Para 311 Midterms Review: Blood and Tissue Flagellates PDF

PARA 311 MIDTERMS LECT 4 Stages/Morphologic Form of Development: ✓ Amastigote (rounded or ovoidal) REVIEWER ✓ Promastigote BLOOD AND TISSUE FLAG...

PARA 311 MIDTERMS LECT 4 Stages/Morphologic Form of Development: ✓ Amastigote (rounded or ovoidal) REVIEWER ✓ Promastigote BLOOD AND TISSUE FLAGELLATES ✓ Epimastigote “These are the parasites that inhabit the tissue and the ✓ Trypomastigote blood of human with the aid of vector. “Not all are routinely recovered from human specimen Vector transmitted disease 1) Amastigote Stage (Leishmania) Primary mode of transmission: Insect bite − Ovoidal shaped Family: Trypanosomatidae o “This is the only form who is exempted in Genus: the fusiform because it appears to be Ovoid / rounded bodies without flagella A. Trypanosoma gambiense Brucei − Single nucleus with karyosome Trypanosoma rhodesiense complex o “Located off center Trypanosoma cruzi − Parabasal body B. Leishmania tropica Pathogenic o “Located adjacent to the blepharoplast Leishmania brasiliensis to man − Blepharoplast Leishmania donovani o “Dot like and not visible C. Leptomonas o “Attached to the axoneme Non-medically important D. Herpetomonas (Affects the vectors instead − Axoneme E. Phytomonas of humans) − Non-flagellated stage − 2 – 3 um − Found intracellularly in monocytes, endothelial cells “Two Genera of medically importance: Trypanosoma − Presence of large nucleus and Leishmania − Axoneme arises from kinetoplast and extend to anterior tip Characteristics: o “Kinetoplast is located anterior to the 1) Fusiform body → except for rounded or ovoidal nucleus 2) Nucleus location varies → depending on the − Diagnostic form for Leishmania form − Routinely recovered from human specimen 3) Single flagellum → arises anteriorly, spiral wave (Pathogenic) movement − Diagnostic form: o Shape; Rounded or ovoidal 4) Kinetoplast (collective term) → an accessory o Absence of external flagellum body found in many protozoa, primarily the Mastigophora; it contains DNA and replicates independently o Parabasal body → a structure near the nucleus in certain parasitic flagellates. “Cytoplasmic structure that supports the nuclear functions. 2) Promastigote (Leptomonas) o Blepharoplast → a basal body in certain − Spindle – shaped body flagellated protozoans that consists of a − Presence single free flagellum arising from minute mass of chromatin embedded in the kinetoplast at anterior end cytoplasm at the base of the flagellum. − 15 – 20 um 1.5 – 3.5 u “Serve as the site for growth of the Axoneme. − No undulating membrane 5) Axoneme → found at inner portion. − Diagnostic form for Leptomonas “Flagellum arises from this o “Leptomonas infects the gastrointestinal tract of vector “Basis for identification and significant in one form of − Not routinely recovered (culture) hemoflagellates: Location/ position of nucleus and − Diagnostic form: Kinetoplast. o Absence of undulating membrane 3) Epimastigote (Crithidia) − Spindle-shaped, longer, wider compared to Genus Leishmania promastigote − 3 species recognized according to clinical − Single nucleus with karyosome entities/Forms of Leishmania: o “Single nucleus is directed towards the 1) Cutaneous base. 2) Mucocutaneous o “Anteriorly located kinetoplast 3) Visceral o Single flagellum anteriorly located − Clinical disease: Leishmaniasis − Parabasal body − Differentiation among species causing disease in − Blepharoplast human is difficult → clinical grounds − Axoneme → Flagellum o Because the one that is recovered from − Undulating membrane along the course human sample is amastigote form which flagellum has same characteristics − Diagnostic form for Crithidia o “Crithidia would only be infecting the vector − Diagnostic form: o presence of undulating membrane (extends half of the total body length) “If they undergo same diagnostic form and life cycle to 4) Trypomastigote (Trypanosoma) differentiate them: Scientific name of insect vectors − Nucleus located anterior to Kinetoplast Leishmaniasis: Sandfly but they belong in different − Full body length undulating membrane genera o “Diagnostic form for Trypanosoma − Routinely recovered in humans Lifecycle: − Spiral-shaped ✓ Vector is in the form of sandfly → Bite of the o “In blood film, it is twisted in C, U, S) sandfly − Central nucleus ✓ Starting form is Promastigote which infects the − Single flagellum salivary glands of sandfly. ✓ The promastigote would invade the − Diagnostic form: reticuloendothelial cells o Posterior kinetoplast ✓ Amastigote has the ability to infect various tissues o Full body length undulating membrane and capable in tissue destruction ✓ After amastigote, it would go back to sandfly. ✓ The amastigote can be transmitted into the sandfly by Africa, Southeast Asia, countries in the biting to an infected person. mediterranean, Europe, & Central America ✓ Inside the sandfly the amastigote would go back to promastigote Disease ✓ Promastigote found in midgut of sandfly and may ✓ Wet/ Rural cutaneous leishmaniasis lead to proboscis of sandfly infecting the salivary ✓ Dry / urban cutaneous leishmaniasis gland. ✓ Oriental Sore/ Old World Cutaneous o It is in the Infective form because it goes Leishmaniasis back to its original form. Habitat Based on CDC: − Leishmania tropica is a parasite of skin of human Leishmaniasis is transmitted by the bite of infected 1) Endothelial cells of capillaries of infected female phlebotomine sandflies. areas 1. The sandflies inject the infective stage (i.e., 2) Nearby lymph nodes promastigotes) from their proboscis during 3) W/ in mononuclear cells, neutrophilic blood meals leukocyte 2. Promastigotes that reach the puncture wound are − not found peripheral blood phagocytized by macrophages and other types of o Sample is obtained from the ulcer site by mononuclear phagocytic cells. aspirating / biopsy of the infected site 3. Promastigotes transform in these cells into the − rarely disseminate tissue stage of the parasite (i.e., amastigotes) − mainly cutaneous 4. which multiply by simple division and proceed − Ulcers that are formed can be automatically healed to infect other mononuclear phagocytic cells but the doctors can prescribe meds 5. Parasite, host, and other factors affect whether the infection becomes symptomatic and whether Insect Vector – Genus Phlebotomus cutaneous or visceral leishmaniasis results. Species: Sandflies become infected by ingesting infected 1. P. papatasii cells during blood meals( , ). 2. P. sergenti In sandflies, amastigotes transform into promastigotes, develop in the gut (midgut for organisms in the Leishmania subgenus), and migrate to the Pathology & Symptoms proboscis. ✓ Incubation period: 2 – 4 weeks ✓ 1° lesion → reddish papule, itchy, gradually 2 Morphological Stages: enlarges, soft at center → rupture → ulcer 1) Amastigote formation (large raised with indurated edges) − Found intracellularly in vertebrate host (human) ✓ Ulcer may be single / multiple 2) Promastigote ✓ Most often seen on exposed area of body − Found midgut of intermediate host (sandfly) o “Lymph, face ✓ 2° bacterial infect are common “Primary lesion is in the form of red papule. It is like ❖ Leishmania tropica complex mosquito bite that can cause itching. Secondary bacterial − (tropica, aethiopica, major) infection is noted. o Complex name which is based on Diagnostic geographical distribution 1. Smear of exudate ulcer edge (Gold standard) ↓ Geographical distribution Wright/ Giemsa stain − Israel, Jordan, Iran, Portugal, Spain, Southern ↓ France, North Africa, Southern France, North Demonstrate amastigote stage mononuclear cells  2. Culture → Nubin, Nichol, Mc Neil 3. Biopsy of ulcer Diagnostic 4. Serology → IFA, ELISA 1. Smear from ulcer → demonstrate amastigote 5. Dermal test → “Montenegro dermal/skin test stage 6. Molecular → “Schizodeme and zymodeme o Same with L. tropica 2. Serology – CFT (Complement fixation test) Schizodeme involves analyzing kinetoplast DNA 3. Culture – Nubin, Nichol, Mc Neil Zymodeme →isoenzyme analysis Treatment/Therapy Montenegro dermal test→ similar to tuberculin skin 1. Berberine sulfate test and used for screening tool for those patient who has 2. Fuadin high risk in acquiring leishmania tropica. People with active form of the disease would test negative when the test is conducted using Montenegro. ❖ Leishmania donovani Treatment/Therapy − Visceral form of leishmania affects the Visceral 1. Faudin = very effective organs 2. Berberine Sulfate 2% sol. − Geographical Dist.: Worldwide – India, Asia, 3. Pentosam Southern, Russia, Northern China, East Africa, all countries bordering Mediterranean − Disease: Kala-azar / Visceral L., Death fever/ ❖ Leishmania brasiliensis complex tropical splenomegaly/ Dum dum fever − Braziliensis, panamensis, peruviana, guyanensis o Kala-azar and Dum dum fever is the − Synonym: L. tropica var. Americana most popular term used − Geographical Dist.: Central & South America − Some/ may be recovered with other leishmania species − Disease: Espundia/American/Leishmaniasis Uta o Coinfection may occur /Mucocutaneous leishmaniasis/New World o Same patient, different species Leishmaniasis − Main focus of infection → Visceral organ − Morph: resembles L. tropica o Amastigote is recovered in human − Visceral leishmaniasis (Kala-azar) is caused by sample parasites of the genus Leishmania, subgenus Leishmania, complex donovani (donovani, − Habitat: tissue cell, endothelial cell, monocyte, infantum, chagasi species) mucous membrane, nose mouth & pharynx − Habitat: − not found peripheral blood o Endothelial cells of visceral organ, − rarely localized in visceral organ Spleen liver, Intestinal mucosa, − Life Cycle: some w/ L. tropica Mesenteric glands − Insect vector – Sandfly o “Main clinical presentation is 1. Lutzomyia Hepatosplenomegaly enlargement of 2. Psychodopygus the spleen and liver. o Also gastrointestinal distress because of Pathology and Symptoms habitat intestinal ✓ start as papule → ulcer o It has the ability to migrate via ✓ invasion of tissue accepted w/ rapid necrosis → bloodstream/systemic disease deep, eroding, fungating & infiltrating ulcer − Mode of Transmission: bite of Sandfly ✓ “Aside from mucous membrane of nose and − Vector: mouth, the surrounding soft part of the face may 1. Phlebotomus argentipis be infected which could lead to disfigurement of 2. P. chinensis the face due to edema, mucosal lesion and 3. Lutzomyia secondary lesion. o Same with Leishmania brasiliensis  2. Ingestion infected feces of intermediate host by Pathology and Symptoms definitive host (only applicable to Reduviid bug) ✓ Papule formation at site of bite → bloodstream 3. Entrance / inoculation of parasite through abrasion / → engulf by macrophages & endothelial cells break skin ✓ Inc. pd. 2 – 4 months ✓ Headache, malaise, bleeding mucous membrane spleens & hepatomegaly ✓ Kala-azar→ black fever (blacking of the skin; Indian term) ✓ Mistaken for Malaria ✓ Anemia ✓ gastrointestinal distress Diagnostic 1. Demonstrate of parasite from blood & tissue Smear →amastigote 2. Serology → IFA, ELISA 3. Molecular → “Schizodeme and zymodeme Life Cycle of Brucie Complex: Transmission: Bite of tsetse fly Treatment/Therapy ✓ Starting form: Metacyclic trypomastigotes ✓ Potassium antimony tartrate ✓ Antimony tartrate →Which infecting the salivary gland ✓ Neostibosan ✓ Multiples in blood, lymph and spinal fluid. ✓ Hydroxy stilbamidine ✓ Invaded in the bloodstream: Bloodstream ✓ Isethionate Trypomastigote → second form “Leishmaniasis is less severe compared to ✓ Procyclic trypomastigote → third form present trypanosomiasis (nagagamot) in midgut “Vector of Leishmaniasis is not found in the Philippines. ✓ Epimastigote → multiple and migrate in The cases that was found had travel history. salivary gland ✓ Infective form: Metacyclic trypomastigote “Like a fly but has characteristic of mosquito Genus Trypanosoma Morph: Based on CDC: − Elongated spindle – shaped body w/ more or less During a blood meal on the mammalian host, an infected rounded posterior end & tsetse fly (genus Glossina) injects metacyclic Tapering anterior end usually 1 single trypomastigotes into skin tissue. − Parabasal body structure 1. The parasites enter the lymphatic system and − Axoneme Blepharoplast pass into the bloodstream − single flagellum arising from blepharoplast & 2. Inside the host, they transform into bloodstream runs anterior to form the margin of undulating trypomastigotes membrane 3. are carried to other sites throughout the body, − oval nucleus at center w/ central karyosome reach other body fluids (e.g., lymph, spinal fluid), and continue the replication by binary Mode of Transmission fission 1. Bite blood-sucking invertebrate The entire life cycle of African trypanosomes is 1) Glossina flies (Tsetse) →gambiense, represented by extracellular stages. The tsetse fly rhodesiense becomes infected with bloodstream trypomastigotes 2) Reduviid bug → cruzi when taking a blood meal on an infected mammalian host (4)(5) In the fly’s midgut, the parasites transform into procyclic o T. cruzi: the disease is a public health trypomastigotes, multiply by binary fission(6) , leave threat in most Latin American countries, the midgut, and transform into epimastigotes (7). The although cases due to blood derivatives epimastigotes reach the fly’s salivary glands and or blood transfusion has been reported in continue multiplication by binary fission (8). The cycle non-endemic regions. in the fly takes approximately 3 weeks. Rarely, T. b. Clinical Features gambiense may be acquired congenitally if the mother is ✓ The acute phase is usually asymptomatic, but infected during pregnancy. can present with manifestations that include fever, anorexia, lymphadenopathy, mild Species of Medical Importance hepatosplenomegaly, and myocarditis 1. Trypanosoma cruzi ✓ Romaña's sign may appear as a result of 2. Trypanosoma gambiense conjunctival contamination with the vector's 3. Trypanosoma rhodesiense feces. (ocular) ✓ A nodular lesion or furuncle, usually called ❖ Trypanosoma cruzi chagoma, can appear at the site of inoculation/ − Synonym: Schozitrypanum cruzi, Trypanosoma bite site. (elevated lump) escomele, Trypanosoma triatomae ✓ Chronic Chagas disease and its complications o Popular name ang gamitin can be fatal. − Disease: o South American Trypanosomiasis o (Sleeping sickness) → brain is the infection Mode of Transmission site. (Somnolence) 1. Bite of Reduviid bug which defecate at site of ▪ Stages of sleeping sickness inoculation Hemolymphatic → first stage: 2. Accidental ingestion of bug Blood and Lymph 3. Blood transfusion 4. Sexual intercourse, vertical transmission (studies Meningoencephalitis →second say/possible?) stage: causes swelling and Intermediate host → Reduviid bug damage to brain Triatomid bug o (Chagas disease) Assassin bug Kissing bug Cone nose bug Scientific name: 1. Panstrongylus megistus 2. Triatoma infestans Species 3. Rhodnius prolixus ✓ Geographical Dist.: Central & South America o T. cruzi: American trypanosomiasis was first described by Carlos Chagas in Brazil in 1909. The infection, Chagas' disease, is caused by the hemoflagellate Trypanosoma cruzi Life Cycle of Trypanosoma cruzi: transmission, and foodborne transmission (via food/drink ✓ Bite of reduviid bug, it would defecate contaminated with the vector and/or its feces). containing trypomastigote. (Starting form: Metacyclic trypomastigotes) Pathogenesis / Pathology & Symptoms ✓ Hind gut where Metacyclic trypomastigotes is ✓ disease manifested as painful chancre at site of found. inoculation → Chagoma → ulcerate → ✓ Second form: Amastigote form bloodstream → throughout body Arrows nanakahiwalay sa main: there would be ✓ Inc. pd. 7-14 days several cycles involving trypomastigote and amastigote ✓ High fever, edema, Romañas sign CNS manif. → forms. (It would go back and so on) encephalitis ✓ Third form: Bloodstream trypomastigote ✓ Heart – myocarditis ✓ Fourth form: epimastigote → present in midgut ✓ Lympadenopathy ✓ Five: Metacyclic trypomastigotes and migrates ✓ Splenomegaly to the hindgut ✓ Hepatomegaly Based on CDC: Diagnostic An infected triatomine insect vector (or “kissing” bug) 1. Microscopic demonstration of parasite stained takes a blood meal and releases trypomastigotes in its blood smear / lymph node aspirate feces near the site of the bite wound. 2. Culture NNN med. (Nubin-Nichol-Mc Neil) 1. Trypomastigotes enter the host through the bite 3. Serological: CF, DAT, IHT wound or intact mucosal membranes, such as the In CSF, detection of IgM in serum and elevate serum conjunctiva. proteins: Diagnostic for Chagas disease 2. Inside the host, the trypomastigotes invade cells near the site of inoculation, where they Prognosis differentiate into intracellular amastigotes ✓ Bad if CNS & Heart involved in cases of chagas 3..The amastigotes multiply by binary fission disease 4. and differentiate into trypomastigotes, and then are released into the circulation as bloodstream Treatment trypomastigotes. ✓ Primaquine = partially effective 5. Trypomastigotes infect cells from a variety of ✓ Nifurtimox = acute cases tissues and transform into intracellular ✓ There is no entirely available drug for treatment/ amastigotes in new infection sites. Clinical prevention of the disease manifestations can result from this infective ✓ Crucial diagnosis and treatment especially in cycle. The bloodstream trypomastigotes do not Hemolymphatic stage replicate (different from the African trypanosomes). Replication resumes only when the parasites enter another cell or are ingested by ❖ Trypanosoma gambiense another vector. The “kissing” bug becomes − Geographical Dist.: Central & West Coast infected by feeding on human or animal blood of Africa that contains circulating parasites − Disease: 6. The ingested trypomastigotes transform into o Gambian Sleeping Sickness epimastigotes in the vector’s midgut. o West African trypanosomiasis 7. The parasites multiply and differentiate in the midgut − Vector: Tse-Tse fly – Glossina sp. 8. and differentiate into infective metacyclic 1. Glossina palpalis trypomastigotes in the hindgut 2. Glossina techinoides. Other less common routes of transmission include blood Morphology transfusions, organ transplantation, transplacental − Spindle – shaped − 14-33 u X 1.5-3.5 u  − Nucleus centrally located B. Indirect hemagglutination test − Kinetoplast found posterior end of the body Treatment − Undulating membrane originating ✓ Pentamidine & Suramin (very effective if Blepharoplast given during blood - lymphatic stage) − Anterior flagellum runs along the edge of ✓ Tryparsamide 2-3 grams 15-20 weeks undulating membrane ✓ Metarsoprol → for late stage with CNS − Volutin granules cytoplasm (dark blue) involvement 2 stages of development 1. Trypomastigote → vertebrate host ❖ Trypanosoma rhodesiense 2. Epimastigote → Invertebrate host − Geographical Dist.: East Africa Habitat: − Disease: − Blood o East African Sleeping Sickness − LN o Rhodesian Sleeping Sickness − CSF − Morph, Pathogenesis, Life cycle = resembles T. gambiense − Connective tissue − Intracellular space brain − Symptomatology: o more severe manifestation than T. − Lymph channels throughout body gambiense o course rapid Pathogenesis o death early if CNS is involved fever, − Primary lesion Painful chancre at the bite myalgia, rigor, lethargy, mental site, fever, malaise headache disturbance − Other signs that manifest: Prevention: o Winterbottom’s sign → 1) Reduction of contact w/ Tse-Tse flies enlargement of cervical lymph nodes through control measures against them. (hemolymphatic stage) (traps, screen, insecticide) o Kerandel’s sign → delayed pain 2) Reduction of human infection by diagnosis (meningoencephalitis stage) & treatment of infected person − Typically, disease progresses from acute stage w/ trypanosome multiplying in the ❖ Trypanosoma brucei blood & lymphatic → to a sleeping sickness − Thin blood smear stained with Giemsa. stage with invasion CNS & terminates fatally − Typical trypomastigote stages (the only − CNS = tremors, character changes, stages found in patients), with a posterior somnolence, coma kinetoplast, a centrally located nucleus, an − Death results either from the disease or from undulating membrane, and an anterior intercurrent infection flagellum. Prognosis − The two Trypanosoma brucei species that ✓ Favorable if Rx instituted before cause human trypanosomiasis, T. b. involvement of the CNS. gambiense and T. b. rhodesiense, are Diagnostic undistinguishable morphologically. 1. Microscopic examination smear from lymph, Clinical Features blood & CSF − Infection occurs in 2 stages. A trypanosomal 2. Detect anti-trypanosome AB chancre can develop on the site of A. Immunofluorescence test inoculation.  − This is followed by a Hemolymphatic stage with symptoms that include fever, lymphadenopathy, and pruritus. − In the meningoencephalitis stage, invasion of the central nervous system can cause headaches, somnolence, abnormal behavior, and lead to loss of consciousness and coma. The course of infection is much more acute with T. b. rhodesiense than T. b. gambiense. Brief review: (diko alam if true yan sinabi ni maam hahaha) Primary lesion: ❖ Painful chancre → Trypanosoma gambiense ❖ Chagoma → Chagoma disease ❖ Chancre → Brucei complex ❖ Red papule → leishmania NOTE: Sa lifecycle sa pic nalang kayo mag base magulo siya SPOROZOA “There are more 100 species, but this 4 are only the (Plasmodium) one capable for human infection. Morphology: Some general characteristics are common to all malarial parasites. But differential features make it possible to identify species. 1. Trophic stage − The earliest form after invasion of red blood cells is a ring bluish cytoplasm with a dot like nucleus of red chromatin 2. Schizont − When growing, the parasites. Showing multiple masses of nuclear chromatin. 3. Merozoites − Are observed in mature schizont. Some of the trophozoites develop into gametocytes Malaria parasite belongs to or sexual stages, which are differentiated by Phylum: Apicomplexa compact cytoplasm and the absence of nuclear Class: Sporozoa division Order: Haemosporida Genus: Plasmodium STAGES OF DEVELOPMENT The rest listed in apicomplexa are classified as 1. Trophozoite Coccidia except for Plasmodium and Babesia − the earliest stage with 1 nucleus living which are classified as Haematozoa inside the red cells. The early trophozoite is Plasmodium ring-shaped with a red chromatin dot and a − A name which means nucleated mass and in small amount of blue cytoplasm when which the asexual cycle (schizogony) takes stained with Giemsa or Wright’s stain. place in the red blood cells of vertebrates and Two Types: the sexual cycle (sporogony) in mosquitoes. a) Early Trophozoite (Ring form) − “Causative agent for malaria (mal: bad, aria: − Ringlike appearance of plasmodium air) − “When stained in Giemsa stain, it o It was based on transmission and they consists of blue cytoplasmic circle thought that it is via air borne connected to chromatin red chromatin transmission later on they found out dot (which serves as nucleus). The that is vector borne space inside the ring/cytoplasm is o Transmission: Bite of mosquito known as Vacuole. o Vector: Anopheles mosquito − Sometimes the vacuoles are filled in 4 Species of Plasmodium which is sometimes basis in identifying 1. Plasmodium falciparum →Welch 1922 some species. 2. Plasmodium vivax → Grassi and Feletti b) Late Trophozoite (Developing trophozoite 1980 form) 3. Plasmodium malariae →Laveran 1881 − The remnants of cytoplasmic circle 4. Plasmodium ovale → Stephens 1922 and chromatin dot are still visible  − The appearance varies among − Large diffuse chromatin mass plasmodium species − Chromatin is centric o Some members serves this as b) Macrogametocytes diagnostic form. − It represents the female sexual form − Chromatin is eccentric “Easily Identified is the third, in terms of shape “To identify if its macro or micro: Look for chromatin mass/ position 2. Schizont − this stage is provided with nucleus divided into 8-24 merozoites. Each nucleus enclosed by some cytoplasm forming a merozoites Two Types: a) Immature Schizonts − Active chromatin replication − Multiple chromatin are seen NOTE: − Not a basis for differentiation ✓ P.vivax and P.falciparum are more b) Mature Schizonts common. − Characterized by fully developed stage ✓ Plasmodium is a wide distribution in of asexual trophozoite known as many tropical or subtropical regions of merozoites the world − To identify species of plasmodium we 1. P. falciparum observe the number and arrangement Morphological features of P. falciparum of merozoites “Instead of immature schizonts for identification, we look for mature schizonts Early trophozoite (ring form) − 1 or 2 red nuclei on the ring-like light blue cytoplasm; multiple infection in a cell. o Consist of more than 1 ring form inside RBC called multiple infection − infected RBC like normal RBCs. 3. Gametocytes − P. falciparum: only the early − sexual forms with 1 large compact and trophozoites and gametocytes can be seen round or elongated chromatin mass in the peripheral blood, − Pigment: Some parasites have granules of − Consist of scanty cytoplasm connected to pigment in their cytoplasm, other do not one (circle configuration) or two (called have any. headphone configuration) small Two Type: chromatin dots. a) Microgametocytes − Accole/ Applique form is evident − It represents the male sexual form o Meaning the ring forms are − Rounded/Roundish in shape directed near towards the edge of o With exception of P. falciparum, RBC which is crescent shaped  − The cytoplasm of RBC may contain − Typically consist of 8-36 merozoite Maurer’s dots (Average, 24); and cytoplasm also divided, o Appear to be red granules with each nucleus surrounded by a portion of irregular to comma shaped cytoplasm to form merozoites, malarial − Diagnostic for P. falciparum: Multiple pigment clumped. infection o 24 ata isasagot if ever tinanong? − Specimen of choice: Blood − For proper Identification: look for number − Common recovered in P. falciparum: or arrangement of merozoites Ring form and Gametocytes − These is where we can observed large Note: In parasitic studies, Giemsa stain is amount of merozoites recommended Question: How many RBC are seen in the picture? Answer: Only one “You can Identify the morphologic form inside the RBC NOTE: Gametocytes in P. falciparum are bigger compared to total diameter of RBC Developing Trophozoite − Same appearance in ring form Male gametocyte − Heavy cytoplasmic ring common − Sausage in shape; 1 o Cytoplasm is thicker − loose nucleus in center of it ; malarial − Fine pigment granules pigment − Mature forms only seen in severe infections − Diffuse − Diagnostic: Crescent shape Immature schizont − Dispersed / scattered central chromatin − Not useful for differentiation among with nearby black pigment usually visible members because all species has same − To differentiate male and female appearance in immature schizont gametocytes: look for the distribution of − Oval in shape, nucleus chromatin − Divided into 2-4 or more , − Chromatin bodies: Dispersed − Malarial pigment begins to concentrate in a mass. − Characterized by multiple chromatin bodies − There are also cytoplasm observed (Maurer’s Dot) Female gametocyte − Crescent in shape ; − 1 compact nucleus in center of it. − Chromatin bodies: Compact Mature schizont − Nucleus divided into  Life Cycle of Plasmodia (General) o What schizonts contains merozoite? Mature schizonts − The merozoites would then infect red blood cell Note: If the merozoite infect the Red blood cells, it is already in Erythrocytic cycle 2. Erythrocytic − Several developmental stages would take place − In the first path, some infected red blood cells containing merozoites would release merozoites to infect more Based sa sinabi ni maam + book: o A number of erythrocytic may occur − In the second path, some mature merozoites Human Cycle (Schizogony) would develop into gametocytes forms Primary mode of transmission − After this, it would go back to the body of − Bite of anopheles mosquito vector Origin: Mosquito Cycle (Sporogony) − Mosquito containing the infective form − Gametocytes ingested by the mosquito called (sporozoites) (sexual reproduction) − Sporozoite present/infecting salivary gland − There would be certain morphologic form − The sporozoite are transported to the that is transmitted back to the vector: peripheral blood until it reaches to liver and Gametocytes enter parenchymal cells (hepatocytes). − Once the mosquito bite the infected person, o First stop of Sporozoite: Liver cells it would be ingesting the gametocytes (hepatocytes) − Soon the male and female gametocytes − After which, there would be stages of would unite in the mosquito’s stomach and development that would take place form a fertilized cell called zygote in the Schizogony (Schizogonic cycle) form of ookinete. − Terms used to describe the cycle from − The ookinete would become encysted and mosquito to after it enters to human host matures into an oocyst. − Asexual reproduction o The oocyst is the form that contains sporozoites. Schizogony is divided into two cycle: − On complete maturation, the oocyst ruptures 1. Exoerythrocytic Cycle and releases numerous sporozoites which − Outside red blood cells migrate into the salivary gland of the − First cycle involved in schizogony which mosquito and ready to infect another human. takes place in Liver cells. − Stages of development would occur: It Based on CDC: would start from trophozoites, schizont − One the Schizonts/ infected liver cells ruptures, it would release merozoites  9. While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes. 10. The zygotes in turn become motile and elongated (ookinetes) 11. which invade the midgut wall of the mosquito where they develop into oocysts 12. 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. There are two forms of sporozoites: The malaria parasite life cycle involves two hosts. tachysporozoite and bradysporozoite During a blood meal, a malaria-infected female − They are genetically distinct at the time of 1. Anopheles mosquito inoculates sporozoites into maturation when they enter the hepatic cells the human host at the same time. 2. Sporozoites infect liver cells Tachysporozoite 3. and mature into schizonts − Common and present originally in saliva of 4. which rupture and release merozoites mosquito (Of note, in P. vivax and P. ovale a dormant stage − grow in the hepatic cell and multiply to [hypnozoites] can persist in the liver and cause form exoerythrocytic schizonts and then relapses by invading the bloodstream weeks, or even invade RBCs years later.) Bradysporozoite − is the cause of relapse of malaria. After this initial replication in the liver (exo- (hypnozoites) erythrocytic schizogony ), the parasites undergo o malaria relapse: same person, same asexual multiplication in the erythrocytes agent (erythrocytic schizogony ). − Bradysporozoite stay in the hepatic cells and 5. Merozoites infect red blood cells will multiply later. 6. The ring stage trophozoites mature into − Bradysporozoites are only produce by schizonts, which rupture releasing merozoites Plasmodium Vivax and Plasmodium 7. Some parasites differentiate into sexual ovale. erythrocytic stages (gametocytes).Blood stage Gametogenesis parasites are responsible for the clinical manifestations of the disease. − After completing a few schizogonic cycles, some merozoites develop into sexual cells, 8. The gametocytes, male (microgametocytes) and the male and female gametocytes. They female (macrogametocytes), are ingested by continue their development in the an Anopheles mosquito during a blood meal mosquito.. The parasites’ multiplication in the mosquito is − Part of Sporogony known as the sporogonic cycle Characteristic of Life Cycle Intermediate host: human (asexual phase) Definitive host/ Final host: Mosquito (sexual 3. regular phase) Infective stage: sporozoite A specific attack that it is up to months or even MOT: female mosquito bite skin of human. years after the primary attacks. Parasitic position : liver and red blood cells − The bradysporozoites in the liver spend a Transmitted stage : gametocytes rest and sleeping times of months or even Sporozoite: tachysporozite and bradysporozite years , then they start develop in exoerythrocytic stage and erythrocytic stage. at this time, paroxysm occurs , showing as periodic fever like the primary attacks, it is called relapse. − Relapse only occurs in P.vivax and P.ovale. Plasmodium falciparum Pathogenicity − Disease associated: Malignant Tertian − Main clinical feature of malaria: Paroxysm Malaria (attack of malaria) o Patient may experience nausea, − Paroxysm would start when red blood cell is vomitting, and diarrhea aside from infected by plasmodium paroxysm Question: When does paroxysm occur? Schizogony o Periodicity of paroxysm occurs → erythrocytic cycle every 36 to 48 hours In Exoerythrocytic, the patient is usually − Malaria caused by P.falciparum is most asymptomatic. severe than that caused by other plasmodia. Mechanism − “It affects all ages of Red blood cell from − liberation of merozoites and malarial young to mature RBC pigment; RBC debris into the blood stream. − About 50% of cells may be infected Symptoms/Signs (in a typical case) − It may enter to the kidney, CNS or liver − headache,lethargy, anorexia, nausea, − The serious complication of P.f. vomiting, diarrhea, ischemia o involves cerebral malaria (involving o Ischemia → loss of blood supply on the brain) organs because of blockage of o Kidney involvement known as capillaries (merozoites and other blackwater fever usually result debris) massive hemoglobinuria (presence of hemoglobin) in which the urine Paroxysm shows a succession of 3 stages: becomes in color, because of acute 1. The cold stage (chill/ rigor), lasting for 30 hemolysis of RBC; min to 1 hr. o acute respiratory distress syndrome; 2. The hot stage (fever), 1 to 4 hrs. severe gastrointestinal symptoms; 3. Sweating stage 1 to 2 hrs. shock and renal failure which may These stages happens in regular interval. We also cause comatose/ death. take note of the periodicity which vary from one − Thus, it is crucial to prompt diagnose and member to other. treatment Characteristic Laboratory Diagnosis 1. periodic ✓ laboratory diagnosis of malaria is confirmed 2. repeated by the demonstration of malarial parasites in  the blood film under microscopic ✓ Chemotherapy: 1 week before entry into examination. the endemic area; for 4 weeks after returning ✓ Thin film → to identify specific members from the endemic area. ✓ Thick film→ screening purposes (look for Mosquito Control any suspicious form of plasmodium ✓ Reconstruction of environment: eradicate the 1. Microscopy (Gold Standard) - “Thick and breeding places of mosquitoes. Thin Blood Smear” ✓ Use insecticides − stained with Giemsa or Wright’s stain ✓ Use mosquito nets, screen, or mosquito − perform multiple sets of blood films repellants to protect the person from (blood collected every 6 to 12 hours for up mosquito bites. to 48 hours) Note: Aside from bite of mosquito, it could 2. Serological test transmitted via: − ELISA →detection of antibodies ✓ blood transfusion → Transfusion Malaria − Rapid Diagnostic Test (RDT) → detection ✓ common in intravenous drug users via of antigen using monoclonal antibodies sharing of syringes →Mainline malaria Manner of Reporting ✓ Transplacental → Congenital Malaria A. Qualitative Plasmodium falciparum, ring form − + = 1-10 parasite/100 thick field − Thin blood film, Giemsa stained − ++ = 11-100 parasite/100 thick field − Early trophozoite- "Ring form" containing a − +++ = 1-10 parasite/thick field reddish chromatin "dot" and blue cytoplasm − ++++ = more than 10/ thick field "ring" B. Quantitative − A ring may contain double chromatin − A picture showing Maurer's dots on red cell membrane “we also count WBC Treatment − Chloroquine and quinine→ anti- erythrocytic stage drugs. − Primaquine and pyrimethamine → anti- exoerythrocytic stage drugs. Question: Which stage of plasmodium can these Trophozoites - Plasmodium falciparum: drugs kill? − Early trophozoites & late trophozoites have Answer: the characteristic signet ring shape. Question: Which set of drugs targeting more forms − Also, unique to P. falciparum is the of plasmodium? presence of multiple trophozoites in one Answer: Chloroquine and quinine because anti- cell. erythrocytic − Picture shows: developing trophozoite Prevention (thicker cytoplasmic circle) ✓ Chemoprophylaxis ✓ Chloroquine / pyrimethamine o Endemic in the Philippines malaria: Palawan o used for prophylaxis of malaria Plasmodium falciparum − Disease associated: Benign tertian malaria − Philippines o Because flulike sysmptoms − Organisms invades all age of red cells o Paroxysm would take place every − Malignant tertian malaria 48 hours − Multiple parasitization of red cells “multiple − Early trophozoites resembles ring forms of P. ring” falciparum − Small ring forms (1/6 diameter red cell), o Multiple infection is not common in double nuclear dots P. vivax − Cresent-shaped gametocytes Diagnostic form: Late trophozoite Plasmodium falciparum: − It is irregular shape like ameboid form with Blood Stage Parasites: Thin Blood Smears pseudopodia; within cytoplasm, brown ✓ Fig. 1: Normal red cell; pigment granules (malarial pigment→ ✓ Figs. 2-18: Trophozoites hemozoin) appear. ✓ Figs. 2-10 correspond to ring-stage − infected RBCs are pale in color,and have trophozoites); (fine red granules) ✓ Figs. 19-26: Schizonts (Fig. 26 is a ruptured − the remnants are still visible but it is not in schizont); the form of ring but rather ameboid form ✓ Figs. 27, 28: Mature macrogametocytes wherein the cytoplasm becomes irregular (female); (not perfect circle) ✓ Figs. 29, 30: Mature microgametocytes − Cytoplasmic granules are finer called : (male) Schüffner's dots ✓ Maurer’s dot can be seen − Diagnostic form: ameboid form ✓ Most likely there wouldn’t be changes in size of infected RBC in cases of P. falciparum (another clue) Mature schizonts − Contains 12 to 24 merozoites Gametocytes − Rounded same with P. ovale and P. malariae Plasmodium vivax: Blood Stage Parasites: Thin Blood Smears ✓ Fig. 1: Normal red cell; ✓ Figs. 2-6: Young trophozoites (ring stage parasites); ✓ Figs. 7-18: Trophozoites; Plasmodium vivax ✓ Figs. 19-27: Schizonts; − Worldwide (widest among) ✓ Figs. 28 and 29: Macrogametocytes − Only reticulocyte invaded (young RBC) ✓ Fig. 30: Microgametocyte − Single large ring succeeded by ameboid form ✓ Pigment: Schüffner's dots can be seen in large red cell − round gametocyte  ✓ There is a changes of size ✓ Pigment: Ziemman’s dots (increase/enlargement occurs in infected o Hardly visible which appears fine/ RBC) dust like gray colored granules ✓ P. vivax and P. Ovale has the same feature ✓ No changes of size in infected RBC because ✓ Cell distortion is possible but it is common it invades mature RBC more common in P. ovale NOTE: Figure 6-10 would show best the late trophozoite Plasmodium ovale − Single compact ring Plasmodium malariae − Large pale red cells − Single large compact ring or band forms − Targets young rbc − Invades old red cells (mature RBC) − Found in Africa − Ovoid gametocyte − Disease associated: Benign Tertian Malaria − Disease associated: Quartan malaria − Ring form and gametocytes=P. vivax − Diagnostic form: Late Trophozoite (in band o To differentiate the two: Mature form schizonts? o Instead of ameboid form it is in band o We cannot use late trophozoite form because sometimes it may also occur − Paroxysm occurs every 72 hours in P. ovale but it is larger − Cytoplasmic granules: Ziemman’s dots − Cytoplasmic granules is called James Dot Mature Schizonts o Reddish granules but larger and − Contains 6-12 merozoites arranged around darker compared to Schüffner's dots central pigment (“ Rosette” or “Daisy Head” o If wala sa choices and James dot, or Fruit pie”) you could use Schüffner's dots Mature schizonts Plasmodium malariae: − Contains 8 merozoites Blood Stage Parasites: Thin Blood Smears ✓ Fig. 1: Normal red cell; Plasmodium ovale: ✓ Figs. 2-5: Young trophozoites (rings); Blood Stage Parasites: Thin Blood Smears ✓ Figs. 6-13: Trophozoites; ✓ Fig. 1: Normal red cell; ✓ Figs. 14-22: Schizonts; ✓ Figs. 2-5: Young trophozoites (Rings); ✓ Fig. 23: Developing gametocyte; ✓ Figs. 6-15: Trophozoites; ✓ Fig. 24: Macrogametocyte ✓ Figs. 16-23: Schizonts; ✓ Fig. 25: Microgametocyte ✓ Fig.24: Macrogametocytes  ✓ Fig. 25: Microgametocyte ✓ Pigment: shows James dots. ✓ Aside from changes of size, it is more evident the changes of shape ✓ It becomes ovoidal and best seen in Fig 13 ✓ Distorted cell wall of RBC is called fimbriated RBC Babesia microti − Babesia microti infection, Giemsa-stained thin smear. − The organisms resemble Plasmodium falciparum; however Babesia parasites present several distinguishing features: They Plasmodium knowlesi vary more in shape and in size; and they do − Most recent discover but not commonly not produce pigment. isolated − Found in (example deer) usual definitive − Formerly classified as parasite infecting host monkey until they found out that it is capable − Man infected by : in infecting human o Bite of intermediate host (tick- − A primate malarial parasite common in ixodes) Southeast Asia (SEA) o Blood transfusion − Causes malaria in long tailed macaques − Signs and Pathology: (Macaca fascicularis) 1. Headache and fever − May also infect humans 2. Hemolytic anemia with hemoglobinuria in − The appearance of P. knowlesi is similar to immunocompetent host that of P. malariae. o But sometimes it may also resemblesP. falciparum Geographic Distribution: − PCR assay and molecular − Worldwide, but little is known about the characterization are the most reliable prevalence of Babesia in malaria-endemic methods for detecting and diagnosing P. countries, where misidentification as knowlesi infection Plasmodium probably occurs. − *however, P. vivax appears to interfere PCR testing (cross-reactivity) o Disadvantage of PCR is cross reactivity of P. vivax thus it is hard to identify even in molecular procedures (if we target DNA) COCCIDIAN PARASITES ✓ ingestion of oocyst (contains 2 sporocyst Coccidian parasites with 4 sporozoites each) − Largest group of apicomplexan protozoa ✓ Disease is common to children and male − The members are spore forming and homosexuals with AIDS considered as obligate intracellular parasite − Class: Sporozoea − Phylum: Apicomplexa − In class Sporozoea, the life cycle is Life cycle notes: characterized by an alternations of generation Three sequential stages: 1. Sexual: Sporogony − Producing oocyst 2. Asexual: Schizogony/ Merogony − Producing the merozoite 3. Gametogony − Results of male microgametocytes and female macrogametocytes From book for reference ng terms: ✓ The developing morphologic form within ✓ Once ingested of sporulated oocyst via the oocyst, known as a sporoblast. contaminated food and water, sporozoites exist ✓ Each sporoblast continues to mature and in small intestine releasing sporozoites(?) and eventually becomes a sporocyst. penetrate the cells. Medically important: ✓ The sporozoites develops to schizonts which ✓ Isospora belli ruptures host cell liberating merozoites ✓ Cryptosporidium hominis ✓ Merozoites infest new epithelial cells and some ✓ Cyclospora cayetanensis undergo gametogony to produce macro and ✓ Toxoplasma gondii microgametocytes that fused forming ✓ Sarcocystis hominis and Sarcocystis unsporulated oocyst. Therefore, sporulation suihominis occurs after passage of oocyst with the stool 1. Isospora belli Additional info: Morphology ✓ It has now been determined that I. belli is the − Infective stage: oocyst only known coccidial parasite that does not o “The infective stage is Sporulated have intermediate hosts. Humans serve as the Oocyst definitive host, in whom both sexual and − Is thin(stained?)wall, transparent and ovoidal asexual reproduction take place. − Contains two sporocyst − Each sporocyst contains four sporozoites From CDC: − Disease Associated: Isosporiasis 1. At time of excretion, the immature oocyst Mode of transmission: contains usually one sporoblast (more rarely two). 2. In further maturation after excretion, the ✓ Thorough washing and cooking of food sporoblast divides in two (the oocyst now ✓ Provision for safe drinking water contains two sporoblasts); the sporoblasts secrete a cyst wall, thus becoming sporocysts; and the sporocysts divide twice to produce four 2. Cryptosporidium hominis sporozoites each Morphology 3. Infection occurs by ingestion of sporocysts- − Infective stage: oocyst containing oocysts: the sporocysts excyst in the − Oocyst are rounded in shape and in a closer small intestine and release their sporozoites, view, each oocyst contains four sporozoites which invade the epithelial cells and initiate − Waterborne transmission is the most schizogony. common source 4. Upon rupture of the schizonts, the merozoites − Disease associated: Cryptosporidiosis are released, invade new epithelial cells, and continue the cycle of asexual multiplication 5. Trophozoites develop into schizonts which contain multiple merozoites. After a minimum of one week, the sexual stage begins with the development of male and female gametocytes Life cycle notes: 6. Fertilization results in the development of oocysts that are excreted in the stool. Pathology − Infection is usually asymptomatic among immunocompetent individual − Symptomatic: diarrhea, weight loss, eosinophilia, fever, malaise, abdominal pain and flatulence − In AIDS patients, reports on dissemination of parasite to other organs are present. Diagnosis − Detected in stool 1. Direct microscopy 2. Concentration technique (FECT, ZnSO4 and sugar floatation) 3. Staining techniques (Iodine, Kinyoun, ✓ The thin-wall oocyst results in autoinfection Auramine-Rhodamine) ✓ The thick-wall oocyst passed out in feces that ▪ “Transparent appearance if used may contaminated food and water,once ingested 4. Enterotest and duodenal aspirate it attaches to GI tract 5. Molecular testing ✓ These sporozoites develops in trophozoites and Treatment become intracellular ✓ Asymptomatic: bland diet and bed rest ✓ The trophozoites divides producing merozoites ✓ Symptomatic: Trimetroprim that infect other cells Sulfamethoxazole ✓ Macro and microgametocytes are eventually Prevention and control produced after fertilization and result formation ✓ Good sanitary practices of oocyst. From CDC: − AIDS patient: severe form of diarrhea, 1. Sporulated oocysts, containing 4 sporozoites, progressively worse and life-threatening are excreted by the infected host through − There could also be respiratory infection feces (and possibly other routes such as that could lead to chronic coughing, dyspnea respiratory secretions). and pneumonia. 2. Transmission of Cryptosporidium spp. occurs Diagnosis mainly through ingestion of fecally − For malin eater concentration technique contaminated water (e.g., drinking or In the recovery of oocyst in the stool recreational water) or food (e.g., raw milk) or 1. Sheather’s sugar floatation or FECT following direct contact with infected animals or 2. Kinyoun’s modified acid-fast stain people. ▪ Routinely used 3. Following ingestion (and possibly inhalation) ▪ oocyst appear as red-pink by a suitable host, excystation occurs. The doughnut-shaped circular sporozoites are released and parasitize the organisms in blue background epithelial cells of the gastrointestinal tract (and ▪ cheapest and simplest method of possibly the respiratory tract). diagnosis 4. In these cells, usually within the brush border, 3. IFA the parasites undergo asexual multiplication 4. Enzyme immunoassay (schizogony or merogony) and then sexual 5. DNA probe multiplication (gametogony) producing Treatment microgamonts (male) and macrogamonts ✓ No acceptable treatment yet (female). ✓ Nitazoxanide → said to be effective in 5. Upon fertilization of the macrogamonts by the preliminary studies microgametes that rupture from the ✓ Bovine colostrum, paromycin and microgamont, oocysts develop and sporulate in clarithromycin→treatment of severe the infected host. diarrhea 6. Zygotes give rise to two different types of ✓ Chemotherapy, body fluid replacement and oocysts (thick-walled and thin-walled). symptomatic treatment are recommended in 7. Thick-walled oocysts are excreted from the both immunocompetent and host into the environment , whereas thin-walled immunocompromised. oocysts are involved in the internal autoinfective Prevention and control cycle and are not recovered from stools. ✓ Chlorination is NOT effective 8. Oocysts are infectious upon excretion, thus ✓ Synergistic effect use of multiple disinfectant enabling direct and immediate fecal-oral and combined water treatment process may transmission. reduce C. hominis in drinking water ✓ Proper disposal of human and animal Pathology excreta − Immunocompetent: self-limiting diarrhea within 2-3 weeks 3. Cyclospora cayetanensis − Immunocompromised: severe diarrhea, Morphology bile duct and gallbladder maybe heavily − Originally called cyanobacterium like body infected, blunted intestinal villi, varying because of its photosynthesizing organelles degrees of malabsorption land excessive − Infective stage: oocyst fluid loss − Disease is usually self-limiting − MOT: ingestion  3.. The sporulated oocysts can contaminate fresh produce and water which are then ingested. 4. The oocysts excyst in the gastrointestinal tract, freeing the sporozoites, which invade the epithelial cells of the small intestine. 5. Inside the cells they undergo asexual Life cycle notes: multiplication into type I and type II meronts. 6. Merozoites from type I meronts likely remain in the asexual cycle, while merozoites from type II meronts undergo sexual development into macrogametocytes and microgametocytes upon invasion of another host cell. 7. Fertilization occurs, and the zygote develops to an oocyst which is released from the host cell and shed in the stool. Pathology − Initial symptoms include: malae, low grade fever, which may occur 12-24 hours after exposure. − The infection is in the form of gastrointestinal disturbances − Chronic and intermittent watery diarrhea occurs in early infection ✓ It begins with ingestion of sporulated oocyst − Fatigue, anorexia, weight loss, nausea, which contains two sporocyst with two abdominal pain, flatulence, bloating and sporozoites each. dyspnea may develop. ✓ Multiple fission of sporozoites takes place − Infections are usually self-limiting and inside the cell to produce meronts. Some of this immunity may result with repeated infection merozoites develops male and female − D-Xylose malabsorption has been found to gametocytes and their union results of oocyst develop which is passed out in feces. − No death is associated ✓ The oocyst undergoes complete sporulation Diagnosis within 7-12 days in warm environment. 1. DFS From CDC: 2. Concentration techniques 1. When freshly passed in stools, the oocyst is not 3. Kinyoun stain infective (thus, direct fecal-oral transmission 4. Fluorescent microscopy cannot occur; this differentiates Cyclospora from 5. Safranin staining another important coccidian 6. PCR parasite, Cryptosporidium). Note: fluorescence microscopy is used for screening 2. In the environment , sporulation occurs after cases of infection and oocyst are auto fluorescent days or weeks at temperatures between 22°C to that appear as blue or green circles 32°C, resulting in division of the sporont into Treatment two sporocysts, each containing two elongate ✓ Self limiting and No treatment needed if sporozoites mild  ✓ If pharmacologic treatment is warranted, ✓ The merozoite differentiate into gametocytes in Cotrimoxazole is given the intestinal epithelium of cats which result to Prevention and control the formation of oocyst. ✓ since the direct source is unknown, good ✓ The thinned walled ovoidal oocyst are passed sanitary practices should be followed out with feces of cats in unsporulated form ✓ Access to safe and clean drinking water ✓ The oocyst complete sporulation for 3-4 days ✓ Proper food preparation and can be ingested in contaminated food and water. ✓ The mature oocyst contains 2 sporocyst with 4 4. Toxoplasma gondii sporozoites each. Morphology ✓ When the mature oocyst reaches to the intestine − infective stages: tachyzoite, bradyzoite and of new host, it excyst releasing sporozoites. the oocyst ✓ The parasite gain entry to the lymphatic and − Definitive host: Cats spread to different organ tissue − Complete life cycle occurs in cats ✓ Following entry of sporozoites to a new cell, it − Clinical manifestation is apparent if immune transforms to tachyzoites system is suppressed → AIDS patient ✓ Tachyzoites are found during initial and acute − The mature oocyst contains 2 sporocyst stage of infection with 4 sporozoites each. ✓ This fast-multiplying tachyzoites give rise to bradyzoite eventually forming a cyst − Only tachyzoites and bradyzoites are found ✓ It is possible to transfer Tachyzoites from one in human and other animals intermediate person to another via blood transfusion and host. infected mother to fetus during first trimester of pregnancy. ✓ Tachyzoites can be transferred via organ transplant specially bone marrow ✓ Bradyzoites can be acquired by eating meats of Life cycle: infected animals From CDC: 1. Unsporulated oocysts are shed in the cat’s feces. Although oocysts are usually only shed for 1–3 weeks, large numbers may be shed. Oocysts take 1–5 days to sporulate in the environment and become infective. 2. Intermediate hosts in nature (including birds and rodents) become infected after ingesting soil, water or plant material contaminated with oocysts. 3. Oocysts transform into tachyzoites shortly after ✓ Life cycle is same with typical coccidian ingestion. These tachyzoites localize in neural consisting gametogony, schizogony and and muscle tissue and develop into tissue cyst sporogony in intestinal epithelium. bradyzoites. ✓ The extraintestinal stages are tachyzoite and 4. Cats become infected after consuming bradyzoites. intermediate hosts harboring tissue cysts. Cats  may also become infected directly by ingestion 1. Biopsy→ stained through hematoxylin and of sporulated oocysts. eosin stain 5. Animals bred for human consumption and wild ▪ Tissue section may be process and game may also become infected with tissue cysts stained using hematoxylin and after ingestion of sporulated oocysts in the eosin environment. 2. Serodiagnostic methods→ positive titer or 6. Humans can become infected by any of several a four-fold rise in the titer routes: 3. Sabin-Feldman methylene blue dye test → o Eating undercooked meat of animals very specific and sensitive IHAT harboring tissue cysts. 4. ELISA o Consuming food or water contaminated 5. PCR used when small amount of specimen with cat feces or by contaminated is available environmental samples (such as fecal- ▪ Detect antibodies against T. gondii contaminated soil or changing the litter ▪ Differentiating preexisting box of a pet cat). antibodies from possibly o Blood transfusion or organ transferred antibody from mother/ transplantation. antibodies related to illness is o Transplacentally from mother to fetus. important in assessing serological 7. In the human host, the parasites form tissue result cysts, most commonly in skeletal muscle, Treatment myocardium, brain, and eyes; these cysts may ✓ Pyrimethamine and sulfadiazine remain throughout the life of the host. Diagnosis o Only used for control, they do not is usually achieved by serology, although tissue kill T. gondii cysts may be observed in stained biopsy Prevention and control specimens ✓ Good sanitation and hygiene 8. Diagnosis of congenital infections can be ✓ Proper food preparation achieved by detecting T. gondii DNA in ✓ Protect food from cat feces amniotic fluid using molecular methods such as ✓ Meat should be properly cooked PCR Pathology 5. Sarcocystis hominis & Sarcocystis suihominis − Toxoplasmosis commonly asymptomatic, if − S. hominis from cattle immune system is good − S. suihominis from pigs − Encephalitis→most common manifestation − Definitive host: humans for immunocompromised patients − Infective form: mature oocyst/sporocyst − Myocarditis and pneumonia have also been which is ovoidal and contains two sporocyst reported with four sausage shape sporozoites − Cyst can be found in brain, skeletal and − Double layered, clear and colorless shell heart muscles as well as retina. surround the sporocyst − Stillbirth and abortion may result when mother acquired the infection during first trimester of pregnancy. − Babies may exhibit chorioretinitis, jaundice, seizure and hydrocephaly Diagnosis Life cycle:  4. Merozoites derived from the first-generation invade small capillaries and blood vessels, becoming second-generation schizonts. The second generation merozoites invade muscle cells and develop into sarcocysts containing bradyzoites, which are the infective stage for the definitive host 5. Humans become infected when they eat undercooked meat containing these sarcocysts. 6. Bradyzoites are released from ruptured cysts in the small intestine and invade the lamina propria of the intestinal epithelium. 7. There, they differentiate into macro- and microgametocytes. 8. Fusion of male and female gametes results in the formation of oocysts. 9. Oocysts sporulate in the intestinal epithelium and are shed from the host in feces. 10. Due to the fragile nature of the oocyst wall, individual sporocysts may also be detected in feces. Pathology ✓ First transmission route in human takes place ✓ Disease associated: Sarcosporidiosis and when the uncooked pig or cattle meat is ingested sarcocystosis ✓ Gametogony occurs in human intestinal cells ✓ Gastroenteritis, diarrhea, myalgia, weakness, the development of oocyst and released of fever sporocyst follows. ✓ For intermediate host, brain, muscle and ✓ The second transmission route occur when kidney tissues maybe damaged human accidentally shallow oocyst from stool ✓ May cause abortion to cows sources of animals the oocyst takes in ✓ Intestinal form is always noted such as precedence in human straited muscle nausea, diarrhea, and abdominal pain. ✓ Identification of sporocyst in feces requires From CDC: several stool examination done in separate 1. Both sporulated oocysts (containing two days sporocysts) and individual sporocysts can be passed in stool. Diagnosis 2. Sporocysts contain four sporozoites and a − Definitive: biopsy of an infected muscle refractile residual body. Sporocysts ingested by 1. Fecal floatation methods→ sporocysts will the intermediate host (cattle for S. hominis and be seen pigs for S. suihominis) rupture, releasing 2. Necropsy→ schizonts will be seen sporozoites. 3. Western blot 3. Sporozoites enter endothelial cells of blood 4. Serologic tests (IFA, ELISA) vessels and undergo schizogony, resulting in 5. PCR first-generation schizonts. Treatment ✓ No effective treatment is known  ✓ Corticosteroids were found to be useful in muscular inflammation ✓ Trimethoprim-sulfamethoxazole →seen as potentially effective in treating intestinal infections Prevention and control ✓ Uncooked animal carcass should not be fed to other animals ✓ Proper care and disposal of animal stool