Parasitology
lab-12(trichinella+wuchereria)
1- Trichinella spiralis:
1-life cycle :: swine eat uncooked garbage containing pork scraps adult worm in
intestine of swine larva encysted in striated muscles of swine , bear , walrus man
eat raw or undercooked park adult warm in man intestine produce larva larvae
carried in blood stream to muscles and other organs larvae encysted in striated
muscles
2- larva survive only in skeletal muscles but in other locations will destroyed
3- larva with calcified capsule can be recognized by the eye not by X-ray
4- adult have spear ( )رمحprojection in the end of the mouth that allow deep
penetration in the muscles
5- the larva surround itself by cyst that developed in the skeletal muscles
6- man is the dead end of the cycle
7- it is intestinal nematode
8- man acquired the infection by ingest the infected meat which contain larva
9- infective stage larva
10- diagnostic stage First stage-larva in the nest cells
11- site : from duodenum to the end of intestine
12- female is viviparous that mean it give larva directly without egg ( in 2 days)
:::Note ::: oviparous give egg ---- viviparous give larva directly without egg
13- early stage of disease diarrhea
14- late stage of disease generalized muscle pain
15- muscles affected by this parasite :: diaphragm - Gastrocnemius – deltoid – calf
muscles – extraocular muscles
16- man is intermediate host ( because contain larva stage ) and definitive host (
because contain adult stage ) …… pig ,dog ,cat and other animals also intermediate and
definitive host ….. birds only definitive hosts………………man also act as harbor .
17- diagnosis the best method is muscle biopsy (100% result)….. other methods :
serological test(ELISSA) , skin test and see larva by naked eye ( adult male and female
rarely seen )
18- treatment barbiturate – corticosteroids – thiabendazole
2- Wuchereria bancrofti :
1- habitat large lymph vessels and lymph nodes
2- female : 8-10 cm …. Larger than male
3- human acquired the infection by bite of all species of mosquito … most common
species are : culex , aedes and anophyles
4- life cycle : female lay microfilariae in the lymphatic of man microfilariae penetrate
the lymphatic and migrate to the blood vessels and enter the circulation microfilariae
ingested by mosquito microfilariae penetrate the small intestine of mosquito then
migrate to the thoracic muscles where they develop infective larva in the proboscis
of the mosquito larva deposited on skin near bite of mosquito go to blood larva
enter lymphatic and developed to adult ( from 6 months to 1 year )
5- infective stage larva from mosquito (filariform larva L3)
6- diagnostic stage microfilariae
7- microfilariae = prelarval stage ( the number of microfilariae in night is 3 times more
than day ) in the day the microfilariae go to the pulmonary and in night it go to the
blood
8- female are viviparous
9- first stage asymptomatic
10 –second stage go to lymph nodes of lower limbs and external genitalia cause
lymphangitis and cause elephantiasis
11- after death of Wuchereria bancrofti it also cause disease by its toxin
::: note ::: microfilariae present in the blood of human then converted to larva in the
mosquito then to adult worm in the human ((
human is definitive host
))
12- diagnosis : 1- blood film ( taken at night because number of microfilariae is
increased )
2- blood centrifuge ( if blood film is negative )
3- calcified cyst seen by naked eye