Hookworms of Human & Animals

Bunostomum:

Major Specie	Host	Location/Site	Distribution
B. phlebotomum	Cattle/Ruminant	Small intestine	Worldwide
Bunostomum trigonocephalum	sheep and goats

 

Identification

Gross:

·         Bunostomum is one of the larger nematodes of the small intestine of ruminants, being 1.0-3.0 cm long and characteristically hooked at the anterior end.

Microscopic:

·         The large buccal capsule bears on the margin a pair of cutting plates and internally a large dorsal cone.

Life Cycle:

Infection with the L₃ may be percutaneous or oral, only the former being followed by pulmonary migration. The prepatent period ranges from 1 to 2 month. (see canine hook worm’s life cycle)

Pathogenesis and Clinical Signs:

·         The adult worms are blood suckers

·         Infections by 100-500 worms will produce anaemia, hypoalbuminaemia, loss of weight and occasionally diarrhea. In calves, skin penetration of the larvae may be accompanied by foot stamping and signs of itching.

Diagnosis:

• Clinical History with epidemiology
• Clinical signs
• Coproscopy:

Treatment and Control:

• The prophylactic anthelmintic regimens practised for Ostertagia or Haemonchus are usually sufficient to control this parasite.
• Otherwise treatment of out­breaks should be accompanied by measures to im­prove hygiene, particularly with regard to the disposal of manure, and by the provision of dry bedding for housed or yarded animals

Aeriostomum

• Agriostomum vryburgi is a common hookworm of the large intestine of cattle and buffaloes in Asia and South America. Its life cycle is probably direct and its pathogenicity, although unknown, presumably de­pends on its haematophagic habits.

Hookworms in man:

• Two hookworms, Ancylostoma duodenale and Necator americanus, occur in man in the tropics.
• Their pathogenesis is similar to that of A. caninum, but transmammary infection does not occur.

Comparative life cycles of different species of Ancylostomatoidae super family:

1.      Traits	Ancylostoma	Bunostomum	Uncinaria
2.      Transmission	Peroral,transmammary, Transplcental, skin penetration.	Peroral,transmammary, Skin penetration.	Peroral, Transplcental,skin penetration.
3.      PPP	14-21 days	1-2 months	15 days

Superfamily Metastrongyloidea

• Most worms in this superfamily inhabit the lungs or the blood vessels adjacent to the lungs. The typical life cycle is indirect, and the intermediate host is usually a mollusc.
• They may be conveniently divided into three groups according to host; those occurring in pigs, in sheep and goats, and in the domestic carnivores.

Major Specie	F/H	I/H	Location/Site	Distribution
Metastrongylus apri (syn. Elongatus) M. salmi M. pudendotectus	Pig	Earthworms	Small bronchi and bronchioles, especially those of the posterior lobes of the lungs	Worldwide
Muellerius capillaris,	Sheep and Goat	snails and slugs	alveoli	Worldwide except for arctic and sub-arctic regions.
Proto-strongylus		snails.	small bron­chioles
Oslerus osleri	Domestic and wild dogs	Absent	Embedded in fibrous nodules in tracheal bifurcation and adjacent to bronchi.	Worldwide
Aelurostrongylus abstrusus	Cats.	Many mollusks	Lung parenchyma and small bronchioles	Worldwide
Crenosoma vulpis	Dogs and farmed foxes	Mainly land snails.	Trachea, bronchi, and bronchioles	Worldwide