Ostertagia ostertagi: Establishment of patent infections in calves by intravenous inoculation

Williams, Justin; Roberts, ED; Todd, J

doi:10.1016/0020-7519(74)90009-5

Cited by 10 publications

(4 citation statements)

References 5 publications

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“…However, this consideration was only made prior to the appearance of infective L 3 larvae arising from eggs deposited by the calf population. The time to earliest appearance of egg-producing adult female worms within the host population, and hence eggs deposited onto pasture, was assumed to be 17 days (Williams et al 1974 ). The proportion of eggs that develop into infective L 3 larvae was assumed to be 0·15 (Young and Anderson, 1981 ).…”

Section: Methodsmentioning

confidence: 99%

A stochastic model to investigate the effects of control strategies on calves exposed toOstertagia ostertagi

et al. 2016

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SUMMARYPredicting the effectiveness of parasite control strategies requires accounting for the responses of individual hosts and the epidemiology of parasite supra- and infra-populations. The first objective was to develop a stochastic model that predicted the parasitological interactions within a group of first season grazing calves challenged by Ostertagia ostertagi, by considering phenotypic variation amongst the calves and variation in parasite infra-population. Model behaviour was assessed using variations in parasite supra-population and calf stocking rate. The model showed the initial pasture infection level to have little impact on parasitological output traits, such as worm burdens and FEC, or overall performance of calves, whereas increasing stocking rate had a disproportionately large effect on both parasitological and performance traits. Model predictions were compared with published data taken from experiments on common control strategies, such as reducing stocking rates, the ‘dose and move’ strategy and strategic treatment with anthelmintic at specific times. Model predictions showed in most cases reasonable agreement with observations, supporting model robustness. The stochastic model developed is flexible, with the potential to predict the consequences of other nematode control strategies, such as targeted selective treatments on groups of grazing calves.

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Section: Methodsmentioning

confidence: 99%

A stochastic model to investigate the effects of control strategies on calves exposed toOstertagia ostertagi

et al. 2016

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“…We can only speculate as to the in which way, after percutaneous entry into the host's body, O. dentatum larvae migrate to settle as mature worms in the large intestine. Williams et al (1974) sug- Table 1 Fecal egg counts and worm recovery from the large intestines of pigs inoculated in experiment I via dierent infection routes with 10,000 infective L 3 of Oesophagostomum dentatum at 36 and 10 days before necropsy, respectively (EPG Eggs per gram of feces; Fe, Ma, L 4 adult females, adult males, and fourth-stage larvae, respectively; IT/OT percutaneous inoculation performed by exposure of the skin on the inner/outer thigh to L 3 ; IV intravenous inoculation; Control oral administration of L 3 for assessment of worm establishment) Our studies may suggest a similar route of migration of nodular worms in the pig. However, another possibility could be that the larvae used a lymphatic pathway, thereby circumventing the liver and lungs and instead migrating directly to the wall of the large intestine to establish in nodules prior to their entry into the intestinal lumen.…”

Section: Discussionmentioning

confidence: 97%

“…The migratory route from the site of skin penetration to the gut is unknown, but transport via the bloodstream could be a possibility; e.g., Williams et al (1974) found that patent Ostertagia ostertagi infections in calves could result from intravenous inoculation with infective larvae.…”

Section: Introductionmentioning

confidence: 99%

A study on the establishment of Oesophagostomum dentatum in pigs following percutaneous exposure to third-stage larvae

Nosal

Çhristensen²,

Nansen³

1998

Parasitology Research

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We examined the possibility of establishment of patent infections after percutaneous exposure of parasite-naive pigs to 10,000 Oesophagostomum dentatum infective larvae (L3). At 5 weeks after percutaneous exposure the pigs were slaughtered and low numbers of adult O. dentatum were recovered from the large intestine. In addition, exsheathed L3 were intravenously injected into pigs, which resulted in the recovery of fourth-stage larvae (L4) from nodules in the lungs as well as of L4 and adult worms from the large intestine. This study demonstrates the ability of porcine nodular worms to establish in the large intestine when pigs have been exposed percutaneously to infective larvae. It is possible that the larvae reach the large intestine by invading blood veins or the lymphatic system at the site of penetration.

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“…However, attempts to vaccinate calves against O. ostertagi have been unsuccessful so far (Btirger et al, 1968;Williams et al, 1974;Herlich and Douvres, 1979;Herlich and Tromba, 1982;Hilderson et al, 1995). To search more efficiently for future vaccines and to develop integrated control systems that allow acquisition of immunity, a better understanding of the development of immunity to O. ostertagi is required.…”

Section: Introductionmentioning

confidence: 99%

The effect of truncated infections with Ostertagia ostertagi on the development of acquired resistance in calves

Claerebout

Hilderson

Meeus

et al. 1996

Veterinary Parasitology

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The relative contribution of the third (L3), fourth (L4) and adult stages of Ostertagia ostertagi to the development of immunity was assessed in calves which were either continuously infected during 21 weeks or subjected to infections truncated by anthelmintic treatment at the L 3 or L 4 stage. A fourth group remained uninfected (control group). Faecal samples and blood samples were collected weekly for faecal egg counts and determination of pepsinogen and antibody levels. Only the continuously infected animals showed positive egg counts, which fell towards the end of the primary infection period. Pepsinogen and antibody levels remained high in the continuously infected group until the end of the primary infection period. At that time, they were significantly higher compared to the control calves, with intermediate values in the truncated infection groups. After the 21 weeks primary infection period all animals were dewormed. To evaluate the protection provided by the different immunisation protocols, all animals were challenged l week later with 156000 Ostertagia L 3, spread over 12 consecutive days. The marked reduction in egg counts following challenge infection indicated a certain degree of immunity in the continuously infected calves, which was confirmed at necropsy by the reduced worm burdens, the high percentage of inhibited early L 4 larvae, the reduced size of the adult worms and the higher numbers of mucosal mast cells in this group. Numbers of globule leucocytes and eosinophils were not significantly different from the control group. Infections truncated by anthelmintic treatment elicited poor development of immunity as shown by the egg output after the challenge infection Claerebout et al./ Veterinary Parasitology 66 (1996) 225-239 and the percentages of arrested larvae and the lengths of adult worms which were intermediate to those of the continuously infected calves and control animals.

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Ostertagia ostertagi: Establishment of patent infections in calves by intravenous inoculation

Cited by 10 publications

References 5 publications

A stochastic model to investigate the effects of control strategies on calves exposed toOstertagia ostertagi

A stochastic model to investigate the effects of control strategies on calves exposed toOstertagia ostertagi

A study on the establishment of Oesophagostomum dentatum in pigs following percutaneous exposure to third-stage larvae

The effect of truncated infections with Ostertagia ostertagi on the development of acquired resistance in calves

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