Evidence that primary infection of Charollais sheep with Toxoplasma gondii may not prevent foetal infection and abortion in subsequent lambings

Article English OPEN
Morley, EK ; Williams, RH ; Hughes, JM ; Thomasson, D ; Terry, RS ; Duncanson, P ; Smith, JE ; Hide, G
  • Publisher: Cambridge University Press
  • Related identifiers: doi: 10.1017/S0031182007003721
  • Subject: other | QH301
    mesheuropmc: respiratory system | parasitic diseases | animal diseases

A study carried out on a sheep farm examined whether Toxoplasma gondii foetal infection and associated abortion occur in successive lambings. We identified 29 ewes that gave birth to lambs on at least 2 successive years over our study period,2000–2003. Tissue samples from the progeny of these ewes were analysed by PCR to determine infection status with T. gondii. T. gondii-infected lambs were born in 31% of successive pregnancies. T. gondii-positive lambs were aborted in successive pregnancies in 21% of lambings during study period, 2000–2003. The frequency of successive abortions within this flock over the period 1992–2003 was 18%. If a lamb was congenitally infected there was a high risk (69%) that the successive lamb from that ewe would also be congenitally infected. Similarly, if a lamb was aborted there was a high risk\ud (55%) of abortion in the next lamb produced. These data suggest that life-long immunity to T. gondii infections may not always be acquired following an initial infection and raises the question as to whether the mechanisms of T. gondii transmission prior to and during ovine pregnancies are fully understood.
  • References (24)
    24 references, page 1 of 3

    Avelino, M. M. and Campos, D., Jr. (2002). Pregnancy as a risk factor for acute toxoplasmosis seroconversion. European Journal of Obstetrics and Gynecology and Reproductive Biology 4417, 1-6.

    Beverley, J. K. A., Watson, W. A. and Payne, J. M. (1971). The pathology of the placenta in ovine abortion due to toxoplasmosis. Veterinary Record 88, 124-128.

    Boothroyd, J. C. and Grigg, M. E. (2002). Population biology of Toxoplasma gondii and its relevance to human infection: do different strains cause different disease? Current Opinion in Microbiology 5, 438-442.

    Boyer, K. M., Remington, J. S. and MacLeod, R. L. (1998). Textbook of Pediatric Infectious Diseases, W.B. Saunders Company, Philadelphia, USA.

    Buxton, D., Rodger, S. M., Maley, S. W. and Wright, S. E. (2006). Toxoplasmosis : The possibility of vertical transmission. Small Ruminant Research 62, 43-46.

    Buxton, D., Maley, S. W., Wright, S. E., Rodger, S., Bartley, P. and Innes, E. A. (2007). Toxoplasma gondii and ovine toxoplasmosis : New aspects of an old story. Veterinary Parasitology 149, 25-28.

    Buxton, D. and Innes, E. A. (1995). A commercial vaccine for ovine toxoplasmosis. Parasitology 110, 11-16.

    Desmonts, G., Naot, Y. and Remington, J. S. (1981). Immunolglobulin M-immunosorbent agglutination assay for diagnosis of infectious diseases : diagnosis of acute congenital and acquired Toxoplasma infections. Journal of Clinical Microbiology 14, 486-491.

    Dubey, J. P. and Beattie, C. P. (1988). Toxoplasmosis of Animals and Man. CRC Press, Boca Raton, Florida, USA.

    Duncanson, P., Terry, R. S., Smith, J. E. and Hide, G. (2001). High levels of congenital transmission of Toxoplasma gondii in a commercial sheep flock. International Journal for Parasitology 31, 1699-1703.

  • Metrics
    views in OpenAIRE
    views in local repository
    downloads in local repository

    The information is available from the following content providers:

    From Number Of Views Number Of Downloads
    University of Salford Institutional Repository - IRUS-UK 0 65
Share - Bookmark