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Control of East Coast Fever
4
Parasitology Today, vol, 3, no. I, 1987
Control of East Coast Fever East Coast Fever (ECF) (Box I) is a disease of cattle in East Africa caused by species of Theileria transmitted by the brown ear tick Rhipicephalus appendiculatus (Fig. 3). In the past, E C F has been controlled by reducing tick infestations through strict short-interval acaricide application, adherence to legislation on cattle movements and quarantine, and good livestock and pasture management. However, civil unrest, illegal cattle movement, poor management and inadequate maintenance of acaricidal dips and sprayraces, acaricide resistance and the high cost of acaricides, have all combined to make this approach to E C F control less reliable. An alternative approach is through immunization. Cattle which recoverfrom the disease have a solid immunity to homologous challenge, and this has encouraged the search for a vaccine since the early 1900s. Two methods of active immunization have been extensively explored; immunization with schizont infected cells is not yet practicable, but immunization by infection followed by drug treatment, has great potential for immediate use. In this debate, Tom Dolan discusses the immunization approach to E C F control, while Roger Tatchell explains how tick control can contribute to this strategy.
I m m u n i z a t i o n to Control East Coast Fever T.T. Dolan International Laboratory for Researchon Animal Diseases(ILRAD) P© Box 30709 Nairobi, Kenya
Early attempts to immunize cattle against ECF were based on the inoculation of spleen and lymph homogenates from confarmed ECF cases using a method devised by Theiler2. In the period 1911-1914, this approach was used to immunize 283 000 cattle in the Transkei territories of South Africa 3. In the original laboratory investigation 2, this method killed 25% of treated cat-
fie but 60% of the survivors were immune. However, no treatment was then available for animals that became clinically ill, and the inoculation procedure was difficult because of the need to use the immunizing material immediately after harvesting from sick animals. This approach was therefore abandoned. Successful in vitro cultivation of T.
© 1 9 8 7 E sevpe~Science Publishers BV., Amsterdam 0169-4758/87/$0200
Parasitology Today, vol, 3, no. I, 1987
Control of East Coast Fever East Coast Fever (ECF) (Box I) is a disease of cattle in East Africa caused by species of Theileria transmitted by the brown ear tick Rhipicephalus appendiculatus (Fig. 3). In the past, E C F has been controlled by reducing tick infestations through strict short-interval acaricide application, adherence to legislation on cattle movements and quarantine, and good livestock and pasture management. However, civil unrest, illegal cattle movement, poor management and inadequate maintenance of acaricidal dips and sprayraces, acaricide resistance and the high cost of acaricides, have all combined to make this approach to E C F control less reliable. An alternative approach is through immunization. Cattle which recoverfrom the disease have a solid immunity to homologous challenge, and this has encouraged the search for a vaccine since the early 1900s. Two methods of active immunization have been extensively explored; immunization with schizont infected cells is not yet practicable, but immunization by infection followed by drug treatment, has great potential for immediate use. In this debate, Tom Dolan discusses the immunization approach to E C F control, while Roger Tatchell explains how tick control can contribute to this strategy.
I m m u n i z a t i o n to Control East Coast Fever T.T. Dolan International Laboratory for Researchon Animal Diseases(ILRAD) P© Box 30709 Nairobi, Kenya
Early attempts to immunize cattle against ECF were based on the inoculation of spleen and lymph homogenates from confarmed ECF cases using a method devised by Theiler2. In the period 1911-1914, this approach was used to immunize 283 000 cattle in the Transkei territories of South Africa 3. In the original laboratory investigation 2, this method killed 25% of treated cat-
fie but 60% of the survivors were immune. However, no treatment was then available for animals that became clinically ill, and the inoculation procedure was difficult because of the need to use the immunizing material immediately after harvesting from sick animals. This approach was therefore abandoned. Successful in vitro cultivation of T.
© 1 9 8 7 E sevpe~Science Publishers BV., Amsterdam 0169-4758/87/$0200