Babesiacidal Drugs

Economic Importance Members of the genus Babesia occur throughout the world and may cause a wide range of clinical syndromes in most domestic animals and humans due to differences in virulence within each Babesia species. They are transmitted by hard ticks (Ixodidae) during blood meals, and may produce diseases in their hosts, which are characterized by an acute febrile reaction, jaundice, hemolytic anemia, hemoglobinuria and variable mortality. The babesiosis is of major economic importance in cattle because the majority of about 1.2 billion cattle in the world are potentially exposed to Babesia spp. because of the extensive husbandry methods employed in raising these animals. Babesia spp. infections may also occur by the frequent introduction of Babesia-free animals into Babesia-enzootic areas, and by introduction of tick vectors and Babesia spp. into clean zones. The greatest economic loss is due to Babesia spp. infections in cattle, particularly in the USA, Australia (State of Queensland), South Africa, and South America. Indigenous animals are normally protected from babesiosis in early life by premunition resulting from continuous reinfection. In regions with enzootic stability babesiasis is not a disease problem, and control measures are not necessary. In these zones calves are still protected by maternal antibodies which they had received through the colostrum. Subsequently the animals remain carriers by repeated natural infections.