title: East Coast fever immunisation field trial in crossbred dairy cattle in Hanang and Handeni districts in northern Tanzania.
abstract: East Coast fever (ECF) causes considerable mortality and production losses in the Tanzania smallholder dairy sector and limits the introduction of improved dairy breeds in areas where the disease is present. The infection and treatment method (ITM) was adopted by smallholder dairy farms for ECF immunisation in Hanang and Handeni districts of Tanzania. This study recorded incidence rates for ECF and other tick-borne diseases (TBDs) for ECF-immunised and non-immunised cattle between 1997 and 2000. Approximately 80% of smallholder households from both sites (n = 167) participated in this longitudinal study, with immunisations carried out at the request of the livestock owners. Efficacy of ITM for preventing ECF cases in these crossbred dairy cattle was estimated at 97.6%, while that for preventing ECF deaths was 97.9%. One percent of the cattle developed clinical ECF as a result of immunisation. Since ECF immunisation permits a reduction in acaricide use, an increase in other TBDs is a potential concern. Sixty-three percent of farmers continued to use the same acaricide after immunisation, with 80% of these reducing the frequency of applications. Overall, 78% of farmers increased the acaricide application interval after immunisation beyond that recommended by the manufacturer, resulting in annual savings in the region of USD 4.77 per animal. No statistical difference was observed between the immunised and non-immunised animals in the incidence of non-ECF TBDs. However, immunised animals that succumbed to these diseases showed fewer case fatalities. ITM would therefore appear to be a suitable method for ECF control in Tanzania's smallholder dairy sector.
authors.affiliation: VetAgro Tanzania Ltd, P.O. Box 13188, Arusha, Tanzania.
authors.forename: Godelieve
authors.initials: G
authors.lastname: Lynen
authors.forename: Alma E
authors.initials: AE
authors.lastname: Yrjö-Koskinen
authors.forename: Christine
authors.initials: C
authors.lastname: Bakuname
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Di Giulio
authors.forename: Nevil
authors.initials: N
authors.lastname: Mlinga
authors.forename: Isaac
authors.initials: I
authors.lastname: Khama
authors.forename: James
authors.initials: J
authors.lastname: Hanks
authors.forename: Nick M
authors.initials: NM
authors.lastname: Taylor
authors.forename: Andrew D
authors.initials: AD
authors.lastname: James
authors.forename: Declan
authors.initials: D
authors.lastname: McKeever
authors.forename: Andy R
authors.initials: AR
authors.lastname: Peters
authors.forename: Jonathan
authors.initials: J
authors.lastname: Rushton
mesh_terms: D056810:Acaricides / Q000191:economics / Q000627:therapeutic use; D000818:Animals; D002417:Cattle; D003612:Dairying; D007114:Immunization / Q000191:economics / Q000662:veterinary*; D015994:Incidence; D008137:Longitudinal Studies; D016052:Protozoan Vaccines / Q000191:economics / Q000276:immunology / Q000627:therapeutic use*; D013636:Tanzania / Q000453:epidemiology; D013801:Theileriasis / Q000453:epidemiology / Q000276:immunology* / Q000469:parasitology / Q000517:prevention & control*; D013983:Tick Control / Q000191:economics / Q000379:methods; D017282:Tick-Borne Diseases / Q000453:epidemiology / Q000469:parasitology / Q000517:prevention & control / Q000662:veterinary*
chemical_list: D056810:Acaricides; D016052:Protozoan Vaccines