Toxoplasmosis in bovine

• Autor(a) principal: Dos Santos, Thaís Rabelo [UNESP]
• Data de Publicação: 2013
• Outros Autores: Dos Santos, Rodrigo Rabelo [UNESP], Da Costa, Alvimar José [UNESP], Bresciani, Katia Denise Saraiva [UNESP]
• Tipo de documento: Capítulo de livro
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/232247

Toxoplasma gondii is a parasite of the phylum Apicomplexa, Coccidia order, being an obligate intracellular protozoan that affects humans and diverse vertebrate hosts. The genus was named Toxoplasma (from the greek toxon = arc, plasma = shape) referring to its shape of first quarter or half moon and gondii in reference to the rodent where the parasite was isolated. In retrospect, the correct name for the parasite should have been Toxoplasma gundii, however Nicolle E Manceaux (1908) incorrectly identified the host as Ctenodactylus gondi. The felines, in particular the domestic cats, are the definitive hosts of the parasite, whereas warm-blooded animals are the intermediate hosts. Toxoplasmosis is one of the most spreaded zoonoses in the whole world, however the frequency of infection started to be characterized from 1948, with Sabin and Feldman, and then with other researchers, developing the first diagnostic of the disease. The toxoplasmosis affects about two million people worldwide. The prevalence of seropositive individuals for toxoplasmosis increases with age and differs depending on the population cultural patterns, dietary habits and urban or rural origin. It is known that in areas of tropical or subtropical humid climate, the prevalence is higher, once this type of weather favors the survival of oocysts in the environment. It is estimated that about 70% of the brazilian population has already been infected at some point in life. In Brazil, it was found that in every 1,000 live births, five children presented the disease. In different countries, the seroprevalence has been shown between 0% to 90% in the human population. Some countries as Thailand and Japan present low prevalence (<20%). However, Australia, Poland, UK and Belgium show average prevalence (between 23 and 53%), while Brazil, Tahiti and France present high prevalence (> 60%). The importance of the animal toxoplasmosis occurs, at first, by the fact that infected animals serve as direct or indirect source of the human infection and, secondly, by the various reproductive changes such as abortion, neonatal mortality and congenital defects consequent to the T. gondii infection, which represent significant losses in animals of economic interest and company. In the world literature on detection of anti-T. gondii in bovines, discrepant values are found, ranging from 0 to 99%. In Brazil, this variation in occurrence values is also observed ranging from 1.03% to 71.00%. Infection rates given for sheep flocks in Brazil, vary from 8% to 55%. The infection of herbivores occurs primarily through ingestion of oocysts present in food and contaminated soils. Infection of herds may be associated with the ingestion of grains contaminated by oocysts and the stabling of animals at sites containing feline manure may increase the risk of infection. Direct contact with felines had little epidemic consequence, although the presence of those infected animals indicates a contaminated environment, incurring risk to the human population and other animals.© 2013 by Nova Science Publishers, Inc. All rights reserved.