toxoplasma.pptx
- 2. HISTORY MORPHOLOGY LIFECYCLE TRANSMISSION PATHOPHYSIOLOGY CLINICAL MANIFESTATIONS DIAGNOSIS TREATMENT PREVENTION
- 3. SIR HENRY NICOLLE TOXOPLASMOSIS GONDII DISCOVERED AND NAMED BY CHARLES JULES HENRY NICOLLE (1866-1936) AND MONCEAUX IN 1908. AN INTRACELLULAR PARASITE WAS ISOLATED FROM THE LIVER AND SPLEEN OF A WILD AFRICAN RODENT CTENODACTYLUS GONDII. A YEAR LATER THEY CALLED IT TOXOPLASMA GONDII BECAUSE OF ITS ARCHED SHAPE (TOXON: ARCH) AND BECAUSE OF THE COMMON NAME IN WHICH IT WAS FOUND, THE GONDII.
- 5. 1908 1923 Janku Chorioretinitis 1939 Wolff and Col Congenital meningoencephalitis 1948 Sabin and Feldman Reaction Serological 1949 Frenkel Hypersensitivity test 1970 renkel & hutchison True Form of Transmission
- 6. MORPHOLOGY • ASEXUAL FORMS TACHYZOITE BRADYZOITE (TISSUE CYST) • SEXUAL FORM OOCYST
- 7. TACHYZOITES ACTIVELY M U LT I P LY I N G F O R M CRESCENT SHAPE SEEN IN ACUTE INFECTION INFECT ALL THE NUCLEATED M A M M A L I A N CELLS INSIDE THE HOST CELL, THE TACHYZOITES ARE S U R RO U N DE D BY A VACUOLE - ASEXUAL M U LT I P L I C AT I O N OCCURS - ROSETTES
- 8. BRADYZOITES RESTING STAGE OF THE PARASITE SEEN IN C H RO N I C INFECTIONS MOST C O M M O N SITE IS MUSCLES A N D BRAIN INSIDE THE CYST - SLOWLY M U LT I P LY I N G TROPHOZOITES ARE CALLED AS BRADYZOITES
- 9. OOCYST SEXUAL F O R M OF THE PARASITE F O U N D O N LY IN CATS A N D FELINES
- 10. LIFE CYCLE
- 11. TRANSMISSION INGESTION OF SPO RU LA TED O O C YSTS FRO M C O N TA M IN A TED SOIL, F O O D OR WATER INGESTION OF TISSUE CYST C O N TA I N I N G BRADYZOITES F RO M U N D E RC O O K E D MEAT BY BL O O D TRA N SFU SIO N , N EED LE STIC K IN JU RIES, O RG A N TRANSPL ANTATION TRANSPLACENTRAL TRANSMISSION LABORATORY ACCIDENTS ( TACHYZOITES IN BLOOD)
- 12. The Tachyzoites arereproduced Dissemination Following route lymphatic/ hematogenous Penetrates the intestinal wall PATHOPHYSIOLOGY
- 13. PATHOGENESIS • FORMATION OF TACHYZOITES –MULTIPLY AND DISSEMINATION • LYMPHATIC TISSUE-FOLLICULAR HYPERPLASIA • SKELETAL MUSCLE • MYOCARDIUM-FOCAL NECROSIS (MUSCLE CYSTS) • RETINA ,CHOROID-GRANULOMATOUS LESION • LUNGS-INTERSTITIAL PNEUMONIA • CNS – NECROSIS AND MICROGLIAL NODULES • OTHER ORGANS-PANCREATITIS,GLOMERULONEPHRITIS
- 14. • IN IMMUNOCOMPETENT INDIVIDUALS,IMMUNE MECHANISMS LIKE MACROPHAGES,CD8+ CELLS,NK CELLS,INTERFERON GAMMA,IL-2,12 • KILL OR INHIBIT THE REPLICATION • IMMUNOGLOBULINS A,M,G DEVELOP • TISSUE CYSTS BECOME ACTIVE WITHIN 7 DAYS AND REACTIVATION OCCURS
- 15. ACUTE OR CHRONIC • THE RAPIDLY MULTIPLYING CRESCENTRIC CELL (TACHYZOITES ) INITIATE THE ACUTE STAGE OF DISEASE •IN FUTHER DEVELOPMENT THEY PENETRATE NEW CELLS ESPECIALLY EYE AND BRAIN. •FURTHER DEVELOPMENT SLOWS DOWN IN THESE ORGANS CALLED AS BRADYZOITES TO FORM A QUIESCENT TISSUE CYSTS • THE EVENT LEAD TO CHRONIC STAGE OF DISEASE
- 16. CLINICAL MANIFESTATIONS FEATURES IN I M M U N O C O M P E T E N T INDIVIDUAL FEATURES IN IMMUNODEFICIENT INDIVIDUAL CO N G E N I TA L TOXOPLASMOSIS OCULAR TOXOPLASMOSIS
- 17. IMMUNOCOMPETENT ACUTE STAGE-ASYMPTOMATIC SYMPTOMATIC HEADACHE,FATIGUE MALAISE FEVER CERVICAL LYMPHADENOPATHY • SUBOCCIPITAL,SUPRACLAVICULAR,INGUIN AL,MEDIASTINAL(DISCRETE,MULTIPLE,VARI ABLE IN CONSISTENCY)
- 18. IMMUNOCOMPROMISED • ACUTE INFECTION OR REACTIVATION OF BRADYZOITES • DEADLIEST-TOXOPLASMIC ENCEPHALITIS • EITHER FOCAL DYSFUNCTION TO NON FOCAL MENINGOENCEPHALITIS • DUE TO VASCULITIS,EDEMA AND HEMORRHAGE • ALTERED MENTATION(75%),SEIZURES(33%), FOCAL NEUROLOGICAL SIGNS(60%), HEADACHE(56%), FEVER(50%) • BRAINSTEM-CRANIAL NERVE PALSY,DYSMETRIA,ATAXIA • BASAL GANGLIA-HYDROCEPHALUS,CHOREIFORM MOVEMENTS, CHOREOATHETOSIS • DD-CRYPTOCOCCAL MENINGITIS,HSE,TM,CNS LYMPHOMA • LUNG-ARDS,HEMOPTYSIS,DIC
- 19. OCULAR TOXOPLASMOSIS BLURRED VISION,SCOTOMA,PHOTOPHOBIA MACULAR INVOLVEMENT-LOSS OF CENTRAL VISION, NYSTAGMUS SECONDARY TO POOR FIXATION EOM- CONVERGENCE-STRABISMUS FLARE UPS OF CHORIORETINITIS-DESTROY RETINAL TISSUE—GLAUCOMA CONGENITAL LESIONS-MASSIVE CHORIORETINAL DEGENERATION WITH EXTENSIVE FIBROSIS IN PATIENTS WITH AIDS,DIFFUSE RETINAL NECROSIS- FREE TACHYZOITES+CYSTS CONTAINING BRADYZOITES
- 21. OCCURS DURING FIRST TIME IN PREGNANCY INFECTION OF PLACENTA-HEMATOGENOUS INFECTION OF FETUS AS GESTATION INCREASES-RATE OF TRANSMISSION INCREASES BUT SEVERITY DECREASES INFECTED CHILDREN INITIALLY ASYMPTOMATIC,PERSISTENCE OF T.GONDII- REACTIVATION-MOST FREQUENTLY CHORIORETINITIS CHORIORETINITIS,STRABISMUS,BLINDNESS,EPILEPSY,ANEMIA,JAUNDICE,RASH MICROCEPHALY,INTRACRANIAL CALCIFICATION,HYDROCEPHALUS,PNEUMONITIS TRIMESTER FIRST SECOND THIRD Trasmission rate 10-25% 30-54% 60-65%
- 22. DIAGNOSIS DIRECT MICROSCOPY DETECTION OF TACHYZOITES IN B LO O D A N D TISSUE CYST IN TISSUE BIOPSY STAINING METHODS: o GIEMSA o PAS o SILVER STAINS o IMMUNOPEROXIDASE STAIN
- 23. SEROLOGY DETECTION OF TOXOPL ASMA ANTIGEN BY ELISA DETECTION OF TOXOPL ASMA ANTIBODY BY o SABIN F E L D M A N DYE TEST o INDIRECT FLUORESCENT ANTIBODY TEST o IGM ELISA o IGG ELISA o IGG AVIDITY TEST
- 24. • PARALLEL IGG TESTING -4 FOLD RISE IN PAIRED SERA OF 3 WEEKS APART- ACUTE INFECTION • IGG –LOW AVIDITY-ACUTE INFECTION(<3 MONTHS) • HIGH -CHRONIC INFECTION(>3 MONTHS) • PRESENCE OF IGA,M,E –ACUTE INFECTION • OTHER METHODS-DOUBLE SANDWICH IGM ELISA & IGM IMMUNOSORBENT ASSAY
- 25. MOLECULAR METHODS POLYMERASE CHAIN REACTION AMPLIFICATION OF B1 GENE DETECTION OF T.GONDII DNA SAMPLES o AMNIOTIC FLUID o PERIPHERAL BLOOD o CSF o URINE o AQUEOUS & VITREOUS FLUID
- 26. TREATMENT • GOAL-TO ARREST THE REPLICATION OF PARASITE AND PREVENT FURTHER DAMAGE TO ORGANS INVOLVED • IMMUNOCOMPETENT • IMMUNOCOMPROMISED • CONGENITAL
- 27. IMMUNOCOMPETENT • NOT REQUIRE SPECIFIC THERAPY • IF OCULAR+ ,TREATED FOR 1 MONTH – PYRIMETHAMINE+SULFADIAZINE/CLINDAMYCIN OR PREDNISONE
- 28. IMMUNOCOMPROMISED • AIDS PATIENTS SEROPOSITIVE FOR T.GONDII –CD4+T LYMPHOCYTE COUNT<100/MCGL(SCREENING AIDS PATIENTS) • IF CD4+T LYMPHOCYTE COUNT>200,NO NEED OF PROPHYLAXIS • TRIMETHOPRIM-SULFAMETHOXAZOLE • NOT TOLERATE-DAPSONE+PYRIMETHAMINE • ATOVAQUONE +/_ PYRIMETHAMINE • PROPHYLACTIC MONOTHERAPY- DAPSONE,PYRIMETHAMINE,AZITHROMYCIN,CLARITHROMYCIN,AEROSOLIZE D PENTAMIDINE • PATIENT+HIV- CD4+T LYMPHOCYTE COUNT>200 FOR ATLEAST 6 MONTHS AFTER ART+ASYMPTOMATIC---DISCONTINUE THE PROPHYLAXIS
- 29. CONGENITAL INFECTION • NEONATES-ORAL PYRIMETHAMINE(1MG/KG) • SULFADIAZINE (100 MG/KG) • FOLINIC ACID FOR 1 YEAR • PREDNISOLONE(1MG/KG PER DAY)-MAY BE USED • PREGNANT-SPIRAMYCIN(IN ACUTE CASE EARLY IN PREGNANCY) • PYRI/SULFA/FOLINIC ACID –AFTER 18 WEEKS OF PREGNANCY
- 30. PREVENTION IS BETTER THAN CURE • AVOIDANCE OF HUMAN CONTACT WITH CAT FECES IS HIGHLY IMPORTANT • CHANGING OF CAT LITTER AND SAFE DISPOSAL CAN PREVENT TRANSMISSION •MEAT SHOULD BE COOKED TO INTERNAL TEMPERATURE OF 74-75DEGREE CELCIUS • WASH YOUR HANDS AFTER HANDLING RAW MEAT • PROTECT CHILDREN'S PLAY AREAS FROM CAT AND DOG DROPPINGS •WASH YOUR HANDS VERY WELL AFTER BEIN G IN CONTACT WITH SOIL POSSIBLY CONTAMINATED BY ANIMAL FECES • SCREENING OF IMMUNOCOMPROMISED FOR ANTIBODY TO T.GONDII • PREGNANT WOMEN SHOULD AVOID CONTACT WITH KITTENS
- 31. REFERENCES • PRINCIPLES AND PRACTICES OF INFECTIOUS DISEASES,8TH EDITION- MANDELL,DOUGLAS