Giardiasis Life Cycle

Microparasite = Small, unicellular, multiplies within vertebrate host Macroparasite = Large, multicellular, no direct reproduction within vertebrate host Ectoparasite = Live on the surface of the body Endoparasite = Live within the body of the host

Protozoa = Microparasites Helminths = Macroparasites Viruses = Excluded from the term 'parasite' Bacteria = Excluded from the term 'parasite'

Infection = Invasion by endoparasites Infestation = Infection by ectoparasites Parasitology = Study of organisms dependent on others for life cycle and metabolic needs Medical parasitology = Deals with parasites infecting man and related diseases

Ectoparasites = Transmitting pathogenic microorganisms Endoparasites = Not involved in transmitting pathogens Viruses = Excluded from parasite vectors Bacteria = Excluded from parasite vectors

Obligate parasites = Organisms cannot exist without a host Facultative parasites = Organisms may live either as parasites or free-living Accidental parasites = Organisms that attack an unusual host Aberrant parasites = Organisms that attack a host where they cannot develop further

Definitive host = Harbors the adult parasite and allows sexual replication Intermediate host = Harbors larval or asexual stages of a parasite Paratenic host = Host in which parasite larvae survive but do not develop further Reservoir host = Host that can harbor a pathogen indefinitely with no ill effects

Symbiosis = Association where both host and parasite are dependent on each other Commensalism = Association where only the parasite benefits without harming the host Parasitism = One partner (parasite) harms or lives at the expense of the other (host) Compromised host = Host with impaired defense mechanisms, highly susceptible to pathogens

Sarcomastigophora = Contains amoeba and flagellates Apicomplexa = Contains Sporozoa Ciliophora = Contains Ciliates Microspora =

Trophozoites = Active, feeding form of the parasite Cysts = Dormant, infective form of the parasite Excystation = Process where the cyst wall is lysed, releasing trophozoites Encystation = Process where chromatin material is concentrated into cysts

Large Intestine = Where trophozoites grow and multiply by binary fission Liver = Where trophozoites from the ulcer in the large intestine multiply, causing liver abscesses Small Intestine = Where metacystic trophozoites are carried into the caecum in the faecal stream Mucosa and Submucosa = Habitat of trophozoites in the large intestine

Amoebic Dysentery = Symptom of profuse bloody diarrhea caused by E.histolytica Amoebic Hepatitis = Result of trophozoites gaining entrance into radicles of portal vein and multiplying in the liver Amoebomas = Pseudotumoral lesions associated with necrosis, inflammation, and oedema caused by E.histolytica Hepatic Amoebiasis = Development of liver abscesses due to multiplication of trophozoites in the liver

Virulence of Strain = Determines how aggressive the infection will be Resistance of Host = Dependent on innate immunity, affects susceptibility to infection State of Nutrition = Can influence how well the host can fight off the infection Infection with Other Agents = Can make a host more or less susceptible to infection

Fever, Chills, and Diarrhea = Common symptoms experienced after E.histolytica infection Abdominal Discomfort or No Symptoms = Some individuals may have mild or no symptoms at all Bloody or White Mucus in Diarrhea = Indication of a more severe infection Symptoms Starting 2 or More Weeks After Infection = Delayed onset of symptoms after being infected

Microscopic identification = Common method for diagnosing E.histolytica Blood examination = Shows moderate leukocytosis Serological tests = In later stages of invasive amoebiasis, antibodies appear Histology = Trophozoites can be identified in aspirates or biopsy samples obtained during colonoscopy or surgery

Paromomycin = Drug of choice for asymptomatic infections Metronidazole = Drug of choice for symptomatic intestinal or extraintestinal infections Iodoquinol = Drug immediately followed by treatment with paromomycin or iodoquinol Tinidazole = Drug immediately followed by treatment with paromomycin or iodoquinol

Entamoeba dispar = Smaller in size compared to E.histolytica Entamoeba hartmanni = Contains a large glycogen vacuole that stains darkly with iodine Entamoeba coli = Both the trophozoite and cyst have one nucleus with a large endosome Endolimax nana = Mature cysts contain 4 nuclei

Found in warm freshwater and soil near warm-water discharges = Opportunistic amoeba causing naegleriasis Inhaled through the nose, entering nasal and olfactory nerve tissue = Pathogenic form is the invasive stage of the parasite Does not form a cyst in human tissue, only amoeboid trophozoite stage exists = Cysts and flagellate forms never found in tissues or CSF Causes rapidly fatal infection known as primary amoebic meningoencephalitis = Patient develops severe frontal headache, fever, and signs of meningeal irritation

Excystation = Release of trophozoites in the large intestine Encystation = Formation of resistant cysts in the life cycle Binary fission = Multiplication of trophozoites in the duodenum Division of nucleus = Mitotic division of the nucleus in Trichomonas vaginalis

General Stool Examination (GSE) = Identification of cysts in formed stool and trophozoites in diarrheal stool ELISA = Detection of anti-Giardia antibodies in patients' serum Entero test (string test) = Specimen aspiration from the upper intestine using a gelatin capsule with a nylon string Biopsy = Confirmation of giardiasis diagnosis through examination of duodenal and jejunal tissues

Metronidazole = Antibiotic causing nausea Tinidazole = Effective single-dose treatment for giardiasis Furazolidone = Popular option for treating giardiasis in children Antibiotics = Common treatment for giardiasis

Giardia lamblia = Causes severe diarrhea of steatorrhea type Chilomastix mesnili = Non-pathogenic, often co-occurs with other parasites Trichomonas vaginalis = Flagellated parasite causing trichomoniasis Commensal parasite = Considered non-pathogenic

Steatorrhea = Symptom associated with severe diarrhea caused by Giardia lamblia Epigastric pain = Symptom commonly experienced with giardiasis Jaundice = May result from localization of parasite in biliary tract Flatulence = Symptom associated with giardiasis

Vaginal discharge = One of the signs and symptoms of trichomoniasis in females Irritation = One of the signs and symptoms of trichomoniasis in females Dysuria = Symptom that infected males are usually asymptomatic for Low abdominal discomfort = Symptom that infected females may experience

T.tenax = Species causing infection in a specific part of the body Pentatrichomonas hominis = Species found in the intestinal tract of human beings T.vaginalis = Species causing trichomoniasis in females

Microscopic examination = Most traditional method for diagnosing trichomoniasis Culture T.vaginalis isolation = Method that can be done on urethral and vaginal exudates Classic symptoms diagnosis = Not a reliable method due to symptom similarity with other STDs Laboratory diagnosis = Involves more than just relying on clinical symptoms

Nitroimidazole antibiotics = Effective treatment for curing trichomoniasis Metronidazole or tinidazole = Specific antibiotics used for treating trichomoniasis Chronic infections risk = Reduced by proper antimicrobial treatment Developing countries cases = Where accessing healthcare and facilities for treatment is challenging

Vector = An agent that transmits infection from one human host to another Reservoir host = A host that can harbor a pathogen indefinitely with no ill effects Trophozoite = The active feeding stage of a protozoan parasite Cyst = The dormant transmission stage of a protozoan parasite

Giardia lamblia = Intestinal flagellate with trophozoite and cyst stages Amoebae = Motile parasites found in CSF Amphotericin B = Toxic drug used as an antinaeglerial agent Mechanical vector = Type of vector that assists in transferring parasitic forms between hosts

N. fowleri cultivation method = Placing CSF on non-nutrient agar spread with bacteria Life cycle of Giardia lamblia = Consists of trophozoite and cyst stages Purpose of wet-mount preparation = To demonstrate motile amoebae in fresh CSF specimen Treatment for PAM = No satisfactory treatment available at present

Biological vector = Transmits pathogenic organism after development and multiplication Microscopy of CSF = Used to demonstrate motile amoebae in a simple wet-mount preparation Natural reservoirs = Hosts that elucidate complete life cycle of infectious diseases Axostyle and ventral disk presence = Characteristics of Giardia lamblia

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