Malaria PDF

HPS-305 Malaria I & II Presented by Dr Sarah Abusham  Learning objectives 1.Describe the etiology and lifecycle of Plasmodium species. 2.Identify the clinical features and complications of malaria. 3.Demonstrate knowledge of diagnostic methods for malaria. 4.Explain the principles of treatment an...

HPS-305 Malaria I & II Presented by Dr Sarah Abusham  Learning objectives 1.Describe the etiology and lifecycle of Plasmodium species. 2.Identify the clinical features and complications of malaria. 3.Demonstrate knowledge of diagnostic methods for malaria. 4.Explain the principles of treatment and management of uncomplicated and severe malaria. 5.Discuss preventive strategies and emerging trends in malaria control www.vision.edu.sa Malaria Malaria is a life-threatening disease caused by Plasmodium parasites, transmitted to humans through the bites of infected female Anopheles mosquitoes. Global Impact: Over 200 million cases annually, with significant mortality, particularly in sub-Saharan Africa. Vulnerable groups include children under five, pregnant women, and immunocompromised individuals. www.vision.edu.sa  Causative Organisms: Plasmodium falciparum – most lethal. Plasmodium vivax –. Plasmodium ovale –. Plasmodium malariae – causes chronic infections. Plasmodium knowlesi www.vision.edu.sa Life Cycle of Plasmodium Human Host (Asexual Cycle): Sporozoites are injected into the bloodstream by an infected mosquito. Sporozoites infect liver cells and multiply (exoerythrocytic stage). Liver cells rupture, releasing merozoites into the bloodstream. Merozoites invade red blood cells (RBCs), leading to trophozoite and schizont development. Infected RBCs rupture, releasing more merozoites, causing cyclical symptoms. www.vision.edu.sa  Mosquito Host (Sexual Cycle): Some merozoites develop into male and female gametocytes. Gametocytes are ingested by a mosquito during a blood meal and completing the cycle www.vision.edu.sa www.vision.edu.sa  Pathophysiology: RBC destruction leads to anemia. (Red cells are destroyed both by the release of the merozoites and by the action of the spleen to first sequester the infected red cells and then to lyse them). Release of inflammatory cytokines contributes to fever and systemic symptoms. www.vision.edu.sa  Malaria caused by P. falciparum is more severe than that caused by other plasmodia. It is characterized by: ❖ infection o more red cells than the other malarial species ❖ and by occlusion of the capillaries with aggregates of parasitized red cells. This leads to life-threatening hemorrhage and necrosis, particularly in the brain (cerebral malaria). www.vision.edu.sa Clinical Features: Incubation Period: 7-30 days, depending on the species. Symptoms: Uncomplicated Malaria: Classical triad: Fever, chills, and sweating. Associated symptoms: Headache, myalgia, nausea, vomiting, and fatigue. www.vision.edu.sa  Severe Malaria (P. falciparum): Cerebral malaria, Severe anemia, Acute respiratory distress syndrome (ARDS), Renal failure, Metabolic acidosis. Complications: Hypoglycemia, Disseminated intravascular coagulation (DIC), shock www.vision.edu.sa Low birth weight www.vision.edu.sa Tropical splenomegaly www.vision.edu.sa www.vision.edu.sa  Diagnosis Clinical suspicion: Travel history to endemic regions. Febrile illness with non-specific symptoms. Laboratory diagnosis: Microscopy: Giemsa-stained blood smears (thick and thin smears). Gold standard in many settings. Rapid diagnostic tests (RDTs): Detect Plasmodium-specific antigens. Molecular methods: PCR www.vision.edu.sa  Complete blood count (CBC): Anemia, thrombocytopenia. Additional investigations: Serum lactate, renal function tests, and glucose levels for complication www.vision.edu.sa THICK (upper slide) &THIN (lower slide) films www.vision.edu.sa www.vision.edu.sa Plasmodium falciparum www.vision.edu.sa www.vision.edu.sa 1st line of treatment (Artesunate plus Sulphadoxine-Pyrimethamine www.vision.edu.sa Complicated malaria Quinine(I.V infusion) Artemether(I.M injection www.vision.edu.sa  Prevention Personal protection Chemoprophylaxis:Recommended for travelers to endemic areas. Vaccination: (Mosquirix): First malaria vaccine approved. Mosquito control. www.vision.edu.sa Prevention Mosquito control. www.vision.edu.sa Thank You www.vision.edu.sa