Flashcards of all parasites
in the course HUMAN
PARASITES
By Joke Stynen
1
Entamoeba
• Morphology
histolytica Protozoa:Intestinal amoeba
• Trophozoites: pseudopodia, nucleus, karysome, endoplasmatic intrusion
• Cysts: chromidial bodies, glycogen mass, metacyst has 4 nuclei
• Prevalence (geographical + type of person)
• Developping countries
• Location (body)
• Large intestines (and liver)
• Transmission
• Person-to person = anthroponotic
• Orofaecal → contaminated food/water
• (Homoxy) cycle
• Minutaform cycle: cyst → gut: excystation (1 cyst → 4 parasites)→ trophozoites in small intestine →
large intestine → rectum: minutaform → cysts → metacysts in environment
• Magnaform cycle (immunocompromised): trophozoite → magnaform → histolysin → bloodstream
→ liver → through diaphragm → lungs/ CNS → secondary entamoebiasis
• Symptoms
• Non-invasive luminal amoebiasis = minuta: asymptomatic, self-limiting, occasional resurgences
• Invasive luminal amoebiasis = magna: dysentery, colitis, toxic megacolon, amoeboma, megacolon
• Extra-intestinal amoebiasis: liver infection, peritonitis, secondary infection
• Diagnosis
• Coprology for trophozoites (trichome or HE) or cysts (iodine)
• PCR or ELISA (Ag-detection = best)
• RX, CT, MRI, ultrasound
• Treatment + prevention
• Luminal infection: asymptomatic → paromycin or iodoquinol/diiodohydroxyquin
• Systemic infection: symptomatic → emetine/dehyrdoemetine or chloroquine
• Luminal + systemic action: for symptomatic carriers → nitro-imidazoles
• Filtration or boiling drinking water, cooked food, washed vegetabels/fruit, good sanitation 2
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1
, Nigeria Fowleri and Acanthamoeba Castellani Protozoa:Opportunistic amoeba
• Morphology
• /
• Prevalence (geographical + type of person)
• Primary infection N. Fowleri: olfactory neuro-epithelial
• Primary infection A. Castellani: skin
• Location (body)
• CNS
• Transmission
• Human is incidental host
• Contaminated salt warm water (N. Fowleri) or all cold water (A. Castellani)
• Cycle
• /
• Symptoms
• N. Fowleri: PAM = primary amoebic meningo-encephalitis: infected CNS (poorly IS)
• A. Castellani: primary skin infection, then GAE =granulomatous amoebic encephalitis
• A. keratitis: eye infection → partial blindness
• Diagnosis
• /
• Treatment
• N. Fowleri: Difficult → needs to go through BBB; nitro-imidazoles
• A. keratitis: continuus nitro-imidazoles
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3
(Zie slide 38 voor benamingen)
Balantidum Coli Protozoa: Cileamoeba
• Morphology
• Trophozoites: cilia, vestibulum, macro- and micronucleus
• Genetic exchange strategy
• Prevalence (geographical + type of person)
• Tropical regions
• Location (body)
• Large intestines
• Transmission
• Contaminated water/food or zoonotic <pigs
• Cycle
• Uptake → excystation in GI tract (1cyst -> 1 trophozoite!) → transveral division → feed on
bacteria →rectum: cysts
• Malnutrition → hyaluronidase enzyme →invasive
• Symptoms
• (Invasive) balantiosis: dysentery → colitis with haemorrhagic diarrhea
• Diagnosis
• Analysis of stool sample → flotation of cysts
• Treatment
• Nitro-imidazoles
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2
, Giardia intestinalis/duodenalis/lamblia Protozoa: Muco-flagellates
• Morphology
• Trophozoites: 8 different flagella, 2 adhesive discs, 2 nuclei (1 cyst with 4 nuclei → 2
troph), median bodies
Trophozoite • Prevalence (geographical + type of person)
Cyst • Globoal but more in temperate and tropical zones
• Children (6-10y) , homosexuals, malnutrition, immunsuppressive, crowded conditions
• Location (body)
• Small intestines-duodenum (!more pathogenic)
• Transmission
• Zoonotic (beavere, cattle…) → !flood
• Direct: oral-faecal route → contaminated food/water
• Cycle
• Cysts → excystation in GIT → longitudinal division → rectum → cysts in environment
• Symptoms
• Mostly asymptomatic and self limiting
• Chronic (travelers) diarrhoea (with blood when invasive)), no fever, malaise, cramps ,
nausea, anorexia, steatorrhea
• Diagnosis
• Coprology on fresh stool sample or intestinal aspirates → trichrome/iodine/ HE stain
• Ag detection: Copro-ELIS, IF, PCR
• Treatment + prevention
• Metronidazole (nitro-imidazole) → DNA damage
• Filtration of drinking water, boiling food/water, good sanitation, no human mest as fertilizer
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5
Trichomonas vaginalis Protozoa: Muco-flagellates
• Morphology
• No cysts
• Axostyle, 5 flagella, undulating membrane
• Prevalence (geographical + type of person)
• Global
• Male and female (STD), frequent with HIV, gonorrhoea, chlamydia
• Urogenital tract
• Location (body)
• Small intestines-duodenum
• Transmission
• Direct: human-to-humann
• (Homoxene) Cycle
• Sexual intercourse → throphozoite → urogenital tract → thrive in vaginal tract
• Symptoms
• Females: vulvo-vaginitis or urethritis: vaginal discharge, itch, burn, secodnary infections
• Males: 50% asymptomatic
• Diagnosis
• Demonstration of trophozoites in vaginal mucus (wet smear)
• Treatment
• Metronidazole (topical for woman and systemic for man) for all partners
6
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3
, • Morphology
Trypanosoma brucei rhodesiense • Flagellum, kinetoplastid, undulating membrane, nucleus
Protozoa: Kinetoplastids
• Prevalence (geographical + type of person)
• East-Africa
• Males
• Location (body)
• Blood circulation, brain
• Transmission
• Zoonotic(not person-to-person!): wild and domestic animal reservoirs (cattle)
• Vector: Glossina morsitans (tsetse fly)
• Cycle
• In human trypomastigotes:
• In colonization stage : binary fission, migrate to lymph nodes/brains
• Pre-adapted to be accomodated in tsetse
• Tsetse feed on human → parasites taken up → midgut → trypomastigotes →salivary glands → epimastigotes
→ metacyclic trypomastigotes → infection of new host when it feeds
• Symptoms
• East-African or Rhodesian sleeping sickness: acute sleeping sickness
• LOCAL reaction on inoculum site: inoculation chancre (Winterbottom sign)
• SYSTEMIC spread in the blood and lymph nodes: stage 1: haemolymphatic stage
• CEREBRAL spread: stage 2: encephalitic (after1-few months), cross BBB and cause IFγ mediated inflammation
• Diagnosis
• Clinical: winterbottom sign (swollen lymph nodes), apathy, neurological
• Parasitological: lymph node aspirate, cerebrospinal fluid (stage 1 or 2)
• Serological: CATT (card agglutination test for trypanosomiasis) test
• Treatment + control/prevention
• Active case detection, vector control (insecticides, debushing, sterile insect techniques, traps)
• 1ste stage: IV Suramin → inhibition of glycolysis
• 2nd stage: IV Melarsoprol → inhibition of glycolysis 7
7
• Morphology
Trypansoma brucei gambiense • Flagellum, kinetoplastid, undulating membrane, nucleus
Protozoa: Kinetoplastids
• Prevalence (geographical + type of person)
• West-Africa
• Females
• Location (body)
• Blood ciruclation, brain
• Transmission
• Anthroponotic
• Vector: Glossina palpalis: riverine species
• Cycle
• In human trypomastigotes:
• In colonization stage : binary fission, migrate to lymph nodes/brains
• Pre-adapted to be accomodated in tsetse
• Tsetse feed on human → parasites taken up → midgut → trypomastigotes →salivary glands → epimastigotes
→ metacyclic trypomastigotes → infection of new host when it feeds
• Symptoms
• West-African or Gambian sleeping sickness: chronic sleeping sickness
• LOCAL reaction on inoculum site: inoculation chancre (Winterbottom sign)
• SYSTEMIC spread in the blood and lymph nodes: stage 1: haemolymphatic stage
• CEREBRAL spread: stage 2: encephalitic, parasites cross BBB and cause IFγ mediated inflammation
• Diagnosis
• Clinical: winterbottom sign (swollen lymph nodes), apathy, neurological
• Parasitological: lymph node aspirate, cerebrospinal fluid (stage 1 or 2)
• Serological: CATT (card agglutination test for trypanosomiasis) test
• Treatment
• Active case detection, vector control (insecticides, debushing, sterile insect techniques, traps)
• 1st stage: IM Pentamidin → inhibition of dihydrofolate-reductase
• 2nd stage: IV Eflornithine (NECT) → inhibition of ornithine-decarboxylase, susceptible to ROS 8
• New: oral Fexinidazole (nitro-imidazole)
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