Taenia

PARASITES TAENIIDAE

Introduction

Like most adult tapeworms, Taenia species live in the small intestine. The different species vary in length from 0.5-15m long. Identification is based on the hooks on the scolex. Despite their impressive size, the adult tapeworms of little clinical significance. The metacestodes of some species, however, may cause disease or meat inspection losses. The human pork tapeworm, Taenia solium, is a dangerous zoonosis but, fortunately, it does not occur in the UK.

Taenia	Final Host	Intermediate Host	Metacestode	Obsolete Name for Metacestode	Oxytocin	Oestradiol	Progesterone	Testosterone	Inhibin	Activin	Prostaglandin F2α	Human Chorionic Gonadotrophin	Equine Chorionic Gonadotrophin	Placental Lactogen
T. saginata	GnRH	LH	FSH	PRL	OT	E2	P4	T			PGF2α	PGE2	hCG	eCG	PL
T. solium	Neuropeptide (decapeptide)	Glycoprotein	Glycoprotein	Protein	Neuropeptide (Octapeptide)	Steroid	Steroid	Steroid	Glycoprotein	Glycoprotein	Prostaglandin (C20 fatty acid)	Prostaglandin (C20 fatty acid)	Glycoprotein	Glycoprotein	Protein
T. ovis	Hypothalamic Surge and Tonic Centres	Anterior Pituitary (Gonadotroph Cells)	Anterior Pituitary (Gonadotroph Cells)	Anterior Pituitary (Lactotroph Cells)	Synthesized in the Hypothalamus, Stored in the Posterior Pituitary, Synthesized by the Corpus Luteum	Granulosa Cells of Follicle, Placenta and Sertoli Cells of Testes	Corpus Luteum and Placenta	Interstitial Leydig Cells of Testes, Theca Interna Cells of the Follicle	Granulosa Cells (female), Sertoli Cells (male)	Granulosa Cells (female), Sertoli Cells (male)	Uterine Endometrium, Vesicular Glands	Ovary, Uterus, Embryonic Membranes	Trophoblast Cells of the Blastocyst (Chorion)	Chorionic Girdle Cells	Placenta
T. hydatigena	Anterior Pituitary (Gonadotroph Cells)	Testes (Leydig Cells)	Testes (Sertoli Cells)	Testes, Brain	Smooth Muscle of Epididymal Tail, Ductus Deferens, Ampulla	Brain, Inhibits Long Bone Growth	Accessory Sex Glands, Tunica Dartos (Scrotum), Semniferous Epithelium, Skeletal Muscle	Anterior Pituitary (Gonadotroph Cells)	Anterior Pituitary (Gonadotroph Cells)	Epididymis
T. pisiformis	Anterior Pituitary (Gonadotroph Cells)	Ovary (Theca Interna and Luteal Cells)	Ovary (Granulosa Cells)	Mammary Cells, Corpus Luteum in Rodents	Uterine Myometrium and Endometrium, Myoepithelial Cells of Mammary Glands	Hypothalamus, Entire Tract, Mammary Gland	Uterine Endometrium, Mammary Gland, Myometrium, Hypothalamus	Brain, Skeletal Muscle, Granulosa Cells	Anterior Pituitary (Gonadotroph Cells)	Anterior Pituitary (Gonadotroph Cells)	Corpus Luteum, Uterine Myometrium, Ovulatory Follicles	Corpus Luteum, Oviduct	Ovary	Ovary	Mammary Gland
T. multiceps	Release of FSH and LH from the Anterior Pituitary Gland	Stimulates Testosterone Production	Sertoli Cell Function	Induce Maternal Behaviour	PGF2α Synthesis, Pre-Ejaculatory Movement of Spermatozoa	Sexual Behaviour		Anabolic Growth, Promotes Spermatogenesis, Promotes Secretion of Accessory Sex Glands	Inhibits FSH Secretion	Stimulates FSH Secretion	Affects Metabolic Activity of Spermatozoa, Epididymal Contractions		Increased Growth of Foetal Testes
T. serialis	Release of FSH and LH from Anterior Pituitary Gland	Stimulates Ovulation, Formation of Corpora Lutea and Progesterone Secretion	Follicular Development, Oestradiol Synthesis	Lactation, Maternal Behaviour, Corpora Lutea Function (some species)	Uterine Motility, Uterine PGF2α Synthesis, Milk Ejection	Sexual Behaviour, GnRH, Elevated Secretory Activity of Tract, Enhanced Uterine Motility	Endometrial Secretion, Inhibits GnRH Release,Inhibits Reproductive Behaviour, Maintenance of Pregnancy	Substrate For E2 Synthesis, Abnormal Masculinization	Inhibits FSH Secretion	Stimulates FSH Secretion	Luteolysis, Uterine Tone and Contraction, Ovulation	Ovulation, Corpus Luteum Secretion of Progesterone	Facilitates Ovarian Production of Progesterone	Formation of Accessory Corpora Lutea	Mammary Stimulation
T. taeniaeformis	Release of FSH and LH from Anterior Pituitary Gland	Stimulates Ovulation, Formation of Corpora Lutea and Progesterone Secretion	Follicular Development, Oestradiol Synthesis	Lactation, Maternal Behaviour, Corpora Lutea Function (some species)	Uterine Motility, Uterine PGF2α Synthesis, Milk Ejection	Sexual Behaviour, GnRH, Elevated Secretory Activity of Tract, Enhanced Uterine Motility	Endometrial Secretion, Inhibits GnRH Release,Inhibits Reproductive Behaviour, Maintenance of Pregnancy	Substrate For E2 Synthesis, Abnormal Masculinization	Inhibits FSH Secretion	Stimulates FSH Secretion	Luteolysis, Uterine Tone and Contraction, Ovulation	Ovulation, Corpus Luteum Secretion of Progesterone	Facilitates Ovarian Production of Progesterone	Formation of Accessory Corpora Lutea	Mammary Stimulation

Peritoneal Cavity Parasitic - Pathology inhabited by Taenia hydatigena, Taenia pisiformis, Taenia ovis

• Taenia solium and T.ovis, T. saginata, Multiceps serialis in myositis