Parasitology protosoology (protosoa),
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 ususal 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,
- correct sampling – right sample, with good method at right
time, sent in appropriate conditions to the lab that is able to
identify the parasit, good interpretation:
Knowledge of life cycle is principal
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 it
• Transient host – larves are developing in it but sexual
multiplication is not performed
• Helmints : egg - larva - (cyste) – adult worm
Protozoa :trofozoit - motile, cyste – non motile
- sexual multiplication - zygota
- asexual- schizonts, sporogons
Patogenesis
• Chronic infections
• Protosoa – In strong immunity reaction –
imunopathologic signs – symptoms
hypersensitivity, cross reacting antigens (tissue
devastation) and autoimunity
• Worms – mechanic, big, metabolism – direct
injury (elefantiosis)
- imunity and inflamation – indirect
immunopathological reaction
Imunity
• production of IgE
• Worms stimulates CD4Th lymfocytes – they
secrete IL-4, IL-5
• ADCC – via eosinophils and IgE – elimination of
worms – basic protein in granulesof eosinophils is
toxic for worms
• CD4 - activation of macrophages – elimination of
parasits = Production of granuloms in organs,
fibrosis, tissue devastation
• I.c. parasits activate cytotoxic lymphocytes –
interference of disseminations
How parasits escape human
immunity
• = chronicity
• In-borne nonspecific mechanisms – faibly efficient
• Specific mechanisms – antigenic mimicry – the
surface of the parasit is covered with host
antigens, komplexes of Ag-Ab, i.c.localisation of
parasits, antigenic variation during infection
• - size, motility, cover of albunim, extreme
production of antigen imunity overload,
imnosuression
Therapia
•
•
•
•
Less structutres
Toxic
Knowledge of the life cycle of parasit is primary
Eucaryotic cells of parasits – toxicita – selective
toxicity can be achieved by changes of the
molecule by metabolising of it in the body of
parasit, acumulation of the molecule in the body
of parasit
• Chronicity – long term therapy
• Tissue localisation, encystation
• Socioeconomic conditions, climatic factors
Stool for parasitological examination
• Macroscopy – blood, mucous, adult worms
• Microscopy - native smear - FS, iode – motility,
eggs of helmints, cysts of protosoa, ery, leu
• Concentration methods – separation of cysts of
protosoa and eggs of helmints from other material in
the stool
• Stainning - 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 - Entamoeba histolytica
Sputum - Ascaris lumbricoides, Strongyloides,
Urine - Schistosoma
Urogenital sample - Trichomonas
Blood - (malaria, trypanosomiosis, leishmaniosis, filariosis)
smear, thick drop - staining acc. Giemsa, HeO,
• Serum
Protosoa
• 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 – aesculape´s bat
• Nonsegmented body, adult worms living in the GIT diagnosis: identification of eggs in the stool (morphology of
eggs)
• Filariae – thin worms parasiting in eye, skin, tissues,
transmitted by insects. Larval stage - 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 cysticercosis, echinococcosis)
• Taenia solium, Taenia saginata, Diphylobotrium latum,
Echinococcus granulosus, Echinococcus multiloculare
Hymenolepsis nana
Trematodes • Usually hermafrodits (exception - Schistosoma)
• Need transient host (hosts)
• Fasciolopsis, Clonorchis, Paragonimus, Schistosoma
Nematodes -worms
• Enterobius vermicularis, Ascaris lumbricoides, Toxocara
canis,cati, Trichuris trichiura, Ancylostoma duodenale,
Strongyloides stercoralis, Trichinella spiralis, Wuchereria
bancrofti, Dracunculus medinensis – aesculape´s bat
• Nonsegmented body, adult worms living in the GIT diagnosis: identification of eggs in the stool (morphology of
eggs)
• Filariae – thin worms parasiting in eye, skin, tissues,
transmitted by insects. Larval stage - microfilariae penetrate
to blood and are transmitted by suckling insect
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
Dracunculus
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 cysticercosis, echinococcosis)
• Taenia solium, Taenia saginata, Diphylobotrium latum,
Echinococcus granulosus, Echinococcus multiloculare
Hymenolepsis nana
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
Intestinal,brain and UG protosoa
• entamoeba histolytica
• entamoeba coli
• giardia lamblia
• naegleria fowleri, acanthamoeba
• trichomonas vaginalis
Entamoeba histolytica
• definitive: human
• dg.trofosoits in stool, serology
• dysenteria – diarhea with blood
Naegleria fowleri, Acantamoeba
• Free Living in water
• Human (via nose)
• dg.microscopy in CSF- identification of invasive
strains)
• disease: purulent peracute meningitis
Trichomonas vaginalis
• Definitive: human
• transient: none
• dg. Cultivation - microscopy trophosoit from vagina, urine
• Sexual transmission
• Therapy of both (all) partners
Blood and tissue protosoa
•
•
•
•
Plasmodium vivax – tertiana
Plasmodium ovale – tertiana
Plasmodium malariae – quartana
Plasmodium falciparum – maligna tertiana
•
•
•
•
Toxoplasma gondii
Pneumocystis carinii – jiroveci
Leishmania donovani – kala azar
Trypanosoma brucei gambiense – sleeping disease
rhodesiense
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……..
Life cycle
• Cat swallow tissue cyst (in food) or oocyst (from
excrements)
– infection of epitelial cells of small intestin
– asexual and sexual multiplication – formation of
oocysts – excremetion during 1-2 weeks – cyst is
nonsporulated = not infectious
– outside the body after 1-5 days cysts sporulate –
infectious during months, resistent to desinfection,
freezing, drying, heating to 70 dg C for10 mins.
Clinical manifestation
• 1941 - Sabin – meningoencefalitída
•
- Pinkerton a Henderson – tyfoidné príznaky
• 1951 - Siim – generalised lymphadenopathy lymphocyto-monocytes proliferation in periferal blood
•
•
•
•
gained toxoplasmosis
gained or reactivated toxoplasmosis in IDS
In borne – congenital toxoplasmosis
Eye toxoplasmosis
Gained toxoplasmosis
• Usually asymptomatic
• 10% - 20% cervical lymphadenopathy +
flue like symptoms
• Clinicallly selfliminting – reactivation in
IDS, in gravidity
Gained toxoplasmosis in IDS
• Primary infection or reactivation of anamnestic
infection
• CNS , myocarditis, pneumonia
• AIDS pacients – encephfalitis, intracerebral lesions
Congenital toxoplasmosis
• In acute primoinfection of mother during pregnancy
• Symptoms depends on the lenghth of gravidity during
primoinfection
• Therapy can decrease the symptomatology
• Acute diagnosis is important
• New borne can have
- subclinical symptoms – without therapy usually getting
worse
- sy i.u. toxoplasmosis – hydrocefalus, calcifications in
brain and liver, cataracta, microcephalus
Eye toxoplasmosis
• Ofthen asymptomatic untill the 2nd-3rd
decenium
• Symotoms – rupture of the cyst in eye,
tachysoits and bradysoits are released
• Chorioretinitis
– unilateral – after gained infection
– bilateral – after i.u. infection
Toxoplasma gondii
protozoa i.c. parasit
• Infiects different warm-blood
annimals
• Cat is host for sexual stages of
Toxoplasmy gondii (schisonts)
– main source
• 3 stages
– tachysoits (trofosoits) – quick
multiplication and destruction of the
invaded tissue
– bradysoits – slowly multipliing in
tissue cysts
– sporosoits (male and female
gamonts) in oocysts – in cat
excrements
developmental stages of
Toxoplasma gondii
Neonsporulating adn sporulating
cyst from cat stool
Tachysoits free
and i.c.
Bradysoits in
tissue cysts
Infection in men
• 1) food borne with inappropriately boiled food
containing tissue cysts
• 2) transplantacentarly
• 3) accidentally by innoculation of tachysoits
• 4) swallowing of oocysts (sandy playgrounds.,
contaminated hands)
• 5) kontaminated trasfusion or transplantation
Pathogenesis
•
•
•
•
•
Swallowing of the cyst (bradysoit) or oocyst (sporosoit)
Releasing of microorganism
Invasion to the small intestin epitelium
Dissemination and multiplication intracelularly
Death of infected cells, releasing od tachysoits that invade
other cells
• Reaction of immunity system, change of tachy to
bradysoits, formation of tissue cysts (in muscles, heart,
brain)
• Reactivation during IDS – rupture of cysts, releasing of
parasits
Direct proof
•
•
•
•
•
•
•
Seldom positive
Staining acc. Giemsa
Immunofluorescence
ELISA for antigen detection
Tissue cultures
Innoculation of mouses
PCR
Laboratory results
IgG IgM specific antibodies:
–
– without serological proof
–
+ probable acute infection (+IgA from the same
sample) or false positive IgM
reaction (repetition of IgG and IgM
from neuw sample – no changes)
+
+ probable infection 6 – 12 mnths ago.
++
– probable infection 1 year ago
KFR – total antibody detection
CFR
titres above 8 are suspect for infection
dynamicity
– increase of the titre after 14 days - acute
– maps decrease of the infection after therapy and
possible reactiovation of the infection
CFR antibodies are life long persistent
Serology of toxoplasma gondi in
pregnancy
• I. trimestre
– test for IgM antibodies – detection of i.u. infection –
positivity – indicate recetn infection
current IgA positivity – acute infection – therapy of
mother and screening of the baby
• IgG antibodies positive (seldome with IgM positivity) –
not indicating acute infection, can result in reactivation of
possible tissue cyst, thah has no relation to pregnancy and
cannot be eliminated by therapy
• Increase of IgG antibodies – reactivation of past infection
without threat of fetus health
Antenatal diagnosis of inborne
toxoplasmosis
•
•
•
•
Acute infection in pregnant mother
Therapia
Ultra sonography
Amnionic fluid + fetal blood: PCR innoculation do
mouses and tissue cultures
• Fetal blood: Toxo IgM and IgA, activity of liver
ensyms
Newborne infection dg
• Isolation from placenta, umbilicus leucocytes
• Clinical and laboratory test for tissue injury
detection
• Špecific antibodies
– newborne
serum
CSF
– mother
serum
•
IgG,M,A
IgM,IgA
•
PCR
•
tachysoit
Sequelae of toxoplasma infection
in women
• primary infection – possibility of fetal death
– lethal infection of the fetus
• intrauterine infection and birth of ill baby
• Previous infection with cysts in tissue of
gential tract – problems with conception
and succesfull pregnancy (habitual
abortions)
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,