تجميعات في البارا

1-parasites causing
external autoinfection only:


1- Entrobius. 2- Entamoebahistolytica. 3- Balantidiumcoli.


4- Giardia .





2-parasitescausinginternalautoinfectiononly:


* Capillariaphlippinensis.





3-parasitescausingbothexternal & internalautoinfection:


1- Hymenolepis nana.
2- Taenia solium. 3-
Strongyloides.


4- Cryptosporidium.




Parasitescausinganaemia?





1-Microcytichypochromicanaemia ( iron
deficiency anaemia) :


*Mechanism: repeted blood loss → depletion of iron stores
by bone marrow.





e.g, 1- Schistosoma haematobium (terminal haematuria)


2- Schistosoma mansoni & S. japonicum (
dysentery & bleeding intestinal polyps).


3- Hookworms
“ Ancylostoma duodenale & Necator” ( suction of blood by worms
& bleeding from previous sites of attachment).


4- Trichuris
& Trichostrongylus “heavy infection” (suction of


blood by worms).





2-Macrocytichyperchromicanaemia (megaloblastic) :





e.g, 1- Diphyllobothrium latum ( consumption
of Vit. B12).


2- Trichuris ( toxic effect on bone marrow).





3- Haemolyticanaemia:


1- Plasmodium spp.


2- Babesia microti & B.
divergens.


3- S. mansoni & Plasmodium ( hypersplenism).


4- African trypanosomes & P.
falciparum ( autoimmune haemolysis).





Aplasticanaemia :


1-
Leishmania donovani.


2-
African trypanosomes.













• Snail as anintermediatehostforTrematoda ?

Role of snail as anintermediatehost :





* In all Trematoda : Egg hatches in water → miracidium
penetrates the snail→ develops to
sporocyst → redia →
cercaria.





* Except in : 1- Heterophyes : egg is
swallowed by snail where hatching occurs.



2- Schistosoma
: No redia stage inside the snail.




• Ectopic lesions caused by Flukes (Trematoda) ?


·
Ectopic lesion :
lesion caused by Trematode adult or egg away from its
normal habitat.


І- Ectopic lesions
by adult fluke:


1- Fasciola:
Encysted metacercaria may reach skin , gastric; caecal or colonic wall →
develop to immature flukes.


2- Paragonimus:
Young flukes may migrate from the lung to liver ; spleen; lymph
nodes; genitalia ; muscles; intestinal wall or skin → cysts containing
adult worms.


ІІ- Ectopic
lesions by egg:


1- Heterophyes : Egg may reach blood &
passes as emboli to :


A- Brain: → cerebral infarction or haemorrage.


B- Lung: → pulmonary embolism.


C- Heart: → myocarditis .


2- Schistosomes : Egg may reach :


A- Brain: → cerebral infarction “ common in S. japonicum”.


B-
Spinal cord : →
paraplegia.


C-
Lung: → bilharzial core pulmonale.




• Parasitescausingmyositis? ( 5 T)


1- Tissue cestodes:



·
Cysticercosis ( cysticercus
cellulosae of Taenia solium).


·
Sparganosis ( sparganum of Spirometra).


·
Coenurosis ( coenurus cerebralis
of Multicepis).


·
Hydatid disease ( hydatid cyst of Echinococcus).


2- Trichinella spiralis.


3- Toxocara canis (visceral larva migrans).


4- Toxoplasma gondii.


5- Trypanosoma cruzi.


• Parasitescausingappendicitis?


1- Ascaris (erratic worms).


2- Entrobius.


3- Trichuris.


4- Entamoeba histolytica.


5- Balantidium coli.







• Parasitesthatcan be detected in urine?


1-
Schistosoma haematobium eggs.


2-
Wuchereria bancrofti microfilaria.


3-
Trichomonas vaginalis trophozoite.


4-
Hydatid
sand (ruptured renal hydatid cyst).


5-
Toxocara canis larva
(visceral larva migrans).


6-
Entrobius eggs &
adult females (ectopic lesion).


7-
Larvae
(maggots) of Sarcophaga; Musca & Fannia (urogenital myiasis).




• Parasitesthat can be detected in CSF?





І- Helminths : ( Nematode
larvae)


1- Toxocara canis
larva (visceral larva migrans).


2- Trichinella
spiralis larva (migration stage).


3-Strongyloides filariform larva ( in disseminated hyperinfection
syndrome in immunosuppression).


ІІ- Protozoa :


1- Naegleria fowleri trophozoites (amoeboid form).


2- Trypanosoma gambiense & T.
rhodesiense in cerebral invasion stage ( trypomastigote
form).


3- Toxoplasma tachyzoites (inimmunosuppression).










• Parasitesthat can inhabitbiliarypassages & gallbladder?





1-
Fasciola
gigantica & F. hepatica adult.


2-
Ascaris
(erratic worms).


3-
Giardia
trophozoites.


4-
Cryptosporidium
(inimmunosuppression
).


•Filariformlarva is the infectivestage of somenematodes; enumerate them
& mentionmode of infection in each.





1-
Ancylostoma duodenale( skin penetration –
transmammary).


2-
Necator( skin penetration).


3-
Strongyloides( skin penetration – external & internal
autoinfection).


4-
Ancylostoma braziliensis ; A. caninum & non-human Strongyloides → cutaneous
larva migrans( skin penetration).


5-
Filaria(skin penetration through insect bite) e.g;


*Wuchereria bancrofti...........................Culex.


*Brugyia malayi…………………………..Mansonia.


*Loa loa………………………………….Chrysops.


*Onchocerca volvulus…………………Simulium.


*Mansonella ozzardi& M.perstans.....Culicoides.


6- Trichostrongylus ( ingestion of filariform larva
with raw vegetables).


7- Dracunculus
medinensis(ingestion of filariform larva within Cyclops).













• Loffler’ssyndrome : “definition, causativeparasites; C/P & diagnosis” ?





*definition: It is verminous pneumonitis caused by
migrating larvae of some helminths.


* causative parasites:


1-
Schistosomes.


2-
Ascaris.


3-
Hookworms ( Ancylostoma duodenale & Necator).


4-
Strongyloides.


* C/P: fever; cough; expectoration; haemoptysis &
eosinophilia.


* diagnosis:


1-
Chest X- ray: milliary opacities in the lung.


2-
Sputum examination : larvae &
Charcot – Leyden crystals.


3-
Blood examination :
eosinophilia.




• Parasitesinfectingmanthroughmeatconsumption:

• Mention sex modes
of infection by parasites with examples;





1- Ingestion : (Oral route)e.g;


·
Ascaris “ ingestion
of raw vegetables contaminated with embryonated egg”.


·
Oxyuris “ soiled
fingers”.


2- skin penetration : e.g;


·
Direct skin
penetration: as Schistosomes
“ through skin penetration with furcocercous cercaria”.


·
Through insect bite :
e.g; Filaria; Leishmania & Plasmodium.


3-
Blood transfusion :
e.g; Plasmodium & Babesia.


5- Congenital
“Transplacental “: e.g; Toxoplasma &
Trypanosomes.


6- Sexual : e.g;
Trichomonas vaginalis.










• Parasites thatcan be detected in bloodfilm ?


І- Helminths :


1- Strongyloides filariform larva ( in disseminated hyperinfection in
immunosuppression).


2- Trichinella larva ( during migration stage).


3- Microfilaria of :


* Wuchereria bancrofti.


* Brugyia malayi.


* Loa loa .


* Mansonella persitans & ozzardi


ІІ- Protozoa :





1-
Plasmodium & Babesia.


2-
Trypanosoma gambiense & T. rhodesiense.


3-
Trypanosoma cruzi.


4-
Leishmania donovani & L. infantum.


5-
Toxoplasma .



















• Parasitesthatmaycausepruritusani“Perianalitching”:


1- Entrobius (migrating
female worms & egg deposition at the
perianal skin).


2- Taenia saginata (passage of
gravid segment through the anus).


3- Ascaris(allergic reaction due to passage of adult worm through
the anus).


4- Strongyloides ( externally
autoinfective filariform larvae → larva currens).







• Parasitesthatmayaffectbrain :





І- Helminths:


1- Schistosoma japonicum eggs.


2- Heterophyes eggs.


3- Cysticercus cellulosae (cysticercosis).


4- Hydatid cyst.


5- Sparganum of Spirometra
(sparganosis).


6- Coenurus cerebralis of Multiceps
(coenurosis).


7- Larvae of nematodes :


A-
Ascaris larva (visceral larva
migrans – like symptoms→meningism)


B-
Toxocara canis larva (visceral
larva migrans).


C-
Trichinella larva (migration
stage).


D-
Strongyloides filariform larva (
disseminated hyperinfection in immunosuppression).


8- Loa loa (heavy infection
after DEC therapy →meningoencephalitis).


ІІ- Protozoa:


1- Entamoeba histolytica (amoebic brain abscess).


2- Naegleria (PAM).


3- Acanthamoeba
(GAE).


4- Trypanosoma gambiense & T. rhodesiense (sleeping sickness).


5- Trypanosoma cruzi (meningoencephalitis).


6- Plasmodium falciparum (cerebral malaria).


7- Toxoplasma (encephalitis).





ІІІ- Arthropods:


*
Chrysomyia larvae (causing aural myiasis) may reach the brain.



















• Parasitescausinghyperpigmentation of
skin (3V):


1- Onchocerca volvulus (Sowda ).


2- Leishmania
donovani ( grayish discoloration of skin of face & hands →black fever).


3- Heavy
infestataion with Pediculus (Vagabond
disease).

























• Parasitescausingsplenomegaly :





1- Schistosoma mansoni.


2- Toxocara canis (visceral larva migrans).


3- Wuchereria bancrofti & B.malayi (tropical pulmonary eosinophilia).


4- Plasmodium ovale; vivax
&falciparum (hyperactive
malarial splenomegaly).


5- Leishmania donovani & infantum.


6- Trypanosome cruzi.

























■ Hyperinfection : definition; parasiticcauses & mechanism ?





•
Hyperinfection : means massive
increase in the worm burden (i.e. parasite number) within the host as a result
of uncontrolled internal autoinfection.


• Parasitic
causes :


1- Strongyloides stercoralis (Opportunistic
parasite):


*Mechanism: in immunosuppressed
individuals; most of rhabditiform larvae develop into filariform (infective) larvae in the
lumen of the intestine → penetrate intestinal mucosa → migrate through the lung
→ ascend along bronchial tree → coughed ; swallowed & develop into adult
worms (repeated internal autoinfection → hyperinfection).


2-
Capillaria philippinensis (virulent
parasite):


*Mechanism: in immunocompetent
individuals; untreated infection will result in embryonation of eggs in the
intestinal lumen→ hatch → infective larvae penetrate intestinal mucosa→ develop
to adult worms (repeated internal autoinfection → hyperinfection).













• Manmayact as a blind host
(dead-end) for some parasitic infections:





·
Blind
host: a host that can be infected but cannot
infect others.


·
Man
acts as a blind host in:





1-
All
tissue cestodes (Hydatid
disease; cysticercosis; sparganosis & coenurosis).


2-
Trichinella spiralis.


3-
Visceral & cutaneous larva migrans.


4-
Babesiosis (man –to –Tick infection does not occur
; but, man – to – man infection can occur by blood transfusion).










• Parasites
infecting man through skin penetration ?





A-
Cercaria: as Schistosomes.


B-
Sparganum larva:
as Spirometra mansoni & S. proliferum (when infected raw flesh of
frog or snake used as foments for skin wound).


C-
Filariform larva:
either through:





І- Direct skin
penetration: e.g;





1-
Hookworms
( Ancylostoma duodenale & Necator).


2-
Strongyloides.


3-
Ancylostoma
caninum ; A. braziliensis
& non-human Strongyloides (→
cutaneous larva migrans).





ІІ- Insect bite: e.g; all filaria ;














*Wuchereria
bancrofti...........................Culex.


*Brugyia
malayi…………………………..Mansonia.


*Loa
loa………………………………….Chrysops.


*Onchocerca
volvulus…………………Simulium.


*Mansonella
ozzardi& M.perstans.....Culicoides.


D-
Protozoa : (through arthropod
bite);


1- Leishmania ……………………..Sand
fly.


2- Trypanosoma
gambiense & T. rhodesiense…….Glossina.


3- Trypanosoma cruzi
……………. Triatoma.


4- Plasmodium
…………………….Female Anopheles.


5- Babesia…………………………..Hard
tick.





E- Arthropods: either:





1-
Larvae (maggots) of flies: e.g;


larvae of Hypoderma;
Dermatobia & Gastrophilus (Cutaneous myiasis).





2- Arthropod itself :
e.g;


і- Tunga
penetrans (chigger flea).


іі-
Sarcoptes scabiei (→ scabies).


ііі-
Demodex.



















• Parasites that may affect Lung :





І- Helminths:


1- Paragonimus
(adult).


2- Heterophyes (ectopic
egg).


3- Schistosomes
(ectopic egg or migrating schistosomula).


4- Hydatid cyst.


5- Migrating larva of
nematodes: e.g;


* Nematodes causing Loffler’s
syndrome (Ascaris; Hookworms & Strongyloides).


* Trichinella spiralis.


6- W.bancrofti & B. malayi
(tropical pulmonary eosinophilia).


ІІ- Protozoa:


1- E. histolytica (extraintestinal amoebiasis).


2- Acanthamoeba (primary lesion).


3- Leishmania donovani & L. infantum.


4- Toxoplasma.


5- Plasmodium falciparum (Acute pulmonary oedema).


6- Cryptosporidium (in AIDS patients).


7- Pneumocystis.


ІІІ- Arthropods:


• Dermatophagoides (house dust mites) → bronchial asthma.
















• Role of “flies” in transmission of parasitic diseases ?





І- Mechanical
transmission:(i.e. No
multiplication or developmental changes of parasite in the fly).


e.g; 1- Musca
: transmits H.nana; T.solium & Entrobius eggs.


2- Stomoxys :
transmits African Trypanosomes.





ІІ- Biological
transmission: (i.e. multiplication and/or developmental changes of
parasite in the fly).


e.g; 1- Flies
transmitting Filaria: (cyclodevelopmental transmission)





* Chrysops transmits Loa loa.


* Simulium transmits Onchocerca volvulus.


* Culicoidestransmit Mansonella ozzardi & M.perstans.


2- Flies transmitting protozoa :
(cyclopropagative transmission)





* Sand fly transmits
Leishmania


* Glossina transmits
Trypanosoma gambiense & T. rhodesiense

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