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Parasitology - protozoology (protozoa),
helmintology(worms),
enthomology(insects)• Laboratory diagnosis: - life cycle of parasits,
material v laboratory dg
• Protozoa – intestinal, genital, urinary, blood, tissue
• Worms - Helmints: Nematodes, Cestodes,Trematodes
• Ectoparasits: louse, ticks, flies – important as vectors
Diagnosis• Problematic, not ususals outside endematic areas• Nonspecific clinical manigestation• eosinophilia in helmintoses – not constant sign• Importance of history – personal, travellers, social, economic, food,
therapy• Conditions for successful dg: • - think on parasitosis,• - také a good sample – right sample, with good method at right time,
send it in appropriate conditions to the lab that is able to identify the parasit, good interpretation:
• Knowledge of life cycle is principal
Laboratory diagnosis• Usually based on morphology (mikroscopic) • Demonstration of the parasit in different stages of life cycle in
clinical material• Macroscopic examination of the sample (stool or tissue)• Microscopic examination – native smear, staining, concentration
method• Serology – detection of antibodies, detection of antigénu• Genetic probes - detection, identification• Cultivation• Animal model
Life cycle of parasits -terminology
• Complex life cycle – key to diagnosis• Host – hosts• Definitive host – parasit finishes the growing cycle and is
becoming adult in it• Not typical host - parasit cannot develop in in • Transient host – larves are developing in it and not sexual
multiplication is performed• Helmints : egg - larva - (cyste) – adult worm
Protozoa :trofozoit - motile, cyste – non motile - sexual multiplication - zygota - asexual- schizonts, sporogons
Stool for parasitological examination• Macroscopy – blood, mucous, adult worms• Microscopy - native smear - FS, iode – motility,
eggs of helmints, cysts of protozoa, ery, leu• Concentration methods – separation of cysts of
protozoa and eggs of helmints from other material in the stool
• Staining - identification – smear of native stool + hematoxylin eosin, trichrome
Other material acc.to clinical manifestation
• Perianal - Enterobius vermicularis• Sigmoidoscopy - Entamoeba histolytica• Duodenal aspiration - Giardia lamblia• Biopsia of abscesse of liver - Entameba histolytica• Sputum - Ascaris lumbricoides, Strongyloides, • Urine - Schistosoma • Urogenital sample - Trichomonas • Blood - (malaria, trypanosomiaois, leishmaniosis, filariosis)
smear, thick drop - staining Giemsa, HeO, • Serum
Protozoa
• Amoeba - Entamoeba histolytica, Entamoeba coli, Naegleria fowleri, Acanthamoeba, Endolimax nana
• Flagelata - Giardia lamblia, Trichomonas vaginalis, Leishmania, Trypanosoma
• Ciliata - Balantidium coli• Coccidia a Sporosoa - Cryptosporidium,
Blastocystis, Microsporidia, Plasmodia, Babesia,, Toxoplasma
Nematodes -worms• Enterobius vermicularis, Ascaris lumbricoides, Toxocara
canis,cati, Trichuris trichiura, Ancylostoma duodenale, Strongyloides stercoralis, Trichinella spiralis, Wuchereria bancrofti, Dracunculus medinensis - aesculapova palica
• Nonsegmented body, adult worms living in the GIT-e, - diagnosisa: identification of eggs in the stool (morphology of eggs)
• Filariae – tin worms parasiting in eye, skin, tissue, transmitted by insects. Larval form- microfilariae penetrate to blood and are transmitted by suckling insect
Cestodes -• Head - scolex, segmented body• Hermafrodit, male and female organs are present in every
segment - dif.dg. They have not GIT, absorbtion of food. Complex life cycle with transient host (sometimes - human – larval stage of cysticerkósis, echinococcosis)
• Taenia solium, Taenia saginata, Diphylobotrium latum, Echinococcus granulosus, Hymenolepsis nana
Trematodes -• Usually hermafrodits (ex Schistosoma)
• Need transient host
• Fasciolopsis, Clonorchis, Paragonimus, Schistosoma
Enterobius vermicularis
• Definitive host - human
• transient - none
• dg. – perianal sample – microscopy of eggs
• fecal oral transmission - autoinfection
Enterobius vermicularis
Ascaris lumbricoides
• Definitive host: human
• Larva migrans: intestin, colon - muc.membrane - blood- lung - cough - mouth - colon
• dg. Egg in stool
• Infection via contaminated food
• Symptoms acc.to localisation of the larva
Ascaris lumbricoides
Toxocara canis, cati
• Definitive host dog, cat
• Transient host: rat
• Human incidental: human (larves)
• dg. serology
• transmission: hand food
Taenia saginata
• Definitive: human
• transient: cattle
• dg. Segments in stool
• Transmission cysticercus in beef
Taenia solium
• Definitive: pig
• transient: rat
• incidental: human in small intestin
• dg. serology
• Contaminated food
Echinococcus granulosus
• definitive: dog• transient:sheep• incidental: human• dg serology• transmission: cyste in meat• infection: mechanic pressure from
expanded cyst, prolonged growing, rupture of the cyst and dissemination
Echinococcus granulosus
Entamoeba histolytica
• definitive: human
• dg.trofosoits in stool, serology
• dysenteria – diarhea with blood
Entamoeba histolytica
Naegleria fowleri, Acantamoeba
• Free Living in water
• Human (via nose)
• dg.microscopy in CSF- identification of invasive strains)
• disease: purulent peracute meningitis
Toxoplazma gondii• Definitive: cat• transient: rat• incidental: human• dg. serology KFR, IgA, IgG, IgM• transmission: food borne, hand, annimal• disease: - intrauterine primoinfection
- generalised lymfadenopathy, encystation in organs – abortion, eye……..
Trichomonas vaginalis
• Definitive: human
• transient: none
• dg. Cultivation - microscopy trophosoit - from vagina, urine
• Sexual transmission
• Therapy of both (all) partners
Giardia lamblia
• definitive: human – small intestin,dog, cat
• transient: non
• dg.microscopy – cysts and trophosoits in stool, transient in duodenal secretion
• Transmission contaminated food
• malabsorption
Giardia lamblia
Trypanosoma gambiensis (spavá choroba)
• Definitive host: insect - fly tse tse
• transient: human, monkey
• dg.microscopy – thick drop
• Transmission bite
• Disease – sleeping disease, myalgia, artralgia, lymfadenopathy, hyperactivity in acute fase, lethargy, meningoencefalitis, coma
Plasmodium-malariae, falciparum • Definitive host:Anopheles • Transient host: human, monkey• dg.microscopy thick drop• Transmission insect bite• disease: malaria acc.to the rate of schizogonia- clinically as
fever attacks - tercianna, quartana,