Spatio-temporal variation in the dipping frequency of communal cattle at the wildlife-livestock interface in the Mnisi study area Mpumalanga South Africa

Tick burden and tick-borne diseases (TBDs) in cattle have for centuries plagued most parts of southern Africa, hence the adoption of various tick control strategies. The most commonly used method of tick control has been the application of chemical acaricides to cattle through plunge dipping. Dipping frequency is influenced by factors such as disease risk, eco-climatic conditions, level of vector challenge, animal breed, vector life cycle and the residual effect of the chosen acaricide. Compulsory weekly dipping (intensive tick control) is often implemented by State Veterinary Departments as an aid to effective disease surveillance. Such intensive tick control, however, negatively impacts on endemic stability to TBDs and results in more rapid selection for acaricide resistance, especially amongst one-host ticks. A study was conducted in the Mnisi communal area (MCA), a Corridor disease (CD) and Foot and mouth disease (FMD) controlled area, situated in the north-eastern part of Bushbuckridge Municipality, Mpumalanga, South Africa. Data was collected from 16 sites (dip tanks) corresponding to 16 villages in the area. The study aimed to determine the actual dipping frequency (as opposed to the intended weekly dipping regimen) and factors influencing the dipping frequency. The specific objectives were to determine, a) the number of dipping sessions per dip tank, per season and per year b) the average proportion of cattle dipped per dip tank per session across seasons and years c) to describe the seasonal pattern of dipping frequency and d) the main reasons for variation between actual and intended dipping frequency. A longitudinal, retrospective survey was conducted, based on data obtained from 16 dip tanks of the Veterinary Service of the Department of Agriculture, Rural Development Land and Environmental Affairs in Mpumalanga Province. Descriptive statistics and multiple logistic regression was used to analyse the data. The results indicated a gradual increase in the frequency of dipping over a period of 7 years and across the 16 dip tanks. There was a variation between intended dipping (52 times per annum) and actual dipping (27 times per annum). The dipping frequency and proportion of cattle dipped varied across the seasons and years. The average dipping frequency for the study period was 27 times per annum (53%) and the average proportion of cattle dipped was 49%.There was a significant difference in the dipping frequency across the three seasons. Disruptions in dipping were noted and the main reasons for not dipping were official leave or temporary reassignment of officials to other disease control programmes and weather conditions mainly rainfall. This study creates an opportunity to discuss the impact of the findings in relation to its implications on acaricide resistance and maintenance of endemic stability to TBDs. The current dipping pattern is discussed and a strategic or less intensive dipping system is recommended.Dissertation (MSc)--University of Pretoria, 2018.Veterinary Tropical DiseasesMScUnrestricte