Malaria

plasmodium is a very important topic for pg entrance........so every important point about it have been discussed in detail......take a look at it...

1. MALARIA -DR.AKIF A.B

2. When Transmitted by blood transfusion There is no liver stage since parasite directly enters blood Hypnozoites are not found Hence there is no relapse No need for Primaquine

3. INFECTIVE FORMS Infective form to man = Sporozoites present in salivary glands of Mosquito 2) Infective form to man in case of blood transfusion 3) Infective form to mosquito = Gametocytes - To infect mosquito, Gametocyte must be mature, viable, count >12per cubic mm. merozoites

4. P.Vivax P.Falciparum P.Malariae P.Ovale Relapse( Hypnozoites ) seen Not seen Not seen Seen Recrudescenece Not seen seen seen Not seen Incubation period 14days 12days 28days 17days Erythrocytic cycle 48hrs 48hrs 72hrs 48hrs

5. RECRUDESCENCE RELAPSE Recrudescence is due to persistence of drug resistant parasite. In Falciparum : Disease appears after 2-3weeks of completion of treatment In Malariae ; Disease appears very late almost after 60yrs. -due to hypnozoites May reappear after2-3yrs Seen in P.vivax and ovale .

6. Species Disease Periodicity P.Vivax Benign tertian 48hrs P.Falciparum Malignant tertian 48hrs P.Ovale Ovale tertian 48hrs P.Malariae Quartian 72hrs P.Knowlesi Quotidian 24hrs

7. Larvae

8. NATURE OF RBCs Plasmodium spcies Type of RBC P.Vivax Young RBCs P.Falciparum RBCs of all age P.Ovale Reticulocytes /Young RBCs P.Malariae Old RBCs

9. PROTECTIVE FROM MALARIA Sickle cell trait Protective from P.falciparum Thallasemia trait Protective from P.falciparum Fetal Hb Protective from P.falciparum G6PD deficiency Protective from P.falciparum Ovalocytosis Protective from P.falciparum Duffy negative RBCs Protective from P.vivax

10. Plasmodium knowlesi It is a parasite of monkey but can also affect humans Early trophozoite resembles to P.falciparum Late trophozoite resembles to P.malariae Quotidian malariae

11. P.Vivax P.Falciparum P.Malariae P.ovale Forms seen in peripheral blood smear Early and late trophozoites , gametocytes and schizonts Ring forms (early trophozoites ) and gametocytes Similar to that of vivax Ring forms are known as Band forms. Similar to that of vivax Gametocye Spherical, almost occupies RBC Banana shape, larger than RBC Similar to that of vivax Similar to that of vivax RBC size Enlarged Normal Normal enlarged Stippling Schuffner’s dots ( small red dots) Maurer’s cleft ( large red spots) Ziemann’s dots James dots

12. Maurer’s Cleft

13. P.falciparum Gameto cytes

14. Blood Smear Examination Thin smear = for species identification Thick smear = for quantification

15. ANTIGEN DETECTION TESTS pLDH and Aldolase = common to all plasmodium species HRP-2 Ag detection = specific for P.falciparum

16. BABESIA Not found in INDIA Vector : Tick borne Zoonotic Diagnostic form: Maltese cross : Ring forms are arranged in Tetrads

17. BABESIA

18. PRACTICE QUESTIONS

19. Man is intermediate host for: (DNB June 2011) A Brugia malayi B W. Bancrofti C Plasmodium D Echinococcus

20. Ans. C & D Humans act as intermediate host for Plasmodium, Toxoplasma , Babesia and Echinococcus , T . Solium . Intermediate host for W. Bancrofti and Brugia malayi is mosquito

21. 2) In malaria, infective stage injected into human subjects by the mosquito is: A Sporozoite B Merozoite C Cryptozoite D Gametocyte

22. Ans. A Sporozoite Man : intermediate host Female anopheles mosquito: definitive host b. In malaria infective stage for humans is sporozoites . c. Human cycle ( Schizogony / asexual cycle ): female anopheline mosquito bites→ sporozoites injected→ general circulation→ invade hepatocytes → preerythrocytic schizogony → merozoites → invade rbcs → erythrocytic schizogony → some merozoites develop into gametocytes d. Mosquito cycle ( Sporogony / sexual cycle): female anopheline mosquito bites→ picks macrogametocyte & microgametocyte→ exflagellation of microgametocyte→ penetrates one macrogamete→ zygote→ ookinete → penetrates the epithelial lining & muscular wall & lies below the outer limiting membrane of the stomach→ oocyst → sporocyst containing sporozoites → rupture, sporozoites liberated in the body cavity→ reach salivary gland

23. 3. Duration of pre- erythrocytic schizogony in Plasmodium falciparum is : (AIIMS Nov 2011) A 2 days B 5 days C 9 days D 13 days

24. Ans. B 5 days Duration of Pre- erythrocytic ( exo-erythrocytic ) schizogony : P . Falciparum-5.5 days, P . Vivax-8 days, P . Ovale - 9 days, P . Malariae - 15days.

25. 4. What is the site of pre- erythrocytic cycle of malaria? A Anopheles B Paranchymal cells of liver C Kupfer cells of liver D Spleen

26. Ans. B Parenchymal cells of liver. Pre- erythrocytic stage occurs in the hepatocytes

27. 5. Blackwater fever results from: (DNB Dec 2011) A Intravascular haemolysis B Nephrotic syndrome C Alkaptonuria D Paroxysmal nocturnal hemoglobinuria

28. Ans. A Intravascular haemolysis a. Black water fever is because of intravascular hemolysis . b. It is caused by rapid and massive destruction of red blood cells with the production of hemoglobinemia , hemoglobinuria , intense jaundice, anuria , and finally death c. In the majority of cases. The most probable explanation for blackwater fever is an autoimmune reaction apparently caused by the interaction of the malaria and quinine

29. 6. In falciparum malaria, all the following states are seen except:. A Ring stage B Gametocyte C Schizont D Sporozoite

30. Ans. C Schizont a . Erythrocytic schizogony occurs in the capillaries of internal organs and only the early ring forms and the gametocytes are seen in the peripheral smear . b. Late trophozoite and schizont are not seen in peripheral blood in falciparum malaria.

31. 7. Banana shaped gametocytes in peripheral smear are seen in infection with: (AIIMS May 2011) A Plasmodium vivax B Plasmodium malaria C Plasmodium falciparum D Plasmodium ovale

32. Ans. C Plasmodium falciparum Banana shaped or crescent shaped gametocytes are seen in P. Falciparum .

33. 8. All are seen in Plasmodium falciparum infection except: A Hemoglobinuria B Cerebral malaria C Relapses D Malignant malaria

34. Ans. C Relapses Relapses are due to hypnozoites in liver. These are seen in case of P.vivax and P.ovale . P. Falciparum is not associated with relapses.

35. 9. Microscopic examination of a thin blood smear from a patient suspected of having malaria reveals numerous normal size erythrocytes without stippling but with ring stages, many with multiple ring stages and applique forms. Several erythrocytes show developing trophozoites that are spread across the erythrocytes in a band fashion. Which of the following is the most likely cause of infection? (AIPG 2011) A Plasmodium vivax B Plasmodium malariae C Plasmodium falciparum D A mixed infection with two plasmodium species

36. Ans. D A mixed infection with two plasmodium species Multiple ring stages and applique forms are indicative of P. Falciparum ; several erythrocytes show developing trophozoites that are spread across the erythrocytes in a band fashion that is indicative of P. Malariae infection . b. Normal size erythrocytes without stippling ( Schuffner dots) would exclude P. Vivax and P. Ovale .

37. 10. A patient in the city of Pune was diagnosed with malaria acquired through a blood transfusion. A discussion of this case by physicians included the following statements. Which statement is correct? A The infected blood contained sporozoites . B The patient should be treated with chloroquine and primaquine . C The patient should be treated to eradicate the stages responsible for symptoms . D The blood donor had chloroquine -resistant malaria.

38. Ans. C The patient should be treated to eradicate the stages responsible for symptoms . a. The primary goal should be to treat the patient to eliminate the erythrocytic cycle that is the cause of symptoms . b. This would constitute a radical cure because the liver phase only occurs if infection is initiated by sporozoites . Thus, treating with primaquine (B) is not necessary because the patient will not harbor hypnozoites . c. Likewise, (A) is not correct because sporozoites are only acquired from mosquitoes. Transfusion malaria is caused by schizonts and merozoites present in the transferred blood . d. There is no way to know that the malaria is chloroquine resistant until after treatment with chloroquine (D)

39. 11. Cerebral malaria most commonly attends infection with which of the following? A Plasmodium vivax B Plasmodium malariae C Plasmodium falciparum D Plasmodium ovale

40. Ans. C Plasmodium falciparum Cerebral malaria involves the clinical manifestations of Plasmodium falciparum malaria that induce changes in mental status and coma and is accompanied by fever . b. Without treatment, cerebral malaria is fatal in 24-72 hours and the mortality ratio is between 25-50 percent . c. The common histopathological finding is the sequestration of parasitized and nonparasitized red blood cells in cerebral capillaries and venules .

41. 12. A 29-year-old man feels tired and has sore muscles, so he consults a physician, who examines him, but decides not to admit him to the hospital. The man subsequently develops a disabling illness complicated by severe anemia, pulmonary edema, renal failure, and shock. Which of the following organisms is the most likely pathogen? (AIPG 2012) A Babesia microti B Plasmodium falciparum C Plasmodium malariae D Plasmodium ovale

42. Ans. B Plasmodium falciparum a.This is the history of complicated P. Falciparum infection . b. The complications associated with P. Falciparum include: pernicious malaria, black water fever, algid malaria, cerebral malaria, pulmonary edema, ARDS and metabolic acidosis.

43. 13. Which of the following species of Plasmodium has special affinity for reticulocytes : (AIIMS Nov 2012) A P ovale B P vivax C P malariae D P falciparum

44. Ans. A P ovale P. Falciparum infects RBC’s of all ages P. Vivax infects RBC’s < 14 d P. Malariae infects old RBC’s P. Ovale selectively infect reticulocytes

45. 14. All of the following are complication of Plasmodium falciparum infection except A Blackwater fever B Cerebral malaria C Recrudescent malaria D Nephropathy

46. Ans. D Nephropathy a . Nephropathy is seen in Plasmodium malariae . b. Recrudescence result from persistent erythrocytic infection, which re-emerges within a defined period -usually taken as 28 days following antimalarial treatment in endemic areas . c. Relapse occurs due to reactivation of hypnozoites in the liver . d. Blackwater fever results due to severe intravascular hemolysis . e. Cerebral malaria occurs due to sequestration, rosetting and cytoadherence in cerebral capillaries.

47. 15. Which species of malaria causes nephrotic syndrome A Plasmodium ovale B Plasmodium falciparum C Plasmodium vivax D Plasmodium malariae

48. D Plasmodium malariae

49. 16. Which one of the following is detected by the antigen detection test for the diagnosis of P. Falciparum malaria (AIIMS Nov 2012) A CSP B MSA C HRP1 D HRP2

50. Ans. D HRP2 Malaria rapid diagnostic tests detect the presence of malarial antigens in the blood of the patient. Malarial HRP-II, LDH and aldolase are detected. These are immune-chromatographic tests.

51. 17. Infection with Babesia is most commonly observed in which of the following? A AIDS patient B Foresters C Patients without a spleen D Transfusion recipients

52. Ans. C Patients without a spleen Babesia is a tick-borne organism transmitted by I. Scaputaris , the same tick that transmits Lyrne disease . b. Babesia is often mistaken for Plasmodia (causative organism of malaria) on a blood smear. Patients become anemic and develop hepatosplenomegaly , but patients who are asplenic are at a much greater risk . c. Transfusion recipients, foresters, and immunosuppressed patients may be at risk of acquiring disease but not to the same extent as those patients who have been splenectomized .

53. 18. Maltese cross is associated with (DNB June 2012) A Candida albicans B Penicillium marneffii C Babesia microti D Cryptococcus

54. Ans. C Babesia microti Tetrad forms in RBC’s which represent budding merozoites are called Maltese cross.