LEISHMANIA BRAZILIENSIS Amastigote and promastigote forms Shape: Oval Vector: mosquito Animal source: small rodent animals.
Leishmania donovani
Trypanosoma
Cyclical transmission :The arthropod is necessary intermediate host in which the Trypanosoma multiply . Non –cyclical transmission (interrupted feeding of biting insects) . The try do not multiply and die quickly so cross transmission is only possible for a few hours .
Salivarian Species T. brucei affects all domestic mammals including small and farm species and humans. It also causes a specific skin disease in donkeys. T. vivax infects ruminants, horses and camels causing significant disease. T. equiperdum causes venereal equine disease dourine. It is the only trypanosome that does not immediately require an insect vector for transmission, being spread through coitus.
T. simiae causes fatal pyrexia in pigs while T. congolense is milder in the same species. T. congolense can also affect dogs and cats causing acute fever, anaemia and neurological signs. T. evansi also affects all domestic mammals.
Stercorarian Species T. cruzi occurs in South America where it is transmitted by a triatomid (kissing) bug and infects armadillos, possums and humans. It is known as Chagas ’ Disease. A similar acute disease is thought to be caused by T. cruzi in dogs in the USA.
T. melophagum and T. theileri are non-pathogenic species present in the UK infecting cattle, buffalo and antelope. Stress and concurrent disease are thought to be contributors to the development of clinical disease from T. theileri .
Intestinal flagellates Giardia lamblia -the only pathogenic intestinal flagellates affecting the small intestine of man especially the children from 6-10 years old. -it is known to cause epidemic, endemic or traveler’s diarrhea through the world.
It is pear-shaped bilaterally symmetrical about 15x8um convex dorsally & flat ventrally with 2 suction discs containing two oval nuclei 2 longitudinal axostyles crossed by 2 parabasal bodies & 4 pairs of flagella.
ovoid about 12 x 8 µm has a well defined cyst wall. It has a granular cytoplasm containing 4 nuclei at one pole, axostyles , parabasal bodies and remnants of flagella.
Genitourinary flagellate Trichomonas vaginalis -- exists only as a trophozoite stage.