Parasitology - Sporozoa (Plasmodium spp. and Babesia spp.) PDF

PARA311: CLINICAL PARASITOLOGY TOPIC: SPOROZOA [Plasmodium spp. and Babesia spp.] 1ST SEMESTER | S.Y 2024-2025 LECTURER: Prof. Rose Dyane Hizola, RMT, MPH TOPIC - Babesi...

PARA311: CLINICAL PARASITOLOGY TOPIC: SPOROZOA [Plasmodium spp. and Babesia spp.] 1ST SEMESTER | S.Y 2024-2025 LECTURER: Prof. Rose Dyane Hizola, RMT, MPH TOPIC - Babesia spp. SUBTOPIC o Babesia microti SUB SUBTOPIC o Babesia divergens o Babesia bovis - Cryptosporidium hominis Protozoan parasites are characterized by the production - Cyclospora cayetanesis of spores like oocysts [spore-like oocysts] - Isospora belli Live intercellular during the part of their life cycle - Toxoplasma gondii - They need one organism to complete their life cycle Phylum Microspora They are also classified under Phylum apicomplexa - Enterocytozon bineusi because of their apical complex - There are certain structures needed for attachment - Encephalitozoon spp. or penetration to host cells - Vittaforma cornea - Pleistophora spp. CLASSIFICATION OF PROTOZOAN PARASITES - Brachila vesicularum - Microsporidium spp. MALARIA from Italian word “mal’aria” which means “bad air” - “mal” meaning bad - “aria” meaning air - Malaria: bad air During 18th century in Italy, it is believeed to be caused of foul emanation from the marshy soil - Galing sa mabahong odor na nanggaling sa lupa Considered to be the most important parasitic disease affecting man (Belizario, 2015) Phylum Apicomplexa Vector: female Anopheles mosquito - Plasmodium spp. o Plasmodium falciparum – responsible for 1 ̊ [Primary vector]: Anopheles minimus var. flavirostris 90% of the malarial cases Others: Anopheles litoralis, Anopheles maculates, o Plasmodium vivax – responsible for 90% of Anopheles mangyamus the malarial cases Final Host: Female Anopheles mosquito o Plasmodium malariae Intermediate Host: Man/Humans o Plasmodium ovale Infective stages: sporozoites (man); gametocytes o Plasmodium knowlesi – 5th human malarial (mosquito) parasite; not usually common in human - Sexual stage: happens in the mosquitoes [usually in monkeys, but in the Philippines, o Infective stage: gametocytes there has been a reported case of this - Asexual stage: happens in humans parasite (last 2006)] o Infective stage: sporozoites 1|Page J.M.J.R.  Malaria has been identified by the World Health SOURCES OF EXPOSURE TO INFECTION Organization as one of the three major infectious Vector-borne (Arthropod borne) disease threats, along with Human Immunodeficiency Other modes of transmission: Virus/Acquired Immune Deficiency Syndrome and 1. Imported malaria Tuberculosis o From other countries endemic with malaria - Increasing cases of malaria especially during the and transfer the disease with other people rainy season 2. Transfusion malaria Malaria mostly affects young children and pregnant o During blood donations women 3. Mainline malaria - Especially in endemic areas [prone na makagat ng o Sharing of needles (drug users) lamok] 4. Congenital malaria PERIODICITY/FEBRILE CYCLE o Vertical transmission via placenta [mother to fetus] Malarial diseases are referred to their outstanding Vector Biology: Anopheles flavirostris clinical features – fever or febrile cycle Aquatic Habitat: slow flowing streams; shaded streams - Interval of acquisition of fever - Also the habitat for dengue mosquitoes - Water sources that are not moving or slow moving Adult biting: Night biting (indoor and outdoor) Adult resting: inside walls THE MOSQUITO CYCLE Plasmodium knowlesi – Quotidian malaria [24 hrs; every 24 hrs, nagkakaroon ng fever] Tertian – 48 hours Subtertian – 36-48 hours Quartan – 72 hours Falciparum, vivax, ovale – fever appears every second day or alternate days Malariae – every 3rd day ang labas ng fever Life cycle of malarial parasites typically involves 2 hosts: Malaria – associated with P. falciparum human (intermediate host) and mosquito (definitive host) 2|Page J.M.J.R.  Sexual phase happens on female anopheles mosquito - Dito nangyayari ‘yung formation ng sporozoites [sporogony phase] - Maturation and fertilization takes place inside the body of the mosquito [Sexual Cycle or Sexual Multiplication] When a female mosquito bites and sucks the blood of the human host, it will go to the stomach and the blood may contain the female and male gametocyte In the mosquito, the male and female gametocyte will undergo maturation - microgametes/microgametocytes: male; - macrogametes/macrogametocytes: female o fertilization will happen = formation of zygote o when they form a zygote, it will become elongated and active o once in an active form, it will form ookinetes will penetrate the stomach wall of the mosquito and develops into an oocysts o oocysts will continue to grow and develop and may form a slender or thread-like form Exflagellating male gametocytes: the nuclear material that will be called as sporozoite and cytoplasm of the male gametocytes divides to o the oocysts will be ruptured [releasing produce 8 microgametes with long, actively motile, sporozoite]; released throughout the body whip-like filaments. of the mosquito The female gametocyte does not divide but undergoes a o those sporozoites will undergo a cycle process of maturation to become the female gamete or [mapupunta sa salivary glands ng mosquito; macrogamete. It is fertilized by one of the kaya kapag nakakagat, mappenetrate sa host or human] microgametes to produce the zygote. - there are sporozoites that will go to the salivary Ookinete: the zygote, which is initially a motionless, glands of mosquito, but there are also sporozoites round body, gradually elongates becomes a vermicular that will go to the liver of human [will be the cause motile (traveling vermicule) form with an apical of asexual multiplication or the pre-erythrocytic or complex anteriorly. exoerythrocytic cycle] Oocyst: rounded into a sphere with an elastic o salivary glands: cycle is called sporogonium membrane within which numerous sporozoites are o liver: cycle is called pre-erythrocytic or formed. exoerythrocytic Sporozoites: when the oocysts ruptures, the sporozoites - the sexual phase or the sporogony cycle or enter into the hemocele or body cavity, from where mosquito cycle does not only depend on the specie some find their way to the mosquito’s salivary glands. of plasmodium, but also to the mosquito host The mosquito is now infective and when it feeds on o may mga specie na mas mabilis ang humans, the sporozoites are injected into skin multiplication inside the mosquito capillaries to initiate human infection. [depending on the temperature of the environment] 3|Page J.M.J.R.  o example: Plasmodium vivax has the fastest o Important stage because in this stage sexual stage [8 days]; Plasmodium malariae parasites can invade the erythrocytes has 35 days of sexual stage In the erythrocytic cycle, the merozoites will invade the Red Blood Cells, but some of them like Plasmodium vivax and ovale will reinvade the liver cells - Once bumalik sila sa liver cells, there will be a dormant stage [sleeping stage or called as hipnozoites] - These parasites that invade the red blood cells in the bloodstream, they will undergo erythrocytic cycle that will last up to 44-72 hours. - For each infected red cell, the product will be 4-36 new parasites At the end of the schizogony cycle, the infected red cells will rupture, liberating all merozoites to infect new red cells - Ruptured red blood cells will liberate products of metabolism of parasites - Not all red blood cells will undergo metabolism [hemozoin: pigment of hemoglobin] - During the rupture of red blood cell, doon nangyayari ang fever or lagnat - From liver -> rupture liver cells -> infect red blood cells PRE-ERYTHROCYTIC (TISSUE) STAGE OR EXOERYTHROCYTIC STAGE [SCHIZOGONY OR ASEXUAL CYCLE] The hepatocyte is distended by the enlarging schizont Asexual multiplication is called as Schizogony stage or and the liver cell nucleus is pushed to the periphery Schizogony cycle These normally rupture in 6-15 days and release This happens in the liver thousands of merozoites into the blood stream - The sporozoites enter or infect the liver cells = Hypnozoites (hypnos: sleep): resting forms in schizonts [term used to call sporozoites that has Plasmodium vivax and Plasmodium ovale entered the liver] - The rupture of infected liver cells will release the merozoites into the circulation o Enter and infect the red blood cell [erythrocytic cycle] - Schizogony stage: malarial parasites multiplies by dividing or splitting the process designated to shizogoniae = to form schizonts o Occurs in two locations: liver Plasmodium falciparum and Plasmodium malariae – has [exoerythrocytic cycle] and in the red blood no sleeping stage; completely undergo the three cycles cell [erythrocytic cycle] in all of the 4 species, asexual multiplication takes place in the liver cells, but in the case of Plasmodium vivax 4|Page J.M.J.R.  and Plasmodium ovale, they will undergo dormant or The appearance of malaria pigments varies in different sleeping stage species as follows: - sporozoites will enter sleeping or dormant stage = - P vivax: numerous fine golden-brown dust-like hypnozoites particle - P. falciparum: few 1–3 solid blocks of black pigment ERYTHROCYTIC STAGE - P. malariae: numerous coarse dark brown particles The merozoites released by pre-erythrocytic schizonts - P ovale: numerous blackish brown particles. invade the red blood cell: Amoeboid form or late trophozoite form: as the ring - The receptor for merozoites is glycophorin, which is form develops, it enlarges in size becoming irregular in a major glycoprotein on the red cells. shape and shows amoeboid motility. - Merozoites are pear-shaped bodies, about 1.5 μm When the amoeboid form reaches a certain stage of in length, possessing an apical complex (rhoptery). development, its nucleus starts dividing by mitosis They attach to the erythrocytes by their apex. followed by a division of cytoplasm to become mature - Ring forms or young trophozoites: the merozoite schizonts or meronts. loses its internal organelles and appears as a The merozoites invade fresh erythrocytes within which rounded body having a vacuole in the center with they go through the same process of development. the cytoplasm pushed to the periphery and the The rupture of the mature schizont releases large nucleus at one pole. quantities of pyrogens. - Malaria pigment or haemozoin pigment: parasite This is responsible for the febrile paroxysms feeds on the hemoglobin of the erythrocyte but it characterizing malaria. does not metabolize hemoglobin completely and therefore, leaves behind a hematin-globin pigment as residue. P. vivax: signet ring appearance with schuffner’s dots [fine red granules] P. malariae: elongated band or stab, stretching to the entirety of red blood cells [the dots are called as Plasmodium vivax – described as the delicate ring Ziemann’s stippling] - Called as “vivax” because it means in latin is P. falciparum: compact with cytoplasmic vacuolation; vigorous [malilikot] almost ring-shaped, but with dark red or wedge-shaped Plasmodium malariae – compact ring dots [Maurer’s dots] Plasmodium falciparum – very delicate ring P. ovale: malarial’s stipplings are called Jame’s dots Plasmodium ovale – dense ring Accole forms: crescentic masses (moon-shaped; peripheral part of the red blood cells) - P. falciparum has accole forms 5|Page J.M.J.R.  Male gametocytes: blunted edges Female gametocytes: pointed edges P. malariae: flower-like appearance ; daisy-head - Average merozoites: 8 GAMETOGONY Development of gametocytes generally takes place within the internal organs and only the mature forms COMPONENTS OF THE MALARIA LIFE CYCLE appear in circulation. The mature gametocytes are round in shape, except in P. falciparum, in which they are crescent-shaped or sausage-shaped. In all species, the female gametocyte is larger (macrogametocyte) than the male gametocyte (microgametocyte). The gametocytes do not cause any clinical illness in the host, but are essential for transmission of the infection. A gametocyte concentration of 12 or more per cumm of blood in the human host is necessary for mosquitoes to become infected. 6|Page J.M.J.R.  INTERVALS MALIGNANT TERTIAN MALARIA The most serious and fatal type of malaria is malignant tertian malaria caused by P. falciparum. PERNICIOUS MALARIA Pernicious malaria has been applied to a complex of life-threatening complications that sometimes supervene in acute falciparum malaria. CEREBRAL MALARIA Incubation period: time between the sporozoite Cerebral Malaria: is the most common cause of death injection and appearance of clinical signs and symptoms in malignant malaria, capillary plugging of cerebral - Depends on the parasite strain, immune status of microvasculature, which results in anoxia, ischemia, human, and depending on the sporozoite entered and hemorrhage in brain. BLACKWATER FEVER CLINICAL FEATURE Blackwater fever: malarial hemoglobinuria, is sometimes seen in falciparum malaria. Clinical BENIGN MALARIA manifestation include bilious vomiting and The typical picture of malaria consists of periodic bouts prostration, with passage of dark red or blackish of fever with rigor, followed by anemia and urine (black water). splenomegaly. Severe headache, nausea, and vomiting There is a massive intravascular hemolysis caused by are common. anti-erythrocyte antibodies, leading to massive absorption of hemoglobin by the renal tubules CLASSICAL MALARIA PAROXYSMS (hemoglobinuric nephrosis) 1. COLD STAGE ALGID MALARIA - Starts with the sudden coldness and Algid Malaria: peripheral circulatory failure, rapid apprehension thready pulse with low blood pressure, and cold - mild shivering turns to teeth chattering and clammy skin. There may be severe abdominal pain, shaking of the whole body vomiting, diarrhea, and profound shock. - may last for 15 to 60 minutes SEPTICEMIC MALARIA 2. HOT STAGE/ FLUSH PHASE : BEST STAGE TO COLLECT Septicemic malaria: high continuous fever with BLOOD SAMPLE dissemination of the parasite to various organs, - high temperature (40-41 C ̊ ) [best time to collect leading to multiorgan failure. Death occurs in 80% of blood sample], headache, palpitations, epigastric the cases. discomfort, thirst, nausea and vomiting MEROZOITE-INDUCED MALARIA - patient is confused and delirious Injection of merozoites can lead to direct infection of - may last for 2 to 6 hours red cells and erythrocytic schizogony with clinical 3. SWEATING STAGE (DEFERVESCENCE OR illness. Such merozoite-induced malaria may occur in DIAPHORESIS) transfusion malaria, congenital malaria, renal - Defervescence: disappearance or lowering of transplantation and mainline malaria. fever TROPICAL SPLENOMEGALY SYNDROME - Diaphoresis: excessive sweating due to fever Also known as hyper-reactive malarial splenomegaly - profuse sweating, temperature lowers and (HMS) is a chronic benign condition seen in some symptoms diminishes adults in endemic areas, mainly tropical Africa, New - may last for 2 to 4 hours Guinea, and and Vietnam. Abnormal immunological response to malaria causing splenomegaly, high titers of circulating anti-malaria antibodies and absence of malaria parasites in peripheral blood smears, hypergammaglobulinemia 7|Page J.M.J.R.  (IgM), cryoglobulinemia reduced C3, and presence of rheumatoid factor without arthritis. Recrudescence: new malarial attacks that appear after a period of latency usually within 8 weeks after the primary attack and resulting from persistence of the erythrocytic cycle of the parasites. Relapse: common to P. vivax and P. ovale infections, as result from the reactivation of hypnozoite forms of the parasite in the liver. PATHOLOGICAL PROCESS OF THE RBC 1. Poikilocytosis and Anisocytosis 2. Altered RBC membrane transport 3. RBC stiffness and cytoplasmic viscosity IMMUNITY DUFFY NEGATIVE RBCs MORPHOLOGY It has been found that persons, who lack the Duffy blood group (Fya and Fyb alleles) antigen, are refractory to infection by P. vivax. These genetically determined blood group antigen appears to be the specific receptor for P. vivax. NATURE OF HEMOGLOBIN Hemoglobin E provides natural protection against P. vivax. P. falciparum does not multiply properly in sickled red cells containing HbS. Sickle cell anemia trait is very common in Africa, where falciparum malaria is hyperendemic and offers a survival advantage. HbF present in neonates protects them against all Plasmodium species. - If there’s a problem in the hemoglobin of red blood cells, it can’t be targeted by the malarial parasites 8|Page J.M.J.R.  G6PD DEFICIENCY Innate immunity to malaria has also been related to G6PD deficiency found in Mediterranean coast, TREATMENT Africa, Middle East, and India. PROTECTIVE - The red blood cells here are bite cells; resistant to Chemoprophylaxis: Objective is to prevent infections Plasmodium falciparum in non-immune person visiting endemic areas HLA-B53 (Mefloquine and Doxycycline) HLA-B53 is associated with protection from malaria. CURATIVE There is some evidence that severe malnutrition and Therapeutic: Objective is to eradicate the erythocytic iron deficiency may confer some protection against cycle and clinical cure. malaria. Radical cure: Objective is to eradicate the exoerythrocytic cycle in liver to prevent relapse. - Artemether-Lumefantrine (Coartem TM) – first DIAGNOSIS line drug for confirmed P. falciparum cases. Not MICROSCOPY (GOLD STANDARD) recommended in pregnancy, lactation and “THICK AND THIN BLOOD SMEAR” infants. stained with Giemsa or Wright’s stain - Quinine (plus Tetracycline or Doxycycline) – perform multiple sets of blood films (blood collected second line drug for confirmed P. falciparum every 6 to 12 hours for up to 48 hours) cases which AL fail or not available. MANNER OF REPORTING - Quinine IV drip – drug of choice for complicated A. QUALITATIVE or severe P. falciparum malaria. PREVENTIVE Gametocidal: Objective is to destroy gametocytes to prevent mosquito transmission and thereby reducing human reservoir. - In addition to AL and Q+T,D, Primaquine is given B. QUANTITATIVE on the 4th day as single dose to prevent transmission QUANTITATIVE BUFFY COAT (QBC) PREVENTION uses a special capillary tube with acridine orange (+) bright green and yellow under fluorescent 1. Use of mosquito repellant microscope 2. Use of insecticide treated nets (ITN) RAPID DIAGNOSTIC TEST (RDT) 3. Take prophylactic medication detects Plasmodium-specific antigens in finger prick 4. Wearing of light-colored clothing which cover most of sample the body A. Histidine-rich protein II (HRP II) – water soluble CONTROL CHON produced by trophozoites and young gametocytes (e.g., Paracheck Pf test, ParaHIT f 1. Environmental cleanliness test) - (stream cleaning to speed up water flow and B. Plasmodium LDH – produced by both sexual and exposing to sunlight) asexual stages and can distinguish between P. 2. Indoor residual sprayin falciparum and non-P. falciparum (DiaMed 3. Zooprophylaxis – use of carabao to deviate mosquitoes OptiMAL IT) 4. Use of biologic control methods SEROLOGIC TESTS a. Bacillus thuringiensis – larvicidal IHA, IFAT, ELISA b. Larviparous fishes (e.g., Oreochromis niloticus) MOLECULAR METHODS Through PCR (low cases and mixed infection) 9|Page J.M.J.R.  Plasmodium knowlesi A primate malarial parasite common in South East Asia Causes malaria in long tailed macaques (Macaca fascicularis) May also infect humans The appearance of P. knowlesi is similar to that of P. malariae. 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) Babesia spp. (Babesia microti, Babesia divergens and Babesia bovis) First described to cause “Texas cattle fever or red water fever” Blood parasites that cause malaria-like infections “Babesiosis” – pathology due to Babesia spp. Life cycle of Babesia spp. undergo three stages: Parasites divide through binary fission or budding 1. Merogony in the red blood cells of tick vectors Cycle in the tick is still uncertain 2. Stage in the gut and epithelium Vector: Ticks (Ixodes scapularis) 3. Sporogony in humans c. Hard ticks Babesia infected tick once nakakagat, need magkroon d. Scapularis – capable of carrying Borrelia burgdorferi ng contact for 12 hours para magkaroon ng effective → CA of Lyme disease transmission Definitive Host: Ixodid ticks - That cycle will infect the red blood cells producing Intermediate Host: Man or other mammals merozoites and trophozoites, producing continuous Infective form: Sporozoites cycle, but the diagnostic characteristic is the Mode of Transmission: bite of the nymphal stage of maltese cross or tetrads formation Ixodid ticks - In humans, merozoites, from infected cells -> Other modes of transmission: infecting red blood cell e. Blood transfusion In mouse, merozoites will form gametes. Once gametes f. Organ transplantation are ingested by another tick, they will travel through the g. Transplacental route gut of the tick for fertilization to form zygote and Diagnostic stage: “Maltese cross” – arrangement of the transform intro ookinete to infect another host merozoites and ring-form trophozoite Sporogony happens resulting to numerous release of sporozoite. Once sporozoite is released, it will be transmitted to another host 10 | P a g e J.M.J.R.  PATHOLOGY Associated with excessive pro-inflammatory cytokines such as the tumor necrosis factor (TNF) Most cases are subclinical and may occur as self- limiting Headache, high-grade fever, chills, vomiting, myalgia, DIC, hypotension, respiratory distress and renal insufficiency. DIAGNOSIS 1. Microscopy of the Giemsa-stained peripheral blood smear A. Merozoites in Maltese cross arrangement B. Ring form → most frequent intraerthrocytic form found 2. PCR (gold standard) 3. Immunofluorescent assays (IFA) 4. Immunochromatographic test (ICT) 5. Hamster Intraperitoneal Inoculation TREATMENT Clindamycin – Drug of choice Drug combination: Clindamycin and Quinine or Azithromycin and Atovaquone Chloroquine – former drug of choice (it only improve the symptoms but not the degree of the parasitemia) In the Philippines: human babesiosis is not yet reported however, it could be present in dogs (Babesia canis). PREVENTION AND CONTROL avoidance of places where ticks are usually found wearing of light-colored pants tucked into one’s socks tick check (especially for children) rodent population should be controlled 11 | P a g e J.M.J.R.  PARA311: CLINICAL PARASITOLOGY TOPIC: COCCIDIAN PARASITES 1ST SEMESTER | S.Y 2024-2025 LECTURER: Prof. Rose Dyane Hizola, RMT, MPH TOPIC Immature oocyst seen in the feces of patients contain SUBTOPIC two sporoblasts. SUB SUBTOPIC The oocysts mature outside the body. On maturation, the sporoblast convert into sporocysts. Each sporocyst contain 4 crescent shaped sporozoites COCCIDIAN PARASITES Infective stage: Sporulated oocyst containing 8 sporozoites is of the parasite Unicellular protozoans that is under class Sporozoa Mode of transmission: ingestion of food and water (Phylum Apicomplexa) contaminated with sporulated oocysts or mature cyst - Group of microscopic, spore-forming, unicellular, obligate intercellular protozoans Intercellular protozoans; some of their life cycle, they live inside the cells They are intestinal coccidians In class Sporozoa, the life cycle is characterized by an alternations of generation: 1. Sexual: Sporogony 2. Asexual: Schizogony Cystoisospora belli Immature cysts: contains two sporoblasts Cryptosporidium hominis When these sporoblasts develop, these will become Cyclospora cayetanensis sporocysts Toxoplasma gondii Inside the sporocyst, it will have 4 crescent shaped Sarcocystis hominis and Sarcocystis suihominis sporozoites [4-curved sausage-like known as The alternating sexual phase are characterized by three sporozoites – mature stage] (3) sequential stages: 1. Sporogony – sexual cycle that produces the oocysts 2. Schizogony or merogony – asexual phase that produce that merozoites the merons 3. Gametogony – results of the development of male and female gametocytes [Plasmodium spp. gametocytes] Cystoisospora belli formerly known as Isospora belli – parasites of the epithelium cells of the intestines MORPHOLOGY Oocysts of Cystoisospora belli are elongated ovoid and measure 24 um x 15 um. Immature oocysts are released from the intestinal walls Each oocysts is surrounded by a thin, smooth, 2- in the form of feces layered cyst wall 1|Page J.M.J.R.  - That stool will mature into oocysts that have TREATMENT sporozoites Asymptomatic: bland diet and bed rest [water - Maturation from immature oocysts to mature therapy for hydration and bland diet (meaning soft, oocysts will take about 4-5 days not spicy, and not rich in fiber foods)] Mature oocysts that have sporozoites will be ingest by Symptomatic: Trimethoprim-sulfamethoxazole [3 the human host weeks ‘tog binibigay for positive cases] - Ex. Contaminated water or food have contaminated PREVENTION AND CONTROL oocysts and ingested, it will enter the body of the Good sanitary practices host [excystation in the small intestine] Thorough washing and cooking of food Provision for safe drinking water Inside the body, in the small intestine, the sporozoites will undergo another asexual cycle to form merozoites - Merozoites will invade new epithelial cells to Cryptosporidium hominis continue the asexual multiplication - Some merozoites will undergo gametogony Cryptosporidium hominis are minute coccidian parasites [fertilization] [small parasites; they are know to infect the humans - Then, new oocysts will be formed and some of the mammals] - That oocysts when released from the body, could Oocysts of the C. hominis is the infective stage ingest another susceptible host The oocyst is spherical or oval and measures about 5 μm in diameter. PATHOLOGY Oocysts does not stain with iodine and is acid fast. Infection is usually asymptomatic Thin-walled oocysts are responsible for autoinfection. Symptomatic: diarrhea, fever, malaise, abdominal Both thin walled and thick-walled oocyst contain 4 pain and flatulence crescent-shaped sporozoites. Disease is common to children and male homosexuals with AIDS In AIDS patients, reports on dissemination of parasite to other organs are present. - They are affected with this parasites because there are reported cases that this parasite travel to different organs besides the small intestines DIAGNOSIS Direct microscopy For the diagnosis, direct microscopy or microscopic examination using iodine [makikita ang oocysts]; difficult to examine kasi transparent sila Concentration technique (FECT, ZnSO4 and sugar floatation) - We can do the concentration technique; the zinc sulfate method, sugar floatation [most sensitive and most accurate method for detecting isospora belli], and the formalin ether concentration technique Staining techniques (Iodine, Kinyoun, Auramine- Rhodamine) Enterotest and duodenal aspirate Molecular testing or PCR 2|Page J.M.J.R.  MORPHOLOGY One person to another: infected food handlers Infective Stage: oocyts Nosocomial infection DIAGNOSIS Sheather’s sugar floatation, Zinc sulfate floatation technique and Formalin ether/ethyl acetate concentration technique Kinyoun’s modified acid-fast stain (oocyst appear as red-pink doughnut-shaped circular organisms): cheapest and simplest method of diagnosis IFA [Indirect Fluorescent Assay] DNA probe TREATMENT No acceptable treatment yet Supportive therapy with fluid, electrolytes, and nutrient replacement. Nitazoxanide is said to be effective in preliminary studies Bovine colostrum, paromomycin and clarithromycin: treatment of severe diarrhea PREVENTION AND CONTROL Chlorination is not effective Use of multiple disinfectant and combined water treatment Proper disposal of human and animal excreta When ingested, the sporozoites attach to the surface of epithelial cells of the gastrointestinal tract Cyclospora cayetanensis Develop into small trophozoites These trophozoite will divide through schizogony to The oocyst is a non-refractile sphere, measuring 8– produce merozoites 10μm in diameter. It contains 2 sporocysts. Eventually, merozoites will develop into gametocytes Each sporocyst contains 2 sporozoites. Hence, each [zygote] sporulated oocyst contains 4 sporozoites Almost the same as cryptosporidium; known for watery Zygote will produce oocysts [result of the zygotes] diarrhea Thin-walled oocysts will infect intestinal cells and the thick-walled oocysts will pass through the feces MORPHOLOGY Infective Stage: oocyts PATHOLOGY Disease is usually self-limiting Immunocompetent: self-limiting diarrhea within 2-3 MOT: ingestion weeks Immunocompromised: severe diarrhea, bile duct and gallbladder maybe heavily infected, blunted intestinal villi, varying degrees of malabsorption and excessive fluid loss AIDS patient: severe form of diarrhea, progressively worse and life-threatening SOURCES OF INFECTION Faulty water purification system Swimming in contaminated recreation water 3|Page J.M.J.R.  - Lasts up to 3 weeks; no deaths associated with this parasite - Self-limiting; may last up to several weeks - Associated with AIDS patients DIAGNOSIS DFS Concentration techniques Kinyoun stain Fluorescent microscopy Safraning staining PCR TREATMENT No treatment needed If pharmacologic treatment is warranted, cotrimoxazole is given. If diarrheal symptoms are prominent, either metronidazole or iodoquinol can be used. PREVENTION AND CONTROL Good sanitary practices Access to safe and clean drinking water Proper food preparation Toxoplasma gondii MORPHOLOGY Infective Stage: trophozoite (tachyzoite), tissue cyst (bradyzoite) and the oocyst - Infect different vertebra or vertebrae host - Occurs in domestic cats [feline family] Definitive host: Cats (complete life cycle occurs in cats) - Support shizogony and gametogony A. Unsporulated oocyst – cannot differentiate the Clinical manifestation is apparent if immune system is cytoplasm; 2 immature sporocysts suppressed. B. Oocysts that mechanically ruptured C. Free or released sporocysts; 2-phase sporozoites D. Oocysts Under the UV light, it will appear bluish green or bluish circle – important characteristic or criteria for identifying Cyclospora cayetanensis [autofluorescent criteria] PATHOLOGY Chronic and intermittent watery diarrhea occurs in early infection and may alternate with constipation. Fatigue, anorexia, weight loss, nausea, abdominal pain, flatulence, bloating and dyspnea may develop. Infections are usually self-limiting. No death is associated. 4|Page J.M.J.R.  - The bradyzoite are release in the small intestine and will undergo multiple asexual multiplication leading to formation of merozoite. - Some of the merozoites they enter in intestinal tissues resulting to formation of tissue cyst and other merozoites transform in male and female gametocytes and formation of macrogametes and microgametes begin. - After the fertilization of gametocytes, it will result to mature oocyst containing sporozoite that is infective to human. Exoenteric Cycle occurs in the humans - Only the tissue cyst and tachyzoite are exhibited by intermediate host including the humans. The sporozoite from the oocyst and the bradyzoite from tissue cyst enter intestinal mucosa and multiply asexually and the tachyzoite are form. The tachyzoite are spread to distant extra-intestinal organ like brain, eyes, and other nature organ. Here, producing two (2) stages, tachyzoite and bradyzoite. PATHOLOGY Toxoplasmosis commonly asymptomatic, if immune system is good. Active progression of infection is more likely in immunocompromised individuals. is the most common manifestation. CONGENITAL TOXOPLASMOSIS Results when T. gondii is transmitted transplacentally from mother to fetus. Most infected newborns are asymptomatic at birth and may remain so throughout. Some develop clinical manifestations of toxoplasmosis weeks, months, and even years after birth. Enteric Cycle: occurs in the definitive host which are Manifestations: chorioretinitis, cerebral calcifications, cats convulsions, strabismus, deafness, blindness, mental - Both sexual reproduction (gametogony) or asexual retardation, microcephaly, and hydrocephalus. reproduction (schizogony) occur in the mucosal ACQUIRED TOXOPLASMOSIS epithelial of the small intestine of the cats. Infection acquired postnatally is mostly - The life cycle is complete, there is sexual and asymptomatic. asexual reproduction. he most common manifestation of acute acquired - The cat will acquired the infection if they have toxoplasmosis is lymphadenopathy; the cervical eaten rats that infected with tissue cyst or directly lymph nodes being most frequently affected. digested the oocyst. 5|Page J.M.J.R.  IMAGING Magnetic resonance imaging (MRI) and computed tomography (CT) scan are used to diagnose toxoplasmosis with central nervous system involvement. Ultrasonography (USG) of the fetus in utero at 20–24 OCULAR TOXOPLASMOSIS weeks of pregnancy is useful for diagnosis of It may present as uveitis, choroiditis, or chorioretinitis congenital toxoplasmosis. TOXOPLASMOSIS IN IMMUNOCOMPROMISED PATIENTS Most serious and often fatal in immunocompromised TREATMENT patients, particularly in AIDS, whether it may be due to reactivation of latent infection or new acquisition Congenital toxoplasmosis: pyrimethamine and of infections. sulfadiazine Ocular toxoplasmosis: pyrimethamine plus either sulfadiazine or clindamycin. DIAGNOSIS Immunocompromised patients: Trimethoprim MICROSCOPY sulfamethoxazole is the drug of choice, dapsone- Tachyzoites and tissue cysts can be detected in pyrimethamine is the recommended alternative drug of various specimens like blood, sputum, bone marrow choice aspirate, cerebrospinal fluid (CSF), amniotic fluid, and biopsy material from lymph node, spleen, and brain. PREVENTION AND CONTROL Smear made from above specimens is stained by Good sanitation and hygiene Giemsa, PAS, or Gomori methenamine silver (GMS) stain. Tachyzoites appear as crescent shaped Proper food preparation structures with blue cytoplasm and dark nucleus Pregnant women should avoid contact with cats ANTIBODY DETECTION Acute infection with T. gondii can be made by detection of the simultaneous presence of IgM and Sarcocystis hominis and Sarcocystis suihominis IgG antibodies. Tests for detecting IgG antibody include: Enzyme Sarcocystis species produce cyst in the muscle of the linked immunosorbent assay (ELISA), Indirect intermediate hosts. These cysts, called Sarcocysts, fluorescent antibody test (IFAT), Latex agglutination contain numerous bradyzoites test and Sabin Feldman dye test ANTIGEN DETECTION Detection of antigen by ELISA indicates recent Toxoplasma infection. Useful in AIDS and other immunocompromised patients. Detection in amniotic fluid is helpful to diagnose congenital toxoplasmosis SKIN TEST OF FRENKEL Diluted toxoplasmin is injected intradermally and delayed positive reaction appears after 48 hours. This test is not very reliable for diagnosis of toxoplasma. MOLECULAR METHODS DNA hybridization techniques and polymerase chain reaction (PCR) are increasingly used to detect Toxoplasma from different tissues and body fluids 6|Page J.M.J.R.  DIAGNOSIS Fecal floatation methods: sporocysts will be seen Demonstration of sarcocysts in the skeletal muscle and cardiac muscle by biopsy or during autopsy. Western blot Serologic tests (IFA, ELISA) PCR TREATMENT No specific treatment is available for sarcocystosis. Corticosteroids were found to be useful in muscular inflammation Trimethoprim-sulfamethoxazole is seen as potentially effective in treating intestinal infections PREVENTION AND CONTROL Uncooked animal carcass should not be fed to other animals Avoiding eating raw or undercooked beef or pork Thoroughly cooking and freezing meat to kill bradyzoites When the Sarcocystis eaten by definitive host, the merozoite are release in intestine where they develop male and female gametocyte. After the fertilization, the zygote develops an oocyst containing 2 sporocyst, each having 4 sporozoites insides. These oocysts are shed in the feces and are ingested by the intermediate host. This are already mature oocyst; they readily infect the susceptible host. Once it gets by intermediate host such as cows and pigs, the sporocyst will rapture, releasing the sporozoite and enter to endothelial cells of blood vessels and under schizogony. Schizont rapture releasing the merozoite and merozoite under muscle cells and develop cyst with bradyzoite. Infective and Diagnosis stage: Cyst with bradyzoite ingested in under cook meat or the Sporocyst and Thin- walled oocyst that are pass in the feces PATHOLOGY Sarcosporidiosis and sarcocystosis Gastroenteritis, diarrhea, myalgia, weakness, fever For intermediate host, brain, muscle and kidney tissues maybe damaged. May cause abortion to cows 7|Page J.M.J.R.  PARA311: CLINICAL PARASITOLOGY TOPIC: INTRODUCTION TO NEMATODES AND FILARIAL WORMS 1ST SEMESTER | S.Y 2024-2025 LECTURER: Prof. Rose Dyane Hizola, RMT, MPH TOPIC Male is generally smaller than female and its posterior SUBTOPIC end is curved or coiled ventrally SUB SUBTOPIC Female nematodes may be oviparous (producing eggs), viviparous (producing larvae) or ovoviviparous (lay eggs containing larvae which immediately hatch out) NEMATODES Nematodes subphylum filarial worms Said to be the most worm-like out of all the helminths Resemble the common earthworms in appearance – considered to be the prototype of the worms There are estimated 500,000 species of nematodes. They are considered as parasites, causing not only to humans, but also to animals GENERAL CHARACTERISTICS The name, “Nematode” – from “Nema”, meaning “threadlike” Shape: elongated, cylindrical or filariform in shape, unsegmented worms with tapering ends: LIFE CYCLE Sensory organs (with exception): Consists typically of 4 larval stages and the adult form - Amphids (anterior) - 2 larva; 2 adults o Looks like a cuticular depression present in - The eggs vary in size and shape and the larva the mouth/lips surrounding the mouth in undergo 4 stages the nematodes and they serve as o Have several molting processes happening chemoreceptors [responsible for their until they reach the third larval stage modulation of their chemorepulsion [filariform: infective form of the parasite] behavior: movement away from a The cuticle is shed while passing from one stage to the substance] other. - Phasmids (posterior) Man is the optimum host for all the nematodes. Locomotion: move by contraction of the longitudinal They pass their life cycle in one host, except for the muscles Filarial worms and Dracunculus medinensis where two Body wall: covered with a tough outer cuticle (smooth, hosts are required. striated, bossed, or spiny), middle layer is hypodermis Nematodes localize in the intestinal tract and their and the inner layer is the somatic muscular layer eggs/ova pass out with the feces of the host. - The cuticles of the body wall of a nematode is a Nematodes have different sexes. They are equipped tough protective covering made up of chitin. with reproductive system and a digestive system Sexes: Diecious - Diecious: the sexes are separate (there is a female and male parasite) 1|Page J.M.J.R.  LARGE INTESTINE - Trichuris trichiura - Enterobius vermicularis SOMATIC HUMAN NEMATODE LYMPHATICS - Wuchereria bancrofti - Brugia malayi - Brugia timori SKIN OR SUBCUTANEOUS TISSUE - Loa loa - Onchocerca volvulus - Dracunculus medinensis CLASSIFICATION OF NEMATODES MESENTERY - Mansonella ozzardi PRESENCE OR ABSENCE OF CHEMORECEPTORS - Mansonella perstans Phasmid nematode – with caudal chemoreceptors CONJUCTIVA - These are parasites with caudal chemoreceptors - Loa loa o Caudal chemoreceptors are important in modulation of their chemorepulsion behavior [chemorepulsion behavior: direction or movement away of certain FILARIAL WORMS substances] GENERAL CHARACTERISTICS Aphasmid nematode – without caudal chemoreceptors Filarial worms came from the Latin word “filum” INFECTIVE STAGES AND MODES OF TRANSMISSION meaning thread. Ingestion of embryonated eggs – Ascaris, Trichuris, Slender thread-like worms Enterobius Mode of transmission: by the bite of blood-sucking Ingestion of infective larva – Capillaria, Trichinella, insects or mosquito Angiostrongylus Female worms are viviparous and give birth to larvae Ingestion of encysted larvae in muscle – Trichinella known as microfilariae Skin penetration of L3 (filariform larvae) – Hookworms - Found in the capillaries or blood vessels in the lungs and Strongyloides when they are not present in the peripheral blood Vector-borne – Wuchereria and Brugia Characterized according to their Periodicity: time of Autoinfection – Strongyloides and Enterobius appearance of microfilaria in the blood that can be Transmission through inhalation – Enterobius and detected or visualized under the peripheral blood Ascaris smear - Nocturnal periodicity: when the largest number of HABITAT microfilariae occur in blood at night INTESTINAL HUMAN NEMATODE o Wuchereria bancrofti SMALL INTESTINE - Diurnal periodicity: when the largest number of - Ascaris lumbricoides microfilariae occur in blood during day - Ancylostoma duodenale o Loa loa - Necator americanus - Nonperiodic: when the microfilariae circulate at - Strongyloides stercoralis constant levels during the day and night - Trichinella spiralis o Onchocerca volvulus - Capillaria philippinensis - Subperiodic or nocturnally subperiodic: when the microfilariae can be detected in the blood 2|Page J.M.J.R.  throughout the day but are detected in higher MOT: Skin penetration through a vector numbers during the late afternoon or at night. - Ex. Mosquito bite o Brugia malayi Habitat: Lymphatic vessels (lymph nodes) Vector: - Aedes spp., Culex spp. and Anopheles spp. (W. bancrofti) - Mansonia spp. eg. M. bonnae and M. uniformis (B. malayi) Infective stages: - L3 larva or filariform larva (infective stage to man) - Microfilariae (infective stage to the mosquito) Diagnostic stage: Microfilariae (isolated in the blood) - Microfilariae migrates from the parent worm Covering: through the walls of the lymphatics papunta sa mga - Sheathed – covering or protection of parasite blood vessles near the lymph tissues. [envelope] Definitive host: Man - Unsheathed – no covering PARAMETER Wuchereria bancrofti Brugia malayi UNSHEATHED SHEATHED MICROFILARIA Common Bancroft’s filarial Malayan MICROFILARIA Name worm filarial worm Wuchereria bancrofti Onchocerca volvulus Culex spp. Brugia malayi Mansonella perstans Mansonia Vector Anopheles spp. Loa loa Mansonella ozzardi spp. Aedes spp. Habitat: Area Upper Lowe lymphatics LYMPHATIC SUBCUTANEOUS SEROUS CAVITY affected lymphatics FILARIASIS FILARIASIS FILARIASIS Nocturnal Wuchereria Loa loa [increase number Mansonella Periodicity of microfilariae in Subperiodic bancrofti Onchocerca perstans the blood at Brugia volvulus Mansonella night time] malayi Mansonella ozzardi Brugia timori streptocerca BANCROFTIAN FILARIASIS LYMPHATIC FILARIAL PARASITES Vector Biology : Wurchereria bancrofti & Brugia malayi - Anopheles flavirostris [Anopheles minimus var flavirostris – principal vector of malaria in the According to Dr. Belizario, lymphatic filariasis is one of Philippines] the most debilitating disease in many tropical countries o Also the vector of W. bancrofti - 2nd leading cause of permanent and long term o Usually found in Sulu and Palawan disability - Aedes poecillus - 2nd to psychiatric illnesses o Breeds in the water that accumulates in the - Not only affecting physical characteristics of the abaca and banana plant patient, but also their mental health Aquatic habitat: Axils of abaca and banana plant Filariasis – Parasitic infection caused by microscopic Adult biting: Day and night biting, indoor and outdoor threadlike worms acquired through a mosquito bite Adult resting: Base of abaca plants (cool, shady area) (vector borne) Has its social and economic impact 3|Page J.M.J.R.  LIFE CYCLE OF Wuchereria bancrofti LIFE CYCLE OF Brugia malayi Similar to W. bancrofti, they only differ in their Upon taking the blood from the infected person, the intermediate host and vector. mosquito can or may ingest the microfilariae [L3 larva: - Intermediate host: vecotrs of the mansonia and infective stage] aedes Microfilariae will be ingested by the mosquito and enters the stomach walls and thoracic cavity of the insect where they will grow and molt PATHOLOGY - Molting: from larvae 1 to larvae 3 [L1-L3] where they became the infective larva CLASSIC FILARIASIS The infective larva will migrate to the head of the insect Due to blockage of lymph vessels and lymph nodes by or on the sucking mouth of the insect the adult worms. The next time that the will eat or suck blood from a The blockage could be due to mechanical factors or human, they will puncture the skin and introduce the allergic inflammatory reaction to worm antigens and microfilariae to the new host [human] secretions. The infective larvae will have access to the lymphatic Why is the lymph nodes are involved or target of system of the individual and enters the lymph nodes filariasis? where they will mature - Because the lymph fluid is less aggressive than - If male and female are present in one area, they will blood. There are no platelets, complement mate to produce offspring or create new (incomplete coagulation system), granulocytes, and microfilariae [creation of new worms because of the the flow is much less violent and mas favorable sa mating of male and female worms] mga parasites compared sa blood Definitive host: human/man Intermediate host: vectors or female mosquitoes INFILTRATION: lymph nodes and vessels are infiltrated Infective and DIagnostic Stage: L3 larvae or with macrophages, eosinophils, lymphocytes, and plasma microfilariae cells LYMPH STASIS AND DILATION OF LYMPH VESSELS: vessel MOT: mosquito bites walls get thickened, and the lumen narrowed or occluded Target sites: lymphatic tissues or system GRANULOMA FORMATION: with subsequent scarring The mosquitoes here are not just agent of transmission, and even calcification but are important to the development of larva of the parasite. 4|Page J.M.J.R. HARD PITTING OR BRAWNY EDEMA OF FILARIASIS: ELEPHANTIASIS increased permeability of lymph vessel walls leads to Delayed sequel to repeated lymphangitis, obstruction leakage of protein-rich lymph into the tissues and lymphedema. There is non-pitting brawny edema with growth of new adventitious tissue and thickened skin, cracks, and fissures with secondary bacterial and ACUTE FILARIAL DISEASE fungal infections. Lower limbs are commonly affected Adenolymphagitis (ADL) or but upper limb and male genitalia may be involved, Dermatolymphangioadenitis (DLA) breast and genitalia of females may be affected but Characterized by sudden onset high grade fever with relatively uncommon. rigors and last for 2 or 3 days, lymphatic Disabling and disfiguring edema of the limbs, the inflammation (lymphangitis and lymphadenitis), and breast and genitals accompanied by the thickening of transient local edema. the skin Lymphatics of the testes and spermatic cord are - Accumulation of lymph fluids, causing cracks and frequently involved, with epididymo-orchitis and wounds because of the thickening and drying of funiculitis. the skin Lymphadenitis: inflammation of the lymph nodes. - Possible to accumulate bacterial infection The most commonly affected are the inguinal nodes HYDROCOELE followed by the axillary nodes. The lymph nodes Accumulation of fluid occurs due to obstruction of become painful and tender. lymph vessels of the spermatic cord and also by Lymphangitis: inflammation of the lymph vessels; exudation from the inflamed testes and epididymis. appear as red streaks underneath the skins; caused The fluid is usually clear and straw colored but may by the allergic or inflammatory reaction to the filarial sometimes be cloudy, milky, or hemorrhagic. infection [allergic reaction to worms] - Typically accumulates in the closed sac of the - Usually associated with streptococcal infection tests [scratching can lead to open skin or wound that - Chronic epididymitis, funiculitis, lymphadematus, can be a habitat for bacteria such as thickening of the spermatic cord – manifestations streptococcus] of chronic bacroftian filariasis caused by W. CHRONIC FILARIAL DISEASE bancrofti More commonly encountered than its acute form LYMPHORRHAGIA Lymphedema: follows successive attacks of Chylocele, milky appearance caused by the presence lymphangitis and usually starts as swelling around the of lymph, rupture of lymph varices leading to release ankle, spreading to the back of the foot and leg. It of lymph or chyle and resulting in chyluria (kidney may also affect the arms, breast, scrotum, vulva, or damage: “milky urine”), chylous diarrhea, chylous any other part of body. Initially, the edema is pitting ascites, and chycothorax, depending on the involved in nature, but in course of time, becomes hard and site. non-pitting. - Rupture of lymph vessels that cause the release - Pitting in nature: swollen part of the body looks of chylocele like a dimple after pressing for a few seconds EXPATRIATE SYNDROME Lymphoangiovarix: Dilatation of lymph vessels Occurs to migrants who got infected from endemic commonly occurs in the inguinal, scrotal, testicular, regions. and abdominal sites. - Once migrated or visit endemic areas of filariasis, The lymphangitis and lymphadenitis can involve both they can have immunologic hyperresponse to of your upper and lower extremities caused by both maturing worms of the bancroftian and brugian filariasis, but the It is characterized by clinical and immunologic involvement of the genitals occurs exclusively with hyperresponsiveness to the matured or maturing W. bancrofti infection. The genital involvement can worms. be in a form of foliculitis, epididymitis, and hydrocele Exhibits acute manifestations and allergic reactions formation. (hives, rashes and blood eosinophilia). 5|Page J.M.J.R.  OCCULT FILARIASIS [HIDDEN] Lymphatic ORGANS lymphatic vessels system, lung, Classical manifestations of filariasis are absent INVOLVED and lymph node liver, spleen, Synonyms: Weingartner's syndrome, Meyer's- Joints Kouwenaar syndrome, Pseudo-tuberculosis of the lung, Present in Eosinophilic pseudoleukemia, Tropical eosinophilic MICROFILARIA Present in the blood tissues, not in asthma and Frimödt-Möller and Barton syndrome the blood Hypersensitivity reaction to microfilarial antigens, not SEROLOGICAL Complement Complement directly due to lymphatic involvement. fixation test – not so fixation test – TEST Microfilariae are not found in blood, as they are sensitive highly sensitive destroyed by the tissues. THERAPEUTIC Prompt response No response RESPONSE to DEC Clinical manifestations: massive eosinophilia (30–80%), hepatosplenomegaly, pulmonary symptoms (dry nocturnal cough, dyspnea, and asthmatic wheezing) STAGING SYSTEM FOR CHRONIC LYMPHEDEMA Has also been reported to cause arthritis, [DREYER ET. AL 2002] glomerulonephritis, thrombophlebitis, tenosynovitis, etc. Stage 1: swelling increases during day but reversible once the patient lies flat in bed TROPICAL PULMONARY EOSINOPHILIA Stage 2: irreversible swelling Manifestation: low-grade fever, loss of weight, and Stage 3: presence of shallow skinfolds pulmonary symptoms Stage 4: knobs, lumps and protrusions Children and young adults are more commonly Stage 5: deep skin folds affected in areas of endemic filariasis including the Stage 6: mossy lesions with leaking of translucent fluid Indian subcontinent. Stage 7: foul-smelling infected area, patient is unable to There is a marked increase in eosinophil count (>3000 μm which may go up to 50,000 or more). adequately or independently perform activities of daily Chest X-ray shows mottled shadows similar to miliary living tuberculosis. It is associated with a high level of serum IgE and filarial antibodies. Serological tests with filarial antigen are usually strongly positive. The condition responds to treatment with Considered one of the most debilitating disease diethylcarbamazine (DEC). affecting the socio-economic factors of the patient’s life. DIFFERENCE BETWEEN CLASSICAL DIAGNOSIS AND OCCULT FILARIASIS MICROSCOPY CLASSICAL OCCULT WET SMEARS – demonstrate motile microfilariae FILARIASIS FILARIASIS THICK BLOOD SMEARS Hypersensitivity - Giemsa stain Due to adult and [intense allergic CAUSE - Demonstration of the microfilaria developing worms reaction] to - Most practical diagnostic procedure microfilia antigen Eosinophilic lymphangitis, BASIC LESION granuloma lymphadenitis formation 6|Page J.M.J.R.  DIFFERENCES IN MICROFILARIAE Parameter W. bancrofti B. malayi Mean length 290 222 (um) Cephalic space 1:1 2:1 or breadth Sheath affinity Unstained Pink to Giemsa Irregular and Body nuclei Regularly spaced overlapping Terminal nuclei None 2 nuclei Appearance in Smoothly or kinky blood film gracely curved KNOTT’S CONCENTRATION TECHNIQUE Anticoagulated blood (1 ml) is placed in 9 ml of 2% formalin (Reagent) and centrifuged 500 × g for 1 minute. The sediment is spread on a slide to dry thoroughly. The slide is stained with Wright or Giemsa stain and examined microscopically for microfilariae. NUCLEOPORE FILTRATION In the filtration methods used at present, larger volumes of blood, up to 5 ml, can be filtered through millipore or nucleopore membranes (3 μm diameter). The membranes may be examined as such or after staining, for microfilariae. DEC PROVOCATION TEST A small dose of diethylcarbamazine (2 mg per kg body weight) induces microfilariae to appear in peripheral blood even during day time. - Pro