Malaria Prof Ahmed A Adeel Malaria Species Four

  • Slides: 32
Download presentation
Malaria Prof. Ahmed A Adeel

Malaria Prof. Ahmed A Adeel

Malaria Species • Four species of malaria : – Plasmodium falciparum: malignant tertian malaria

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

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

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

LIFE CYCLE OF MALARIA Oocyst Sporozoites Zygote Stomach Wall Salivary Gland sporozoites Gametocytes Pre-erythrocytic

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

Components of the Malaria Life Cycle Sporogonic cycle Infective Period Mosquito bites uninfected person

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

CLINICAL SIGNS & SYMPTOMS Hot stage Sweating Cold stage

CLINICAL SIGNS & SYMPTOMS Hot stage Sweating Cold stage

Plasmodium falciparum: : Plasmodium vivax, Plasmodium ovale Plasmodium malariae:

Plasmodium falciparum: : Plasmodium vivax, Plasmodium ovale Plasmodium malariae:

CLINICAL PICTURE Acute Disease Non-severe Acute Febrile disease Cerebral Malaria Death Chronic Disease Chronic

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

Uncomplicated malaria • Uncomplicated malaria is defined as: Symptomatic infection with malaria parasitemia without

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

Malarial Paroxysm cold stage • feeling of intense cold • vigorous shivering • lasts

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

Severe malaria • Severe malaria is defined as symptomatic malaria in a patient with

Severe malaria • 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 (glood glucose < 2. 2 mmol/l or 40 mg/dl ) – Metabolic acidosis with respiratory distress (arterial p. H < 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)

Complications of malaria : Cerebral malaria

Complications of malaria : Cerebral malaria

Complications of malaria : Pulmonary oedema

Complications of malaria : Pulmonary oedema

Complications of malaria : anaemia Child with severe malaria anaemia and no other malaria

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

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

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

Malarial haemoglobinuria Clinical Picture : Patients with glucose-6 -phosphate dehydrogenase (G 6 PD) deficiency

Malarial haemoglobinuria Clinical Picture : Patients with glucose-6 -phosphate dehydrogenase (G 6 PD) 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.

Laboratory diagnosis of malaria

Laboratory diagnosis of malaria

Laboratory diagnosis of malaria

Laboratory diagnosis of malaria

Laboratory diagnosis of malaria

Laboratory diagnosis of malaria

Laboratory diagnosis of malaria CCMOVBD Plasmodium falciparum Plasmodium malariae CCMOVBD Malaria Tutorials, Wellcome Trust

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

Laboratory diagnosis of malaria Features of Plasmodium Vacuole Nucleus/chromatin dot Cytoplasm Stippling CCMOVBD

Laboratory diagnosis of malaria Features of Plasmodium Vacuole Nucleus/chromatin dot Cytoplasm Stippling CCMOVBD

Laboratory diagnosis of malaria The Malaria Parasite Trophozoites Three developmental stages seen in blood

Laboratory diagnosis of malaria The Malaria Parasite Trophozoites Three developmental stages seen in blood films: CCMOVBD Schizont Gametocyte 1. Trophozoite 2. Schizont 3. Gametocyte CCMOVBD

Laboratory diagnosis of malaria Plasmodium falciparum (trophozoite stage) Plasmodium facliparum Multiple infection Diagnostic Points:

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

Laboratory diagnosis of malaria Rapid diagnostic tests detect malaria antigens

Laboratory diagnosis of malaria Rapid diagnostic tests detect malaria antigens

Rapid diagnostic tests detect malaria antigens Plastic cassette format of RDT

Rapid diagnostic tests detect malaria antigens Plastic cassette format of RDT

Rapid diagnostic tests detect malaria antigens

Rapid diagnostic tests detect malaria antigens

ACTION OF ANTIMALARIAL DRUG IN THE DIFFERENT LIFE STAGES OF THE MALARIA PARASITE Sporontocides

ACTION OF ANTIMALARIAL DRUG IN THE DIFFERENT LIFE STAGES OF THE MALARIA PARASITE Sporontocides • Primaquine • Pyrimethamine • Proguanil Gametocyide Primaquine Tissue Schizontocides • Primaquine • Pyrimethamine • Tetracycline • Proguanil Anti-relapse (P. vivax) • primaquine Blood Schizontocides • Chloroquine • Sulfadoxine/Pyrimethamine • Quinidine • Artemisinins Wellcome Trust (Modified)

Main Malaria Control Measures 1. Early diagnosis and treatment of cases 2. Vector control

Main Malaria Control Measures 1. Early diagnosis and treatment of cases 2. Vector control : • adult mosquitoes : insecticides • mosquito larvae: draining breeding sites 3. Reducing vector-human contact: bed nets , repellents 4. Early detection and control of epidemics

Malaria Prevention in Travelers: (1) Specific chemoprophylaxis ( http: //www. who. int/ith/en/ ) (2)

Malaria Prevention in Travelers: (1) Specific chemoprophylaxis ( http: //www. who. int/ith/en/ ) (2) Avoiding contact with malaria vectors ( repellents , bed nets) (3) Stand-by treatment , early diagnosis and treatment