CSI153 Clinical Parasitology PDF

CSI153 Clinical Parasitology List and Description of Life cycle, Mode of infection, Disease, Infective Stage and Important Identifying features of Diagnostic Stage. Protozoa: Blood sporozoa (Plasmodium spp.) Ts. Dr. Nurhidayah bint...

CSI153 Clinical Parasitology List and Description of Life cycle, Mode of infection, Disease, Infective Stage and Important Identifying features of Diagnostic Stage. Protozoa: Blood sporozoa (Plasmodium spp.) Ts. Dr. Nurhidayah binti Ab. Rahim Malaria Diploma Teknologi Makmal Perubatan, UiTM (Pulau Pinang), Kampus Bertam At the end of lesson, student should be able to explain about: DISTRIBUTION ROUTE OF TRANSMISSION MORPHOLOGY LIFE CYCLE PATHOGENESIS LAB DIAGNOSIS TREATMENT AND PREVENTION  Malaria parasite (Plasmodium) Pathogen of malaria P. vivax ; P. falciparum ;P. malariae ; P. ovale ; P. knowlesi P. vivax ; P. falciparum are more common Plasmodium is a wide distribution in many tropical or subtropical regions of the world  DISTRIBUTION Transmission will not occur: At very high altitudes During colder seasons in some areas (P. vivax - more tolerant of lower ambient temperatures) In deserts (excluding the oases) In some countries with successful control/elimination programs (Western Europe and US). In warmer regions closer to the equator: Transmission will be more intense Malaria is transmitted year-round. The highest transmission is found in Africa South of the Sahara and in parts of Oceania such as Papua New Guinea. DISTRIBUTION  ROUTE OF TRANSMISSION a) naturally acquired infections are via - the bite of infected female Anopheles mosquitoes. b) Malaria is also transmitted via blood transfusion c) sharing of contaminated needles among IV drug abusers b) congenital transmission MORPHOLOGY Early trophozoites (ring) Trophozoites Developing trophozoites Immature Schizonts Common morphology of Mature Plasmodium spp Microgametocytes Gametocytes Macrogametocytes Sporozoites  LIFE CYCLE Intermediate host : human Definitive host : Female Anopheles mosquito Infective stage : sporozoite Infective mode : mosquito bite skin of human Parasitic position : liver and red blood cells Transmitted stage : gametocytes Schizogonic cycle in red cells: 48 hrs/P. vivax; 36-48 hrs/P. falciparum Sporozoite : tachysporozite and bradysporozite LIFE CYCLE Release sporozoites  LIFE CYCLE In mosquito (final host) Gametocytes(♀♂) gametes (♀♂) (blood—stomach) (stomach of insect) union of zygote rupture/release rounds up into sporozoites oocyst motile ookinete (Salivary glands) ( the body cavity side)  LIFE CYCLE In mosquito (final host)  LIFE CYCLE In human body 1. Exoerythrocytic stage bite/inject into sporozoites exoerythrocytic schizonts (mosquito blood) (hepatic cell) rupture/release exoerythrocytic sporozoites ( blood)  LIFE CYCLE There are two forms of sporozoites: -----tachysporozoite and bradysporozoite They are genetically distinct at the time of maturation when they enter the hepatic cells at the same time. tachysporozoite grow in the hepatic cell and multiply to form exoerythrocytic schizonts and then invade RBCs to produce malaria. Bradysporozoite is the cause of relapse of malaria. Bradysporozoite stay in the hepatic cells and will multiply later.  LIFE CYCLE 2. Erythrocytic stage early trophozoite later trophozoite P.f/36-48hrs P.v/48hrs merozoite immature schizont Mature schizont *the process from trophozoite to merozoite is called schizogony.  LIFE CYCLE 3. Gametogenesis ----After completing a few schizogonic cycles, some merozoites develop into sexual cells, the male and female gametocytes. They continue their development in the mosquito.  LIFE CYCLE Erythrocytic cycle Human blood stage is the diagnostic stage 05/06/2024; Slide 17 MORPHOLOGY Infected red blood cell Plasmodium Plasmodium vivax Plasmodium Plasmodium falciparum malariae ovale Same size and shape Larger than the Same size as the Enlarged and as the non-parasitized non-parasitized non-parasitized most of them are RBC ones ones or slighly oval in shape Contain 6-12 coarse Contains red smaller. with fimbriated granules brick red dots (Schuffner’s dots) Contain fine margins. (Maurer’s cleft) on the surface stippling Contain Some show Irregular in shape (Ziemann’s prominent basophilic stippling stippling). Schuffner’s dots  MORPHOLOGY Trophozoite – ring form Plasmodium Plasmodium Plasmodium Plasmodium falciparum vivax malariae ovale Small rings with a Ring form with Ring form Ring form with a red staining nuclear a nuclear dot resembles with nuclear dot and a dot and a small and a crescent P. vivax with a crescent of amount of blue- of cytoplasm nuclear dot and cytoplasm staining cytoplasm Ring form is a crescent of Sometimes double well-defined, cytoplasm but dots with a prominent thicker and Sometimes multiple central vacuole more-intensely rings stained MORPHOLOGY ring stage Plasmodium falciparum Plasmodium vivax MORPHOLOGY ring stage Plasmodiummalariae Plasmodium ovale MORPHOLOGY Trophozoite - developing Plasmodium Plasmodium Plasmodium Plasmodium falciparum vivax malariae ovale Pigments group Larger and have Solid blue Resemble to P. together in a one an irregular cytoplasm like thick vivax but more compact form amoeboid form band across the compact and less Rarely amoeboid RBC amoeboid form Large round appearance. nucleus and Large and Often has a blob of irregularly brown malarial distributed pigment in the RBC cytoplasm Big nucleus MORPHOLOGY Trophozoite Plasmodium falciparum vivax malariae ovale 05/06/2024; Slide 24 MORPHOLOGY Trophozoite - developing Plasmodium falciparum Plasmodium vivax MORPHOLOGY Trophozoite - developing Plasmodiummalariae Plasmodium ovale MORPHOLOGY Schizonts Plasmodium Plasmodium Plasmodium Plasmodium falciparum vivax malariae ovale Only present in blood Contains 12 - 24 Contains 6 - 12 Contains 6 - 12 in pre-terminal phase merozoites merozoites merozoites of infection Infected RBC is Infected RBC is not Infected red blood Contain 12 - 24 enlarged enlarged cell is enlarged and merozoites (nuclear Fill the whole RBC Fill the whole RBC is an oval shape. dots) Rosette appearance Resemble P. RBC with schizont is malariae but pigment not enlarged. is darker. 05/06/2024; Slide 27 MORPHOLOGY Schizonts Plasmodium falciparum vivax malariae ovale 05/06/2024; Slide 28 MORPHOLOGY Schizont Plasmodium falciparum Plasmodium vivax MORPHOLOGY Schizont Plasmodiummalariae Plasmodium ovale  MORPHOLOGY Gametocytes Plasmo- falciparum vivax malariae ovale dium Male Banana shaped, Round, smaller, Round, smaller, Round, smaller, gameto- shorter and fatter, light blue light blue light blue cyte light blue cytoplasm, cytoplasm, diffuse cytoplasm, large cytoplasm, diffuse diffuse nucleus nucleus diffuse nucleus nucleus Female Round, larger, Round, larger, Round, larger, Banana shaped, gameto- dark blue dark blue dark blue longer and thinner, cyte cytoplasm, small cytoplasm, small cytoplasm, small dark blue cytoplasm, and compact and compact and compact compact nucleus nucleus nucleus nucleus 05/06/2024; Slide 31 MORPHOLOGY Gametocyte Plasmodium falciparum vivax malariae ovale 05/06/2024; Slide 32  MORPHOLOGY Gametocytes Plasmodium falciparum 27, 28: Mature macrogametocytes (female); 29, 30: Mature microgametocytes (male) Plasmodium vivax 28 and 29: Nearly mature and mature macrogametocyte (female); 30: Microgametocyte (male) MORPHOLOGY Gametocytes Plasmodiummalariae 23: Developing gametocyte; 24: Macrogametocyte (female); 25: Microgametocyte (male) Plasmodium ovale 24: Macrogametocyte (female); 25: Microgametocyte (male). MORPHOLOGY Plasmodium falciparum 1: Normal red cell; 2-18: Trophozoites 2-10 correspond to ring-stage trophozoites; 19-26: Schizonts ( 26 is a ruptured schizont); 27, 28: Mature macrogametocytes (female); 29, 30: Mature microgametocytes (male) 05/06/2024; Slide 35  MORPHOLOGY Plasmodium vivax 1: Normal red cell; 2-6: Young trophozoites (ring stage parasites); 7-18: Trophozoites; 19-27: Schizonts; 28 and 29: Macrogametocytes (female); 30: Microgametocyte (male) 05/06/2024; Slide 36 MORPHOLOGY Plasmodium malariae 1: Normal red cell; 2-5: Young trophozoites (rings); 6-13: Trophozoites; 14-22: Schizonts; 23: Developing gametocyte; 24: Macrogametocyte (female); 25: Microgametocyte (male) 05/06/2024; Slide 37 MORPHOLOGY Plasmodium ovale 1: Normal red cell; 2-5: Young trophozoites (Rings); 6-15: Trophozoites; 16-23: Schizonts; 24: Macrogametocyt es (female); 25: Microgametocyte (male) 05/06/2024; Slide 38 MORPHOLOGY Comparison MORPHOLOGY Comparison  MORPHOLOGY Comparison Plasmo- falciparum vivax malariae ovale dium RBC Normal; Enlarge; Normal; Enlarge; Rarely stippling stippling No stippling stippling Present in Ring and All stages All stages All stages blood gametocyte Tropho- Small ring; Ring and Ring and Ring and zoite sometimes 2 amoeboid band form irregular dots & multiple shape rings Schizont Rarely seen; > > 12 < 12 < 12 12 merozoite merozoite merozoite merozoite Gameto- 05/06/2024; Banana shaped Round Slide 41 Round Round cyte Stipple: dots PATHOGENESIS Paroxysm Splenomegaly and anemia (attack of malaria) liberation of ----Rupture of the infected RBCs and merozoites and destruction of normal RBCs enhance malarial phagocytosis stimulate phagocytes to pigment; RBC grow in number and enhance in function. debris into the Finally, lead to anemia and enlargement of blood stream. the spleen. PATHOGENESIS Relapse Malignant malaria ----a specific attack that it is up to Malaria caused by P.f. is more months or even years after the severe than that caused by other primary attacks. plasmodia. ----The bradysporozoites in the ----The serious complication of liver spend a rest and sleeping P.f. involves cerebral malaria times of months or even years , (involving the brain); massive then they start develop in haemoglobinuria (blackwater fever) exoerythrocytic stage and in which the urine becomes dark erythrocytic stage. at this time, the incolor, because of acute patient occurs paroxysm , showing hemolysis of RBC; acute as periodic fever like the primary respiratory distress syndrome; attacks, it is called relapse. severe gastrointestinal symptoms; ----Relapse only occurs in P.v. shock and renal failure which may cause death.  LABORATORY DIAGNOSIS Microscopic examination – Thick and thin smear of peripheral blood – Staining -Giemsa or Wright’s stain -Fluorescent staining Quantitative buffy coat (QBC) test Serological tests Culture of malarial parasites  LABORATORY DIAGNOSIS - newer methods of diagnosis Fluorescence microscopy Rapid antigen detection tests (Parasite-F test, dual antigen test) Molecular diagnosis (DNA Probe, PCR)  LABORATORY DIAGNOSIS Thick and thin blood smear Both can be prepared on a glass slide Thick blood smear – Thick layer of lysed erythrocytes – 30x the concentration of thin blood smear – Useful in screening the malarial parasites – But morphology of parasites hard to differentiate – Thus species identification becomes more difficult Lyse: burst  LABORATORY DIAGNOSIS Thick and thin blood smear Thin blood smear – Thick blood smear show positive results, perform thin blood smear to identify species – Also do infected RBC count to determine % of parasitemia – However, malaria parasites may be missed on a thin blood smear when there is a low parasitemia  TREATMENT Chlorquine and quinine----anti-erythrocytic stage drugs. Primaquine and pyrimethamine ----anti- exoerythrocytic stage drugs.  PREVENTION Chemoprophylaxis -----Chloroquine / pyrimethamine used for prophylaxis of malaria -----Chemotherapy: 1 week before entry into the endemic area ; for 4 weeks after returning from the endemic area.  PREVENTION Mosquito control (1). Reconstruction of environment: eradicate the breeding places of moquitoes. (2). Spry insecticides: DDVP and so on. (3). Use mosquito nets, screen, or mosquito repellents to protect the person from mosquito bites.