Para 311 Midterms Lecture Reviewer PDF

**PARA 311 MIDTERMS LECT REVIEWER** *[BLOOD AND TISSUE FLAGELLATES ]* - "These are the parasites that inhabit the tissue and the blood of human with the aid of vector. - Vector transmitted disease - Primary mode of transmission: Insect bite **[Family: Trypanosomatidae]** **Genus:**...

**PARA 311 MIDTERMS LECT REVIEWER** *[BLOOD AND TISSUE FLAGELLATES ]* - "These are the parasites that inhabit the tissue and the blood of human with the aid of vector. - Vector transmitted disease - Primary mode of transmission: Insect bite **[Family: Trypanosomatidae]** **Genus:** A. Trypanosoma gambiense B. Leishmania tropica C. Leptomonas D. Herpetomonas E. Phytomonas 1. **Fusiform body →** except for rounded or ovoidal 2. **Nucleus location varies →** depending on the form 3. **Single flagellum →** arises anteriorly, spiral wave movement 4. **Kinetoplast (collective term)** **→** an accessory body found in many protozoa, primarily the Mastigophora; it contains DNA and replicates independently - **Parabasal body** **→** a structure near the nucleus in certain parasitic flagellates. "Cytoplasmic structure that supports the nuclear functions. - **Blepharoplast** **→** a basal body in certain flagellated protozoans that consists of a minute mass of chromatin embedded in the cytoplasm at the base of the flagellum. **"**Serve as the site for growth of the **Axoneme.** 5. **Axoneme** **→** found at inner portion. **"**Flagellum arises from this "Basis for identification and significant in one form of hemoflagellates: Location/ position of nucleus and Kinetoplast. 4. **[Stages/Morphologic Form of Development: ]** - Amastigote (rounded or ovoidal) - Promastigote - Epimastigote - Trypomastigote "Not all are routinely recovered from human specimen 1. **Amastigote Stage (Leishmania)** - Ovoidal shaped - "This is the only form who is exempted in the fusiform because it appears to be **Ovoid / rounded** **bodies without flagella** - Single nucleus with karyosome - "Located off center - Parabasal body - "Located adjacent to the blepharoplast - Blepharoplast - "Dot like and not visible - "Attached to the axoneme - Axoneme - Non-flagellated stage - 2 -- 3 um - Found intracellularly in monocytes, endothelial cells - Presence of large nucleus - Axoneme arises from kinetoplast and extend to anterior tip - "Kinetoplast is located anterior to the nucleus - Diagnostic form for Leishmania - **Routinely recovered** from human specimen (Pathogenic) - **Diagnostic form:** - Shape; Rounded or ovoidal - Absence of external flagellum 2. **Promastigote (Leptomonas)** - Spindle -- shaped body - **Presence single free flagellum** arising from kinetoplast at anterior end - 15 -- 20 um 1.5 -- 3.5 u - No undulating membrane - Diagnostic form for Leptomonas - "Leptomonas infects the gastrointestinal tract of vector - Not routinely recovered (culture) - **Diagnostic form:** - Absence of undulating membrane 3. **Epimastigote (Crithidia)** - Spindle-shaped, longer, wider compared to promastigote - Single nucleus with karyosome - "Single nucleus is directed towards the base. - "Anteriorly located kinetoplast - Single flagellum anteriorly located - Parabasal body - Blepharoplast - Axoneme → Flagellum - Undulating membrane along the course flagellum - Diagnostic form for Crithidia - "Crithidia would only be infecting the vector - **Diagnostic form:** - presence of undulating membrane (extends half of the total body length)  4. **Trypomastigote (Trypanosoma)** - Nucleus located anterior to Kinetoplast - Full body length undulating membrane - "Diagnostic form for Trypanosoma - Routinely recovered in humans - Spiral-shaped - "In blood film, it is twisted in C, U, S) - Central nucleus - Single flagellum - Diagnostic form: - Posterior kinetoplast - Full body length undulating membrane **[Genus Leishmania]** - 3 species recognized according to clinical entitiesNew World Leishmaniasis - **Morph:** resembles L. tropica - **Amastigote is recovered in human sample** - **Habitat:** tissue cell, endothelial cell, monocyte, mucous membrane, nose mouth & pharynx - not found peripheral blood - rarely localized in visceral organ - **Life Cycle:** some w/ L. tropica - **Insect vector** -- Sandfly 1. Lutzomyia 2. Psychodopygus **[Pathology and Symptoms]** - start as papule → ulcer - invasion of tissue accepted w/ rapid necrosis → deep, eroding, fungating & infiltrating ulcer - "Aside from mucous membrane of nose and mouth, the surrounding soft part of the face may be infected which could lead to disfigurement of the face due to edema, mucosal lesion and secondary lesion. **[Diagnostic]** 1. Smear from ulcer → demonstrate amastigote stage - Same with L. tropica 2. Serology -- CFT (Complement fixation test) 3. Culture -- Nubin, Nichol, Mc Neil **[Treatment/Therapy]** 1. Berberine sulfate 2. Fuadin - **Leishmania donovani** - Visceral form of leishmania affects the **Visceral organs** - **Geographical Dist.:** Worldwide -- India, Asia, Southern, Russia, Northern China, East Africa, all countries bordering Mediterranean - **Disease:** **Kala-azar** / Visceral L., Death fever/ tropical splenomegaly/ Dum dum fever - **Kala-azar and Dum dum fever is the most popular term used** - Some/ may be recovered with other leishmania species - Coinfection may occur - Same patient, different species - Main focus of infection → Visceral organ - Visceral leishmaniasis (Kala-azar) is caused by parasites of the genus Leishmania, subgenus Leishmania, **complex donovani** (donovani, infantum, chagasi species) - **Habitat:** - Endothelial cells of visceral organ, Spleen liver, Intestinal mucosa, Mesenteric glands - "Main clinical presentation is **Hepatosplenomegaly** enlargement of the spleen and liver. - Also gastrointestinal distress because of habitat intestinal - It has the ability to migrate via bloodstream/systemic disease - **Mode of Transmission:** bite of **Sandfly** - **Vector:** 1. Phlebotomus argentipis 2. P. chinensis 3. Lutzomyia - **Same with Leishmania brasiliensis** **[Pathology and Symptoms]** - Papule formation at site of bite → bloodstream → engulf by macrophages & endothelial cells - 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 **[Treatment/Therapy]** - Potassium antimony tartrate - Antimony tartrate - Neostibosan - Hydroxy stilbamidine - Isethionate "Leishmaniasis is less severe compared to trypanosomiasis (nagagamot) "Vector of Leishmaniasis is not found in the Philippines. The cases that was found had travel history. **[Genus Trypanosoma ]** **Morph:** - Elongated spindle -- shaped body w/ more or less rounded posterior end & Tapering anterior end - Parabasal body - Axoneme Blepharoplast - single flagellum arising from blepharoplast & runs anterior to form the margin of undulating membrane - oval nucleus at center w/ central karyosome **[Mode of Transmission]** 1. Bite blood-sucking invertebrate 1. **Glossina flies (Tsetse)** →*gambiense, rhodesiense* 2. **Reduviid bug** → *cruzi* 2. Ingestion infected feces of intermediate host by definitive host (only applicable to Reduviid bug) 3. Entrance / inoculation of parasite through abrasion / break skin **[Life Cycle of Brucie Complex: ]** **Transmission: Bite of tsetse fly** - **Starting form: Metacyclic trypomastigotes** →**Which infecting the salivary gland** - **Multiples in blood, lymph and spinal fluid.** - **Invaded in the bloodstream: Bloodstream Trypomastigote** → **second form** - **Procyclic trypomastigote** → **third form present in midgut** - **Epimastigote** → **multiple and migrate in salivary gland** - **Infective form: Metacyclic trypomastigote** **"Like a fly but has characteristic of mosquito** ***[Based on CDC:]*** **During a blood meal on the mammalian host, an infected tsetse fly (genus *Glossina*) injects metacyclic trypomastigotes into skin tissue.** 1. **The parasites enter the lymphatic system and pass into the bloodstream ** 2. **Inside the host, they transform into bloodstream trypomastigotes ** 3. **are carried to other sites throughout the body, reach other body fluids (e.g., lymph, spinal fluid), and continue the replication by binary fission ** **In the fly's midgut, the parasites transform into procyclic trypomastigotes, multiply by binary fission(6) , leave the midgut, and transform into epimastigotes (7) . The epimastigotes reach the fly's salivary glands and continue multiplication by binary fission (8) . The cycle in the fly takes approximately 3 weeks. Rarely, *T. b. gambiense *may be acquired congenitally if the mother is infected during pregnancy.** **[Species of Medical Importance]** 1. *Trypanosoma cruzi* 2. *Trypanosoma gambiense* 3. *Trypanosoma rhodesiense* - **Trypanosoma cruzi** - **Synonym:** Schozitrypanum cruzi, Trypanosoma escomele, Trypanosoma triatomae - **Popular name ang gamitin** - **Disease:** - South American Trypanosomiasis - (Sleeping sickness) → brain is the infection site. (**Somnolence)** - **Stages of sleeping sickness** - **Hemolymphatic →** first stage: Blood and Lymph - **Meningoencephalitis →second stage:** causes swelling and damage to brain - **(Chagas disease)**  - **Geographical Dist.:** Central & South America - ***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 - ***T. cruzi***: the disease is a public health threat in most Latin American countries, although cases due to blood derivatives or blood transfusion has been reported in non-endemic regions. **[Clinical Features ]** - The **acute phase** is usually asymptomatic, but can present with manifestations that include **fever, anorexia, lymphadenopathy, mild hepatosplenomegaly, and myocarditis** - **Romaña\'s sign** may appear as a result of conjunctival contamination with the vector\'s feces**. (ocular)** - A **nodular lesion or furuncle**, usually called **chagoma**, can appear at the site of inoculation/ bite site. (elevated lump) - **Chronic Chagas disease** and its complications **can be fatal.** **[Mode of Transmission]** 1. Bite of Reduviid bug which defecate at site of inoculation 2. Accidental ingestion of bug 3. Blood transfusion 4. Sexual intercourse, vertical transmission (studies say/possible?) **Intermediate host** → Reduviid bug **Scientific name:** 1. Panstrongylus megistus 2. Triatoma infestans 3. Rhodnius prolixus **[Life Cycle of Trypanosoma cruzi:]** - **Bite of reduviid bug, it would defecate containing trypomastigote. (Starting form: Metacyclic trypomastigotes)** - **Hind gut where Metacyclic trypomastigotes is found.** - **Second form: Amastigote form** **Arrows nanakahiwalay sa main: there would be several cycles involving trypomastigote and amastigote forms. (It would go back and so on)** - **Third form: Bloodstream trypomastigote** - **Fourth form: epimastigote** → **present in midgut** - **Five: Metacyclic trypomastigotes and migrates to the hindgut** ***[Based on CDC:]*** **An infected triatomine insect vector (or "kissing" bug) takes a blood meal and releases trypomastigotes in its feces near the site of the bite wound.** 1. **Trypomastigotes enter the host through the bite wound or intact mucosal membranes, such as the conjunctiva .** 2. **Inside the host, the trypomastigotes invade cells near the site of inoculation, where they differentiate into intracellular amastigotes ** 3. ** .The amastigotes multiply by binary fission ** 4. ** and differentiate into trypomastigotes, and then are released into the circulation as bloodstream trypomastigotes.** 5. **Trypomastigotes infect cells from a variety of tissues and transform into intracellular amastigotes in new infection sites. Clinical manifestations can result from this infective cycle. The bloodstream trypomastigotes do not replicate (different from the African trypanosomes). Replication resumes only when the parasites enter another cell or are ingested by another vector. The "kissing" bug becomes infected by feeding on human or animal blood that contains circulating parasites ** 6. ** The ingested trypomastigotes transform into epimastigotes in the vector's midgut.** 7. **The parasites multiply and differentiate in the midgut ** 8. ** and differentiate into infective metacyclic trypomastigotes in the hindgut  ** **. Other less common routes of transmission include blood transfusions, organ transplantation, transplacental transmission, and foodborne transmission (via food/drink contaminated with the vector and/or its feces).** **[Pathogenesis / Pathology & Symptoms]** - disease manifested as painful chancre at site of inoculation → [Chagoma] → ulcerate → bloodstream → throughout body - Inc. pd. 7-14 days - High fever, edema, Romañas sign CNS manif. → encephalitis - Heart -- myocarditis - Lympadenopathy - Splenomegaly - Hepatomegaly **[Diagnostic]** 1. Microscopic demonstration of parasite stained blood smear / lymph node aspirate 2. Culture NNN med. (Nubin-Nichol-Mc Neil) 3. Serological: CF, DAT, IHT In CSF, detection of IgM in serum and elevate serum proteins: Diagnostic for Chagas disease **[Prognosis]** - Bad if CNS & Heart involved in cases of chagas disease **[Treatment]** - Primaquine = partially effective - Nifurtimox = acute cases - There is no entirely available drug for treatment/ prevention of the disease - Crucial diagnosis and treatment especially in Hemolymphatic stage - **Trypanosoma gambiense** - **Geographical Dist.:** Central & West Coast of Africa - **Disease:** - Gambian Sleeping Sickness - West African trypanosomiasis - **Vector:** Tse-Tse fly -- Glossina sp. 1. Glossina palpalis 2. Glossina techinoides **[Morphology]** - Spindle -- shaped - 14-33 u X 1.5-3.5 u - Nucleus centrally located - Kinetoplast found posterior end of the body - Undulating membrane originating Blepharoplast - Anterior flagellum runs along the edge of undulating membrane - Volutin granules cytoplasm (dark blue) **[2 stages of development]** 1. Trypomastigote → vertebrate host 2. Epimastigote → Invertebrate host **[Habitat:]** - Blood - LN - CSF - Connective tissue - Intracellular space brain - Lymph channels throughout body **[Pathogenesis]** - **Primary lesion Painful chancre** at the bite site, fever, malaise headache - **Other signs that manifest:** - **Winterbottom's sign** **→** enlargement of cervical lymph nodes (hemolymphatic stage) - **Kerandel's sign** **→** delayed pain (meningoencephalitis stage) - Typically, disease progresses from acute stage w/ trypanosome multiplying in the blood & lymphatic → to a sleeping sickness stage with invasion CNS & terminates fatally - CNS = tremors, character changes, somnolence, coma - Death results either from the disease or from intercurrent infection **[Prognosis]** - Favorable if Rx instituted before involvement of the CNS. **[Diagnostic]** 1. Microscopic examination smear from lymph, blood & CSF 2. Detect anti-trypanosome AB A. Immunofluorescence test B. Indirect hemagglutination test **[Treatment]** - Pentamidine & Suramin (very effective if given during blood - lymphatic stage) - Tryparsamide 2-3 grams 15-20 weeks - Metarsoprol **→** for late stage with CNS involvement - **Trypanosoma rhodesiense** - **Geographical Dist.:** East Africa - **Disease:** - East African Sleeping Sickness - Rhodesian Sleeping Sickness - **Morph, Pathogenesis, Life cycle** = resembles T. gambiense - **Symptomatology:** - more severe manifestation than T. gambiense - course rapid - death early if CNS is involved fever, myalgia, rigor, lethargy, mental disturbance **[Prevention: ]** 1. Reduction of contact w/ Tse-Tse flies through control measures against them. (traps, screen, insecticide) 2. Reduction of human infection by diagnosis & treatment of infected person - **Trypanosoma brucei** - Thin blood smear stained with Giemsa. - Typical trypomastigote stages (the only stages found in patients), with a posterior kinetoplast, a centrally located nucleus, an undulating membrane, and an anterior flagellum. - The two Trypanosoma brucei species that cause human trypanosomiasis, T. b. gambiense and T. b. rhodesiense, are undistinguishable morphologically. **[Clinical Features]** - Infection occurs in 2 stages. A trypanosomal chancre can develop on the site of 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\ (Plasmodium)**  Malaria parasite belongs to **Phylum:** Apicomplexa **Class:** Sporozoa **Order:** Haemosporida **Genus:** Plasmodium The rest listed in apicomplexa are classified as Coccidia except for **Plasmodium** and **Babesia** which are classified as Haematozoa **Plasmodium** - A name which means nucleated mass and in which the asexual cycle (schizogony) takes place in the red blood cells of vertebrates and the sexual cycle (sporogony) in mosquitoes. - "Causative agent for malaria (mal: bad, aria: air) - It was based on transmission and they thought that it is via air borne transmission later on they found out that is vector borne - **Transmission:** Bite of mosquito - **Vector:** Anopheles mosquito **[4 Species of Plasmodium]** 1.  Plasmodium falciparum →Welch 1922 2. Plasmodium vivax → Grassi and Feletti 1980 3. Plasmodium malariae →Laveran 1881 4. Plasmodium ovale → Stephens 1922 "There are more 100 species, but this 4 are only the 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 or sexual stages, which are differentiated by compact cytoplasm and the absence of nuclear division **[STAGES OF DEVELOPMENT]** 1. **Trophozoite** - the earliest stage with 1 nucleus living inside the red cells. The early trophozoite is ring-shaped with a red chromatin dot and a small amount of blue cytoplasm when stained with [Giemsa or Wright's stain.] **[Two Types: ]** a. **Early Trophozoite (Ring form)** - Ringlike appearance of plasmodium - "When stained in Giemsa stain, it consists of blue **cytoplasmic circle** connected to chromatin red **chromatin dot** (which serves as nucleus). The space inside the ring/cytoplasm is known as **Vacuole**. - Sometimes the vacuoles are filled in which is sometimes basis in identifying some species. b. **Late Trophozoite (Developing trophozoite form)** - The **remnants of** cytoplasmic circle and chromatin dot are **still visible** - The **appearance varies** among plasmodium species - Some members serves this as diagnostic form.  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 - Not a basis for differentiation b. **Mature Schizonts** - Characterized by **fully developed stage** of **asexual trophozoite** known as **merozoites** - To identify species of plasmodium we observe the **numbe**r and **arrangement of merozoites** "Instead of immature schizonts for identification, we look for mature schizonts 3. **Gametocytes** - **sexual forms** with 1 large compact and round or elongated chromatin mass - **Pigment:** Some parasites have granules of pigment in their cytoplasm, other do not have any. **[Two Type: ]** a. **Microgametocytes** - It represents the male sexual form - Rounded/Roundish in shape - With exception of P. falciparum, which is crescent shaped - Large diffuse chromatin mass - Chromatin is **centric** b. **Macrogametocytes** - 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 **NOTE:** - **P.vivax** and **P.falciparum** are more common. - Plasmodium is a wide distribution in many **tropical** or **subtropical** regions of the world 1. **P. falciparum** - 1 or 2 red nuclei on the ring-like light blue cytoplasm; multiple infection in a cell. - Consist of **more than 1** ring form inside RBC called **multiple infection** - infected RBC like normal RBCs. - P. falciparum: [only the early trophozoites and gametocytes can be seen in the peripheral blood,] - Consist of scanty cytoplasm connected to one (circle configuration) or two (called **headphone configuration**) small chromatin dots. - **Accole/ Applique form** is evident - Meaning the ring forms are directed near towards the edge of RBC - The cytoplasm of RBC may contain **Maurer's dots** - Appear to be red granules with **irregular to comma shaped** - **Diagnostic for P. falciparum**: Multiple infection - **Specimen of choice**: Blood - **Common recovered in P. falciparum:** Ring form and Gametocytes ***Note:*** In parasitic studies, Giemsa stain is recommended ***Question:*** How many RBC are seen in the picture? ***Answer:*** Only one "You can Identify the morphologic form inside the RBC **Developing Trophozoite** - Same appearance in ring form - Heavy cytoplasmic ring common - Cytoplasm is thicker - Fine pigment granules - Mature forms only seen in severe infections **Immature schizont** - Not useful for differentiation among members because all species has same appearance in immature schizont - Oval in shape, nucleus - Divided into 2-4 or more , - Malarial pigment begins to concentrate in a mass. - Characterized by multiple chromatin bodies - There are also cytoplasm observed (Maurer's Dot) **Mature schizont** - Nucleus divided into - Typically consist of 8-36 merozoite (**Average, 24);** and cytoplasm also divided, each nucleus surrounded by a portion of cytoplasm to form merozoites, malarial pigment clumped. - 24 ata isasagot if ever tinanong? - For proper Identification: look for number or arrangement of merozoites - These is where we can observed large amount of merozoites ***NOTE:*** **Gametocytes** in P. falciparum are bigger compared to total diameter of RBC **Male gametocyte** - Sausage in shape; 1 - loose nucleus in center of it ; malarial pigment - Diffuse - **Diagnostic:** Crescent shape - **Dispersed / scattered central chromatin** with nearby black pigment usually visible - To differentiate male and female gametocytes: look for the distribution of chromatin - **Chromatin bodies**: Dispersed **Female gametocyte** - Crescent in shape ; - 1 compact nucleus in center of it. - **Chromatin bodies:** Compact *[Based sa sinabi ni maam + book:]* **[Human Cycle (Schizogony)]** **Primary mode of transmission** - Bite of anopheles mosquito **Origin:** - Mosquito containing the infective form called (sporozoites) - **Sporozoite** present/infecting **salivary gland** - The sporozoite are transported to the peripheral blood until it reaches to liver and enter parenchymal cells (hepatocytes). - First stop of Sporozoite: **Liver cells (hepatocytes)** - After which, there would be stages of development that would take place **Schizogony (Schizogonic cycle)** - Terms used to describe the cycle from mosquito to after it enters to human host - Asexual reproduction **[Schizogony is divided into two cycle:]** 1. **Exoerythrocytic Cycle** - Outside red blood cells - First cycle involved in schizogony which takes place in **Liver cells.** - Stages of development would occur: It would start from trophozoites, schizont - One the **Schizonts**/ infected liver cells ruptures, it would release **merozoites** - 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** - A number of erythrocytic may occur - In the **second path**, some mature merozoites would develop into **gametocytes forms** - After this, it would go back to the body of vector **Mosquito Cycle (Sporogony)** - Gametocytes ingested by the mosquito **(sexual reproduction**) - There would be certain morphologic form that is transmitted back to the vector: **Gametocytes** - Once the mosquito bite the infected person, it would be ingesting the gametocytes - Soon the **male and female gametocytes would unite** in the mosquito's stomach and form a fertilized cell called **zygote** in the form of **ookinete**. - The ookinete would become encysted and matures into an **oocyst.** - The oocyst is the form that contains sporozoites. - On complete maturation, the oocyst ruptures and releases numerous **sporozoites** which migrate **into the salivary gland** of the mosquito and ready to infect another human. *[Based on CDC:]*  The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female  1. *Anopheles* mosquito inoculates **sporozoites** into the human host  2. Sporozoites infect **liver cells**  3.  and mature into **schizonts**  4. which rupture and release **merozoites ** (Of note, in *P. vivax* and *P. ovale* a dormant stage \[hypnozoites\] can persist in the liver and cause relapses by invading the bloodstream weeks, or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony The letter A), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). 5. Merozoites **infect red blood cells**  6. The ring stage trophozoites mature into schizonts, which rupture releasing merozoites  7. Some parasites differentiate into sexual erythrocytic stages **(gametocytes) **.Blood stage parasites are responsible for the clinical manifestations of the disease. 8. The **gametocytes,** male (microgametocytes) and female (macrogametocytes), are ingested by an *Anopheles* mosquito **during a blood meal**  The letter C. The parasites' multiplication in the mosquito is known as the sporogonic cycle  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:]** **tachysporozoite and bradysporozoite** - They are genetically distinct at the time of maturation when they enter the hepatic cells at the same time. **[Tachysporozoite]** - **Common** and present **originally in saliva** of mosquito - grow in the **hepatic cell** and multiply to form exoerythrocytic schizonts and then invade RBCs **[Bradysporozoite]** - is the cause of **relapse of malaria.** **(hypnozoites)** - malaria relapse: same person, same agent - Bradysporozoite stay in the hepatic cells and will multiply later. - Bradysporozoites are only produce by **Plasmodium Vivax** and **Plasmodium ovale.** **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.** - Part of **Sporogony** **[Characteristic of Life Cycle]** **Intermediate host:** human (asexual phase) **Definitive host/ Final host:** Mosquito (sexual phase) **Infective stage:** sporozoite **MOT:** female mosquito bite skin of human. **Parasitic position :** liver and [red blood cells] **Transmitted stage** : gametocytes **Sporozoite:** tachysporozite and bradysporozite **Pathogenicity** - **Main clinical feature of malaria**: Paroxysm (attack of malaria) - Paroxysm would start when red blood cell is infected by plasmodium ***Question:*** When does paroxysm occur? Schizogony → erythrocytic cycle In Exoerythrocytic, the patient is usually asymptomatic. **Mechanism** - liberation of merozoites and malarial pigment; RBC debris into the blood stream. **Symptoms/Signs (in a typical case)** - headache,lethargy, anorexia, nausea, vomiting, diarrhea, ischemia - **Ischemia** → loss of blood supply on organs because of blockage of capillaries (merozoites and other debris) **Paroxysm** shows a succession of **[3 stages:]** 1. The **cold stage (chill/** **rigor),** lasting for 30 min to 1 hr. 2. The **hot stage (fever),** 1 to 4 hrs. 3. **Sweating stage** 1 to 2 hrs. These stages happens in regular interval. We also take note of the periodicity which vary from one member to other. **[Characteristi]c** 1. periodic 2. repeated 3. regular A specific attack that it is up to months or even years after the primary attacks. - The **bradysporozoites** in the liver spend a rest and sleeping times of months or even 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** - Disease associated**: Malignant Tertian Malaria** - Patient may experience nausea, vomitting, and diarrhea aside from paroxysm - **Periodicity** of paroxysm occurs every **36 to 48 hours** - Malaria caused **by P.falciparum** is most severe than that caused by other plasmodia. - "It **affects all ages of Red blood cell** from young to mature RBC - About **50% of cells** may be infected - It may enter to the kidney, CNS or liver - The **serious complication of P.f**. - involves **cerebral malaria** (involving the brain) - **Kidney** involvement known as **blackwater fever** usually result massive **hemoglobinuria** (presence of hemoglobin) in which the urine becomes in color, because of acute hemolysis of RBC; - acute respiratory distress syndrome; severe gastrointestinal symptoms; shock and **renal failure** which may cause comatose/ death. - Thus, it is crucial to prompt diagnose and treatment **Laboratory Diagnosis** - laboratory diagnosis of malaria is confirmed by the demonstration of malarial parasites in **the blood film** under microscopic examination. - **Thin film** → to identify specific members - **Thick film**→ screening purposes (look for any suspicious form of plasmodium 1. **Microscopy (Gold Standard)** - "**Thick and Thin Blood Smear**" - stained with **Giemsa or Wright's stain** - perform **multiple sets of blood films** (blood collected **every 6 to 12 hours for up to 48 hours**) 2. **Serological test** - ELISA →detection of antibodies - **Rapid Diagnostic Test** (RDT) → detection of antigen using monoclonal antibodies **[Manner of Reporting]** A. **Qualitative** - \+ = 1-10 parasite/100 thick field - ++ = 11-100 parasite/100 thick field - +++ = 1-10 parasite/thick field - ++++ = more than 10/ thick field B. **Quantitative** **Treatment** - **Chloroquine and quinine**→ anti-erythrocytic stage drugs. - **Primaquine and pyrimethamine** → anti-exoerythrocytic stage drugs. ***Question:*** Which stage of plasmodium can these drugs kill? ***Answer:*** ***Question:*** Which set of drugs targeting more forms of plasmodium? ***Answer:*** Chloroquine and quinine because anti-erythrocytic **Prevention** - **Chemoprophylaxis** - **Chloroquine / pyrimethamine** - Endemic in the Philippines malaria: Palawan - used for prophylaxis of malaria - **Chemotherapy:** 1 week before entry into the endemic area; for 4 weeks after returning from the endemic area. **Mosquito Control** - Reconstruction of environment: eradicate the breeding places of mosquitoes. - Use insecticides - Use mosquito nets, screen, or mosquito repellants to protect the person from mosquito bites. ***Note:*** Aside from bite of mosquito, it could transmitted via: - blood transfusion → Transfusion Malaria - common in intravenous drug users via sharing of syringes →Mainline malaria - Transplacental → Congenital Malaria **Plasmodium falciparum, [ring form]** - Thin blood film, Giemsa stained - Early trophozoite- \"Ring form\" containing a reddish chromatin \"dot\" and blue cytoplasm \"ring\" - A ring may contain double chromatin - A picture showing **[Maurer\'s dots](http://www.medicine.cmu.ac.th/dept/parasite/proto/Pf_thin.jpg)** on red cell membrane  **Trophozoites** - *Plasmodium falciparum*:  - Early trophozoites & late trophozoites have the characteristic signet ring shape. - Also, unique to *P. falciparum* is the presence of multiple trophozoites in one cell.  - Picture shows: developing trophozoite (thicker cytoplasmic circle) **Plasmodium falciparum** - Philippines - Organisms invades all age of red cells - Malignant tertian malaria - Multiple parasitization of red cells "multiple ring" - Small ring forms (1/6 diameter red cell), double nuclear dots - Cresent-shaped gametocytes **Plasmodium falciparum:** Blood Stage Parasites: **Thin Blood Smears**  - Fig. 1: Normal red cell; - Figs. 2-18: Trophozoites - Figs. 2-10 correspond to ring-stage trophozoites); - Figs. 19-26: Schizonts (Fig. 26 is a ruptured schizont); - Figs. 27, 28: Mature macrogametocytes (female); - Figs. 29, 30: Mature microgametocytes (male)  - **Maurer's dot** can be seen - Most likely there wouldn't be changes in size of infected RBC in cases of P. falciparum (another clue)  **Plasmodium vivax** - Worldwide (widest among) - **Only reticulocyte** invaded (young RBC) - Single large ring succeeded by ameboid form in large red cell - round gametocyte - **Disease associated:** Benign tertian malaria - **Because flulike sysmptoms** - **Paroxysm would take place every 48 hours** - Early trophozoites resembles ring forms of P. falciparum - Multiple infection is not common in P. vivax **Diagnostic form: Late trophozoite** - It is irregular shape like ameboid form with pseudopodia; within cytoplasm, brown pigment granules ([malarial pigment]→ [hemozoin]) appear. - infected RBCs are pale in color,and have (fine red granules) - the remnants are still visible but it is not in the form of ring but rather ameboid form wherein the cytoplasm becomes irregular (not perfect circle) - Cytoplasmic granules are finer called **: Schüffner\'s dots** - **Diagnostic form**: ameboid form **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; - Figs. 19-27: Schizonts; - Figs. 28 and 29: Macrogametocytes - Fig. 30: Microgametocyte   - **Pigment: Schüffner\'s dots** can be seen - There is a changes of size (increase/enlargement occurs in infected RBC) - P. vivax and P. Ovale has the same feature - Cell distortion is possible but it is common more common in P. ovale  **Plasmodium malariae** - Single large compact ring or band forms - Invades old red cells (mature RBC) - Ovoid gametocyte - **Disease associated**: Quartan malaria - **Diagnostic form**: Late Trophozoite (in **band form** - Instead of ameboid form it is in **band form** - Paroxysm occurs **every 72 hours** - **Cytoplasmic granules: Ziemman's dots** **Mature Schizonts** - Contains 6-12 merozoites arranged around central pigment (" Rosette" or "Daisy Head" or Fruit pie") **Plasmodium malariae:** Blood Stage Parasites: **Thin Blood Smears** - Fig. 1: Normal red cell; - Figs. 2-5: Young trophozoites (rings); - Figs. 6-13: Trophozoites; - Figs. 14-22: Schizonts; - Fig. 23: Developing gametocyte; - Fig. 24: Macrogametocyte - Fig. 25: Microgametocyte - **Pigment: Ziemman's dots** - Hardly visible which appears fine/ dust like gray colored granules - No changes of size in infected RBC because it invades mature RBC **NOTE:** Figure 6-10 would show best the late trophozoite **Plasmodium ovale** - Single compact ring - Large pale red cells - Targets young rbc - Found in Africa - Disease associated: **Benign Tertian Malaria** - Ring form and gametocytes=P. vivax - To differentiate the two: Mature schizonts? - We cannot use late trophozoite because sometimes it may also occur in P. ovale but it is larger - Cytoplasmic granules is called **James Dot** - Reddish granules but larger and darker compared to Schüffner\'s dots - If wala sa choices and James dot, you could use Schüffner\'s dots **Mature schizonts** - Contains 8 merozoites **Plasmodium ovale:** Blood Stage Parasites: **Thin Blood Smears** - Fig. 1: Normal red cell; - Figs. 2-5: Young trophozoites (Rings); - Figs. 6-15: Trophozoites; - Figs. 16-23: Schizonts; - 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**  **Plasmodium knowlesi** - Most recent discover but not commonly isolated - Formerly classified as parasite infecting monkey until they found out that it is capable in infecting human - A primate malarial parasite common in Southeast Asia (SEA) - Causes malaria in long tailed macaques (*Macaca fascicularis*) - May also infect humans - The appearance of *P. knowlesi* is **similar to that of *P. malariae.*** - But sometimes it may also resemblesP. falciparum - **PCR assay and molecular characterization** are the most reliable methods for detecting and diagnosing *P. knowlesi* infection - *\***however, P. vivax appears to interfere PCR testing (cross-reactivity)*** - Disadvantage of PCR is cross reactivity of P. vivax thus it is hard to identify even in molecular procedures (if we target DNA) **Hindi to napresent?** **Babesia microti** - *Babesia microti* infection, Giemsa-stained thin smear.  - The organisms resemble *Plasmodium falciparum*; however *Babesia* parasites present several distinguishing features: They vary more in shape and in size; and they do not produce pigment.  - Found in (example deer) usual definitive host - **Man infected by :** - Bite of intermediate host (tick-ixodes) - Blood transfusion - **Signs and Pathology:** - Headache and fever - Hemolytic anemia with hemoglobinuria in immunocompetent host **Geographic Distribution:** - Worldwide, but little is known about the prevalence of *Babesia* in malaria-endemic countries, where misidentification as *Plasmodium* probably occurs.