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Malaria

Malaria. Course Objectives. Basic understanding of malaria Epidemiology Symptoms Diagnosis Treatment Prevention. Name means “bad air”- A life-threatening parasitic disease 40% of the world’s population is at risk

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Malaria

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  1. Malaria

  2. Course Objectives • Basic understanding of malaria • Epidemiology • Symptoms • Diagnosis • Treatment • Prevention parasite lab.5 by l. wafa menawi

  3. Name means “bad air”- • A life-threatening parasitic disease • 40% of the world’s population is at risk • 90% of the deaths due to Malaria occur in Sub-Sahara Africa, mostly among young children. • Around 400-900 million people are affected • At least 2.7 million deaths annually. • It is one of the major public health concerns parasite lab.5 by l. wafa menawi

  4. Organism • Malaria is caused by species of Plasmodium. • The genus Plasmodium contains 172 species • only four species are known to infect humans. • Plasmodium falciparum • Plasmodium malariae • Plasmodium ovale • Plasmodium vivax • Plasmodium parasites are highly specific with female Anopheles mosquitoes parasite lab.5 by l. wafa menawi

  5. Transmission • Mosquito vector: ANOPHELES • Transmission also possible through: Blood transfusion Contaminated needle Organ transplant Congenital parasite lab.5 by l. wafa menawi

  6. Incubation Period • P. Malariae • 30 days * May be 8 - 10 months or longer for some strains parasite lab.5 by l. wafa menawi

  7. parasite lab.5 by l. wafa menawi

  8. parasite lab.5 by l. wafa menawi

  9. Transmission • sporozoites injected with saliva • enter circulation • trapped by liver (receptor-ligand) parasite lab.5 by l. wafa menawi

  10. Plasmodium parasite lab.5 by l. wafa menawi

  11. Malaria Transmission Cycle Exo-erythrocytic (hepatic) Cycle: Sporozoites infect liver cells and develop into schizonts, which release merozoites into the blood Sporozoires injected into human host during blood meal Parasites mature in mosquito midgut and migrate to salivary glands HUMAN MOSQUITO Erythrocytic Cycle: Merozoites infect red blood cells to form schizonts Some merozoites differentiate into male or female gametocyctes Parasite undergoes sexual reproduction in the mosquito parasite lab.5 by l. wafa menawi

  12. The malaria parasite life cycle involves two hosts.  • Saprogenic Stage • During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host.  • Hepatic Stage • Sporozoites infect liver cells and mature into schizonts , which rupture and release merozoites into the bloodstream.  parasite lab.5 by l. wafa menawi

  13. Blood Stage • Merozoites infect red blood cells • The parasites undergo asexual multiplication in the erythrocytes. • The ring stage trophozoites mature into schizonts, which rupture releasing merozoites. • Some parasites differentiate into male and female gametocytes.  • Blood stage parasites are responsible for the clinical manifestations of the disease.  parasite lab.5 by l. wafa menawi

  14. The male and female gametocytes are ingested by another Anopheles mosquito.  • The parasites’ multiplication in the mosquito is known as the sporogonic cycle, generating zygotes.  • The zygotes develop into oocysts.  • The oocysts grow, rupture, and release sporozoites, which make their way to the mosquito's salivary glands.  • Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle .  parasite lab.5 by l. wafa menawi

  15. Exo-erythrocytic (tissue) phase • P. vivax and P. ovale hypnozoites remain dormant for months • They develop and undergoe pre-erythrocytic sporogeny • The schizonts rupture, releasing merozoites and producing clinical relapse parasite lab.5 by l. wafa menawi

  16. Erythrocytic phase • Pre-patent period – interval between date of infection and detection of parasites in peripheral blood • Incubation period – time between infection and first appearance of clinical symptoms • Merozoites from liver invade peripheral (RBC) and develop causing changes in the RBC • There is variability in all 3 of these features depending on species of malaria parasite lab.5 by l. wafa menawi

  17. Erythrocytic phasestages of parasite in RBC • Trophozoites are early stages with ring form the youngest • Tropohozoite nucleus and cytoplasm divide forming a schizont • Segmentation of schizont’s nucleus and cytoplasm forms merozoites • Schizogeny complete when schizont ruptures, releasing merozoites into blood stream, causing fever • These are asexual forms parasite lab.5 by l. wafa menawi

  18. Erythrocytic phasestages of parasite in RBC • Merozoites invade other RBCs and schizongeny is repeated • Parasite density increases until host’s immune response slows it down • Merozoites may develop into gametocytes, the sexual forms of the parasite parasite lab.5 by l. wafa menawi

  19. Schizogenic periodicity and fever patterns • Schizogenic periodicity is length of asexual erythrocytic phase • 48 hours in P.f., P.v., and P.o. (tertian) • 72 hours in P.m. (quartian) • Initially may not see characteristic fever pattern if schizogeny not synchronous • With synchrony, periods of fever or febrile paroxsyms assume a more definite 3 (tertian)- or 4 (quartian)- day pattern parasite lab.5 by l. wafa menawi

  20. Acute Symptoms • Classical cyclic paroxysm: • Cold stage: chills and shaking • Hot stage: warm, headache, vomiting • Sweating stage: weakness • Feel well for period of time, then cycle repeats itself parasite lab.5 by l. wafa menawi

  21. Fever 96% • Chills 96% • Headache 79% • Muscle Pain 60% • Palpable liver 33% • Palpable Spleen 28% • Nausea or vomiting 23% • Abdominal pain/diarrhea 6% parasite lab.5 by l. wafa menawi

  22. Complicated Malaria • Hyperparisitemia: (>3%) • Hypoglycemia: (<60 mg/dl) • Severe anemia (hct < 21% or rapidly falling hct) • Renal failure • Hyponatremia • Cerebral malaria • Prolonged hypothermia • High output vomiting or diarrhea • Pregnancy parasite lab.5 by l. wafa menawi

  23. Congenital malaria • Transplacental infection • Can be all 4 species • Commonly P.v. and P.f. in endemic areas • P.m. infections in nonendemic areas due to long persistence of species • Neonate can be diagnosed with parasitemia within 7 days of birth or longer if no other risk factors for malaria (mosquito exposure, blood transfusion) parasite lab.5 by l. wafa menawi

  24. Fever, irritability, feeding problems, anemia, hepatosplenomegaly, and jaundice • Be mindful of this problem even if mother has not been in malarious area for years before delivery parasite lab.5 by l. wafa menawi

  25. Immunity • Influenced by • Genetics • Age • Health condition • Pregnancy status • Intensity of transmission in region • Length of exposure • Maintenance of exposure parasite lab.5 by l. wafa menawi

  26. Immunity • Innate • Red cell polymorphisms associated with some protection • Hemoglobin S sickle cell trait or disease • Hemoglobin C and hemoglobin E • Thalessemia – α and β • Glucose – 6 – phosphate dehydrogenase deficiency (G6PD) • Red cell membrane changes • Absence of certain Duffy coat antigens improves resistance to P.v. parasite lab.5 by l. wafa menawi

  27. DIAGNOSIS • Gold standard: Multiple thick and thin smears • Dip stick tests • CBC • Anemia • Leukopenia, or leukocytosis • No eosinophilia parasite lab.5 by l. wafa menawi

  28. parasite lab.5 by l. wafa menawi

  29. parasite lab.5 by l. wafa menawi

  30. Erythrocytic Schizogony parasite lab.5 by l. wafa menawi

  31. Treatment • CHLOROQUINE sensitive infections: • CHLOROQUINE 600 mg (2 tabs) initially • 300 mg (1 tab) in 6 hrs • 300 mg (1 tab) for 2 days parasite lab.5 by l. wafa menawi

  32. Uncomplicated CHLOROQUINE-resistant infections: • Quinine 650 mg x 3 days and DOXYCYCLINE 100 mg x 7 days, • OR • MEFLOQUINE 1000-1500 mg once • Complicated or severeinfections • I.V. QUINIDINE or quinine parasite lab.5 by l. wafa menawi

  33. Optimal Treatment Approach • Rapid case identification • Rapid PARASITOLOGICAL classification • Rapid initiation of therapy • Rapid initiation of supportive care parasite lab.5 by l. wafa menawi

  34. Control Of Malaria • Global eradication efforts by WHO in 1950s • Efforts now focus on CONTROL vs ERADICATION parasite lab.5 by l. wafa menawi

  35. Points Of Attack 1. Attack the parasite in the human host 2. Reduce contact between humans and mosquitoes 3. Decrease mosquito population parasite lab.5 by l. wafa menawi

  36. Attack The Parasite In The Human Host • Treat malaria infections with effective medications • Use prophylactic drugs to prevent illness and/or infection parasite lab.5 by l. wafa menawi

  37. Reduce Contact Between Humans And Mosquitoes • Personal protective measures • Proper wearing of uniform • DEET • PERMETHRIN • Bed nets parasite lab.5 by l. wafa menawi

  38. Decrease Mosquito Population • Surveillance of mosquito populations • Identify and eliminate breeding sites • Proper insecticide application • Attack larval stages • Attack adult mosquito parasite lab.5 by l. wafa menawi

  39. Malaria! • Remember: Flu-like Symptoms + ‘Recent’ Hx Travel To Malarious Area = Think Malaria parasite lab.5 by l. wafa menawi

  40. allah protect you, and an nature will help you when you .............. parasite lab.5 by l. wafa menawi

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