gametocyte The Malaria Parasite Three developmental stages seen in blood films: 1.Trophozoite 2. Schizont CCMOVBD Trophozoites CCMOVBD GametocyteSchizont CCMOVBD

35. Plasmodium falciparum (trophozoite stage) Diagnostic Points: Small, regular, fine to fleshy cytoplasm Infected RBCs not enlarged Numerous, multiple infection is common Ring, comma, marginal or accole forms are seen; often have double chromatin dots Maurer’s dots not clearly visible CCMOVBD Multiple infection Double chromatin Marginal form

36. Laboratory diagnosis of malaria Rapid diagnostic tests detect malaria antigens

37. Plastic cassette format of RDT Rapid diagnostic tests detect malaria antigens

39. WHO recommends parasitological diagnosis of malaria with microscopy or, where not available, RDTs, in the following circumstances: 1.to guide malaria case management in areas with low to moderate transmission[1] ;[1] 2.for confirmation of a malaria epidemics; 3.for monitoring changes of malaria prevalence over time; 4.for the assessment of patients with suspected severe malaria; 5.for investigating antimalarial treatment failures. [1][1] In areas of low transmission incidence of malaria is lower than in areas of intense transmission: most infections are symptomatic and all age-groups are equally affected. WHO recommendations on RDT

40. ACTION OF ANTIMALARIAL DRUG IN THE DIFFERENT LIFE STAGES OF THE MALARIA PARASITE Wellcome Trust (Modified) Tissue Schizontocides PrimaquinePrimaquine PyrimethaminePyrimethamine TetracyclineTetracycline ProguanilProguanil Anti-relapse (P.vivax) primaquine Blood Schizontocides Chloroquine Sulfadoxine/Pyrimethamine Quinine Quinidine Artemisinins GametocyidePrimaquine Sporontocides PrimaquinePrimaquine PyrimethaminePyrimethamine ProguanilProguanil