Tick distribution and abundance is influenced by several factors that include micro-climate and environmental and host factors. Contextual understanding of the role played by these factors is critical to guide control measures. The aim of this study was to determine the predictive value of these factors for changes in tick distribution and abundance at the livestock–wildlife interface of the lower Okavango Delta. A two-stage quota sampling design was adopted to select 30 clusters of seven cattle each for tick investigation. Tick investigation was done by lifting the tail to count the total number of ticks at the anno-vulva region during the four meteorological seasons of the year. Additional data were collected on ear tag number, location of origin, sex, age, body condition score (BCS), season of the year, stocking density, and Normalized Difference Vegetation Index values of source terrain. A random effects model was used to evaluate predictive value of the above for tick abundance. Additional mapping of tick distribution pattern in the abattoir catchment area was conducted using spatial autocorrelation and hot-spot analysis. Tick intensity of infection increased linearly from males to females (Z = 3.84, p < 0.001), decreased linearly from lower to higher BCS (Z = −4.11, p < 0.001), and increased linearly from cold-dry through dry to wet seasons (Z = 10.19, p < 0.001). Significant clustering of neighboring crushes on account of tick count was noted in the late-hot-dry season, with high tick count in crushes located along the seasonal flood plains and low tick counts in those located in the dry grasslands. It was concluded from this study that cattle tick abundance is influenced largely by season of the year and that the micro-climatic conditions brought about by the seasonal flooding of the delta have a decided effect on tick distribution during the driest of the seasons. Our study has, for the first time, profiled drivers of tick distribution and population growth in this unique ecosystem. This has the potential to benefit human and veterinary public health in the area through implementation of sustainable tick control strategies that are not heavily reliant on acaricides.

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Foot-and-mouth disease (FMD) was first documented in domestic stock in Botswana in the early 1930s and since then the country opted for eradication of FMD from all her livestock-rearing areas. A multipronged control strategy was adopted along the pathway towards eradication that initially included strategic apthisation of cloven-hooved domestic stock up to 1964, movement restriction through cordon fences and quarantine system from the 1950s, and vaccination using readily available commercial vaccines from the mid-1960s, to date. This has resulted in 78% of the country's land area being officially declared and recognized by the World Organisation for Animal Health (OIE) as FMD free without vaccination. However, the disease has remained endemic in the northern parts of the country, owing largely to co-existence of livestock and wildlife. We applied a qualitative risk analysis method in our study to assess the risk of FMD outbreak in zone 2 because of interaction between cattle and buffalo across a man-made physical barrier, southern buffalo fence, in the north of the country. The assessed risk was rated 'moderate' with moderate level of uncertainty, meaning assessment of mitigation options should be done before authorising import of cattle and cattle product from zone 2. Because of cost escalation associated with FMD controls, particularly zoning with cordon fences in the face of relentless trampling by elephants, we concluded that there is a need to revise the national goal of country-wide eradication of FMD in livestock rearing areas to a more achievable outcome for zone 2. We recommend adoption of husbandry management practices and marketing approaches that recognizes co-existence of cattle and wildlife in zone 2 as an exception to the rest of the country. Such an approach should be rooted not on geographic occurrence of FMD nor separation of the two species but on food product safety guarantees along the value chain, and we believe this to be critical for sustainability of FMD management and livelihoods in zone 2.

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