BLOK 17 Dr.dr. Mahardika AW, DTM&H,MKes Dept.of Parasitology Fac.of Medicine GMU Yogyakarta

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1 BLOK 17 Dr.dr. Mahardika AW, DTM&H,MKes Dept.of Parasitology Fac.of Medicine GMU Yogyakarta 8/7/2012 dr.dika-prst 1

2 TOXOPLASMOSIS 8/7/2012 dr.dika-prst 2

3 Introduction Morphology & Life Cycle Transmission Toxoplasmosis in Human Immune Responses & Diagnosis Prevention & Control 8/7/2012 dr.dika-prst 3

4 INTRODUCTION Toxoplasma gondii : intracellular protozoa parasite (non-flagellated organism) that infect most species of warm blooded animals including human Causing desease : Toxoplasmosis The name Toxoplasma (toxon=arc or bow, plasma= life) is derived from its crescent shape. Toxoplasma gondii was first discovered by Nicolle and Manceaux in 1908 in a rodent, Ctenodactylus gundi. 8/7/2012 dr.dika-prst 4

5 World wide, affecting most of warmblooded animal. More common in warm climate & at lower altitudes than in cold climates and mountainous regions. Related to prefer for eating raw or undercooked meat Related to the frequency of stray cats in a climate favoring survival of oocyst. 8/7/2012 dr.dika-prst 5

6 1. Tachyzoites 2. Bradyzoites and Tissue cysts 3. Enteroepithelial asexual and sexual stages 8/7/2012 dr.dika-prst 6

7 Toxoplasma gondii TAXONOMI : -Filum :Aplicomplexa -Klas :Sporozoastida -Subklas :Coccidiasina -Ordo :Eimeriorina -Familia :Toxoplasmatidae VARIANT 1. Virulent (Type I: RH Strain) 2. Less virulent (Type II, III) 8/7/2012 dr.dika-prst 7

8 Tachyzoites Size: Approximately 2 x 6 um They measured 4.7 X 2.1 um in size Shape: is often cresent-shaped. Its anterior (conoidal) end is pointed and its posterior end is round Description: The term"tachyzoite" (tachos=speed in Greek) was coined by Frenkel to describe the stage that rapidly multiplied in any cell of the intermediate host and in nonintestinal epithelial cells of the definitive host. 8/7/2012 dr.dika-prst 8

9 The tachyzoite enters the host cell by active penetration of the host cell membrane. After entering the host cell the tachyzoite becomes ovoid in shape and becomes surrounded by a parasitophorous vacuole (PV). It has been suggested that the PV is derived from both the parasite and the host The tachyzoite multiplies asexually within the host cell by repeated endodyogeny. 8/7/2012 dr.dika-prst 9

10 Proliferation in host s cells Live parasite actively enter M@ multiply in parasitoporous vac (lysozym & fagosome: no fusion ) Opsonized parasite (immune serum/moab) enter M@ destroyed (lysozym & fagosome: fusion ). 8/7/2012 dr.dika-prst 10

11 Bradyzoites Size: Approximately 7um x 1.5 um Shape: Bradyzoites differ only slightly from the tachyzoites. They are more slender than tachyzoites and their nucleus is located more to the posterior end compared to atachyzoites b Toxoplasma tissue cyst or bradyzoite in muscle (a) and brain tissue (b) 8/7/2012 dr.dika-prst 11

12 Bradyzoite: The term "bradyzoite" (brady = slow in Greek) It is used to describe the organism multiplying slowly within a tissue cyst. Bradyzoite is a synonym of cystozoite. The terms tachyzoite and bradyzoite replace the previously used term trophozoite and in a sense these forms are subsets of trophozoites (trophicos = feeding in Greek). A tissue cyst is a collection of bradyzoites surrouned by a well-defined host cell membrane. Bradyzoites differ structurally only slightly from tachyzoites. They have a nucleus situated toward the posterior end whereas the nucleus in tachyzoites is more centrally located 8/7/2012 dr.dika-prst 12

13 Entero Epitelial Cycle Viable > 1 year Mode of cat infection Time period to shed of oocyst Ingest sporulated oocyst Fed acutely ill mammals with tachyzoit Fed chronically infected mammal + tissue cyst days 9 11 days 3 5 days 8/7/2012 dr.dika-prst 13

14 Unsporulated Oocyst: Size: 10 x 12 um in diameter (Dubey, 1993). Shape: Supspherical to shperical (Dubey, 1993) Description: Unsporulated oocysts are subspherical to spherical and are 10 x 12 um in diameter. The oocyst wall contains two colorless layers. Micropyle and polar granules are absent. The sporont almost fills the oocyst, and sporulation occurs outside the cat within 1 to 5 days depending upon aeration and temperature (Dubey, 1993). 8/7/2012 dr.dika-prst 14

15 Sporulated Oocyst : : Size: 11 x 13 um in diameter. Shape: Subspherical to ellisoidal. Upon sporulation the sporont divides into two round masses called sporoblasts." They later elongate and differentiate to form sporocysts. Within each sporocyst four sporozoites develop. Each sporulated oocyst contains two ellipsoidal sporocysts Sporocysts measure 6 x 8 um Each sporocyts contains four sporozoites. 8/7/2012 dr.dika-prst 15

16 Other stages of T. gondii: Schizont Merozoites Microgametes Macrogametes Develop in the small intestine of definitive host (Cat) 8/7/2012 dr.dika-prst 16

17 Life Cycle 8/7/2012 dr.dika-prst 17

18 Oocyst maturation at the external environment (1-5 days) 8/7/2012 dr.dika-prst 18

19 MODE of Infection in HUman : Ingestion of undercooked infected meat containing Toxoplasma cyst. Ingestion of the oocyst from fecally contaminated hands,food or water. Organ transplantation or blood transfusion Transplasental from infected mother Accidental inoculation of tachyzoite. 8/7/2012 dr.dika-prst 19

20 Cycle in humans (an accidental host) Oocyst or bradyzoit form are ingested cyst wall digested Sporozoite enter epithelial cells tachizoite form, Infecting all cell type desiminated via lymph & Circulation to all organs. After 2 weeks tachyzoite deminished & develop bradyzoite (Chronic form) in tissue preferably in brain, cardiac & Striated muscle & retina 8/7/2012 dr.dika-prst 20

21 pathology 1.Acquired Toxoplasmosis In Immunocompetent: - generally inapparent, no clinical manifestation - 20% cases with lymphadenopathy & moderate fever - 38% with asthenia & neuthropenia During chronic phase tissue cyst are well controlled by immune system which is continuously stimulated Toxo Ag. Immune System is deeply affected( leukemia, cancer Tx, HIV): Reactivation intense proliferation of tachizoites diseminated : enchephalitis, headache, altered mental status, visual field loss, etc. 8/7/2012 dr.dika-prst 21

22 2. Congenital toxoplasmosis Transmission rate of the first infection in pregnant women to baby : 40% in France (screening is compulsory for pregnant women) transmission rate : 10%o The severity of congenital Tox is associated with time of infection. The earlier in pregnancy the infection occurs, the more severe the fetal infection. The risk of the baby's infection Depend partly upon the timing of the mother's infection : Distribution of time of congenital infection: - 1% in peri conceptual period - 12% between 6 16 weeks - 20% between weeks - 20% - 80% between 28 weeks delivery 8/7/2012 dr.dika-prst 22

23 Infection : in early stages spontaneus abortion & in utero death in first term patology in embryogenisis : microcephaly, intracranial calcification, neurologic : convulsion, tonus impairment, mental retardation, low intelectual quotion etc. occular : microphthalmy, chorioretinitis blindness. Hepatitis, hepatomegaly & acites : frequent in infection at first half of pregnancy. Infection at 2 nd half of pregnancy less severe chorioretinitis occure after several months/years. Early postnatal treatment reduce freq. of chronic retinitis 60% to 10%. 8/7/2012 dr.dika-prst 23

24 8/7/2012 dr.dika-prst 24

25 Immune responses to Toxoplasmosis Both humoral & Cellular It s role in protection : - not clear yet - seem to depend on the host - in general CMI predominan Humoral Immune Responses Classix Dx : detection of specific IgG & IgM IgM : appear 2 weeks after infection (acute phase), than decline. IgG : appear later & maximal 2 months after infection, than decrease to a relatively low & persist for live proof of previous infection Problem : sometimes IgM still positive: months years. 8/7/2012 dr.dika-prst 25

26 Conventional serologic test - not adequate to Dx congenital Toxo is - does not differentiate maternal & child IgG - IgM & IgA does not across placenta If infection accur early after conception specific Ab detected in 2 nd term of preg. 8/7/2012 dr.dika-prst 26

27 Cell Mediated Immunity Toxoplasmosis induce CMI ei. DTH Toxoplasmin skin test (inj. Toxo Ag i.d.) DTH Good correlation between DTH and the presence of circulating specific Ab. in human DTH responses develop months years skin test + : chronic infection / exclude acute Toxo is Modification of skin test : - using secretory & excretory Ag from culture of T.gondii specificity 100%, sensitivity 94.8% 8/7/2012 dr.dika-prst 27

28 T cell proliferation & blast transformation higher in chronic than in acute/normal ctrl In all : T lymphocytes is essential in generation of protective immunity to Toxo is CD4+ T cell important in controlling brain cyst development CD8+ T cell take role in inhibition cyst formation affect cyst number in organs. CD4+T cell as helper cytokine release (IFN- & IL-2) CD8+ T cells effector cells CD4 & CD8 act in synergy : CD4 help in development of resistance (acute stage) CD8 maintain immune response by inhibition cyst formation 8/7/2012 dr.dika-prst 28

29 Diagnosis of toxoplasmosis Morphologic tachyzoites in circulating WBC, bone marrow, lung, spleen, brain? histopathologic examination Culture or animal inoculation Serologic (mainly) Detection of parasite genetic material by PCR, especially in detecting congenital infections in utero. 8/7/2012 dr.dika-prst 29

30 IgM & IgG respon in Toxoplasmosis 8/7/2012 dr.dika-prst 30

31 Serologic test: Detectable levels of IgM antibody appear immediately before or soon after the onset of symptoms. IgM levels normally decline within 4 to 6 months, but may persist at low levels for up to a year IgG levels begin to rise 1 or 2 weeks after infection. Peak levels are reached in 6 to 8 weeks, then gradually decline over a period of months or even years. Low levels of IgG are generally detectable for life. IgG Avidity : differentiation between early and late Ab response immunocompromised individuals may not produce any IgM. Antibody levels do not correlate with severity oillness 8/7/2012 dr.dika-prst 31

32 2-4 weeks 8/7/2012 dr.dika-prst 32

33 Result of IgG Avidity for 18 patients with aquired toxoplasmosis examined by using the Toxoplasma gondii IgG Avidity EIA kit. 8/7/2012 dr.dika-prst 33

34 Test Before pregnancy testing for Toxoplasma antibodies when a woman is pregnant can be complicated and worrisome Because testing for toxoplasmosis infection can be difficult to interpret, the test may need to be sent to a special laboratory Women planning to become pregnant should discuss with their doctors whether they should have this blood test before pregnancy 8/7/2012 dr.dika-prst 34

35 Prevention of Toxoplasmosis Previous exposure prevents congenital Toxo transmission! Education : avoiding exposure to the parasite, mostly by simple hygienic measures. avoid exposure to oocytes : no cats or cat feces! no raw meat for you or your kitty! keep house cats inside - avoid stray cats! let anyone empty the cat box! cover the kid s sand box! wear gloves in the garden, wash your hands! wash all fruits and vegetables, wash hands carefully after handling raw meat, fruit, vegetables, and soil pregnant women should cook their meat until it is no longer pink and the juices run clear 8/7/2012 dr.dika-prst 35

36 Block-17 Dr.dr. Mahardika AW,DTM&H, Mkes Dept. of Parasitology FK UGM 8/7/2012 dr.dika-prst 36

37 MORPHOLOGY: Trichomonas vaginalis OLGI : Trophozoit form Cyst form : no 8/7/2012 dr.dika-prst 37

38 LIFE CYCLE : T. vaginalis 8/7/2012 dr.dika-prst 38

39 8/7/2012 dr.dika-prst 39

40 Trichomonad vaginitis :Female 25% Urethritis :male Prostatovesiculitis : male 8/7/2012 dr.dika-prst 40

41 Clinical Manifestation 8/7/2012 dr.dika-prst 41

42 Signs & Symptoms When do symptoms appear? Symptoms usually appear within 5 to 28 days of exposure in women. Men : Do not have signs & symptoms Pain in the groin urethritis non-specific Irritation inside of penis Mild discharge & slight burning after urination or ejaculation 8/7/2012 dr.dika-prst 42

43 Woman : Many women do have signs & symptoms 20% asymptomatic frothy, yellow-green vaginal discharge with a strong odor. The infection also may cause discomfort during intercourse and urination. Irritation and itching of the female genital area and, in rare cases, lower abdominal pain also can occur. 8/7/2012 dr.dika-prst 43

44 What are the complications of trichomoniasis? In pregnant women may cause : Abortion. premature rupture of the membranes and pre-term delivery. Low birth weight. The genital inflammation caused by trichomoniasis also might increase a woman's risk of acquiring HIV infection if she is exposed to the virus. Trichomoniasis in a woman who is also infected with HIV can increase the chances of transmitting HIV infection to a sex partner. 8/7/2012 dr.dika-prst 44

45 How is trichomoniasis diagnosed? To diagnose trichomoniasis, a health care provider must perform physical examination : In women, a pelvic examination can reveal small red ulcerations on the vaginal wall or cervix. Laboratory test: sample of vaginal discharge or urethral discharge to look for the disease-causing parasite. The parasite is harder to detect in men than in women. 8/7/2012 dr.dika-prst 45

46 Diagnosis Symptom & sign Laboratory: Wet-mount Culture 8/7/2012 dr.dika-prst 46

47 Treatment Metronidazole 250 mg 3x/d 10 days 2 gr/ single dose Tx of the sexual parner Female: Metro supo. -0-8/7/2012 dr.dika-prst 47

48 Thank You 8/7/2012 dr.dika-prst 48