Neosporosis in Argentina: past, present and future perspectives

MOORE D.P.; HECKER Y.P.; CAMPERO L.M.; FIORANI, F.; CIRONE, K.M.; CANTON G.J.

Berna

Congreso; 6th International Meeting on Apicomplexan Parasites in Farm Animals; 2023

ApicoWplexa network

Neosporosis, caused by the protozoan Neospora caninum, was first diagnosed in Argentinean cattle in the ´90. Having a national bovine stock is approximately 51 million heads, cattle industry is social and economically relevant in Argentina. Severe economic losses have been estimated in 33 and 12 million US dollars annually in dairy and beef cattle, respectively. Nowadays approx. 9% of bovine abortions in the Buenos Aires province are caused by this parasitic disease. The first isolation of N. caninum from oocysts in the feces of a naturally infected dog was performed in Argentina in 2001. Another 3 isolates (Nc-Argentina LP1, LP2 and Nc-Axis) were obtained from cattle and chital (Axis axis), respectively. Many seroepidemiological and fetal studies revealed a high distribution of Neospora-infections not only in dairy but also in beef cattle. Prevalence may vary from 5 to 80% in dairy cattle and from 2 to 50% in beef cattle without antecedents of reproductive losses. Although many attempts were done to obtain successful experimental vaccines to prevent Neospora-abortions and transmission, prevention and control strategies are, nowadays, based on the identification at the herd level of seropositive cattle and culled. Embryo transfer has been successfully used in avoiding Neospora-vertical transmission. Also, reduction of both seroprevalence and Neospora -related abortions have been achieved in dairy farmsby the use of selective breeding strategies. Neospora-infections have been also reported in goat, sheep, red deer, water buffaloes and foxes. Moreover Neospora-related reproductive losses in sheep and red deer were recently reported and could be more frequent que previously though. Furthermore, Neospora-abortions have been registered in sheep, water buffaloes and chital. Even though the disease can be easily confirmed by practitioners with the help of diagnostic laboratories, control of neosporosis is not optimal. The development of new strategies including new antiprotozoal drugs and vaccines is needed.