Spatial clustering of fourteen tick species across districts of Zimbabwe

Abstract

Background Ticks transmit several diseases that result in high morbidity and mortality in livestock. Tick-borne diseases are an economic burden that negatively affect livestock production, cost countries billions of dollars through vaccine procurement and other disease management efforts. Thus, understanding the spatial distribution of tick hotspots is critical for identifying potential areas of high tick-borne disease transmission and setting up priority areas for targeted tick disease management. In this study, optimised hotspot analysis was applied to detect hotspots and coldspots of 14 common tick species in Zimbabwe. Data on the spatial distribution of tick species were obtained from the Epidemiology Unit of the Division of Veterinary Field Services of Zimbabwe. Results A total of 55,133 ticks were collected with Rhipicephalus decoloratus being the most common species (28.7%), followed by Amblyomma hebraeum (20.6%), and Rhipicephalus sanguineus sensu lato (0.06%) being the least common species. Results also showed that tick hotspots are species-specific with particular tick species occupying defined localities in the country. For instance, Amblyomma variegatum, Rhipicephalus appendiculatus, Rhipicephalus decoloratus, Rhipicephalus compostus, Rhipicephalus microplus, Rhipicephalus pravus, and Rhipicephalus simus were concentrated in the north and north eastern districts of the country. In contrast, Amblyomma hebraeum, Hyalomma rufipes, Hyalomma trancatum and Rhipicephalus evertsi evertsi were prevalent in the southern districts of Zimbabwe. Conclusion The occurrence of broadly similar hotspots of several tick species in different districts suggests presence of spatial overlaps in the niche of the tick species. As ticks are vectors of several tick-borne diseases, there is high likelihood of multiple disease transmission in the same geographic region. This study is the first in Zimbabwe to demonstrate unique spatial patterns in the distribution of several tick species across the country. The results of this study provide an important opportunity for the development of spatially-targeted tick-borne disease management strategies.

Predictive Analytics of Cattle Host and Environmental and Micro-Climate Factors for Tick Distribution and Abundance at the Livestock–Wildlife Interface in the Lower Okavango Delta of Botswana

“…This was done using tick counts as input field at each crush geo-location and the index's p-value was calculated to assess whether any observed clustering of similar tick counts is statistically significant or whether it occurred by chance (27). Mapping of crushes for the season(s) with significant clustering of crushes on the basis of tick counts was done in ArcGIS 10.8.1 spatial analysis software using the hotspot analysis tool in order to identify characteristics of clustering patterns not revealed by the Moran's I statistic alone, that is, the degree of clustering for either high or low tick counts values (28)(29)(30) across the study area.…”

An ecological and epidemiological single‐season survey of Anaplasma and Ehrlichia positive ticks in Victoria Falls National Park, Zimbabwe

“…It is very likely that the tick species collected and corresponding groEL amplification data were connected to our experimental design (e.g., opportunistic host collections short study period, limited geographic range, unknown tick treatment practices). Previously, hot spot analysis of common ticks of Zimbabwe cattle identified 14 species, but only A. variegatum was shared in our study (Shekede et al, 2021). Knowing the life history of these ticks (three‐host ticks feeding on multiple host species, living multiple years, and questing during different seasons) contribute to the potential biases and limitations within this study.…”

Bovine anaplasmosis in Zimbabwe: spatio-temporal distribution and environmental drivers

“… 2019 ; Shekede et al. 2021 ). Therefore, their occurrence impacts negatively on national agricultural production as well as hindering access to profitable foreign beef markets (Guerrini et al.…”

“… 2019 ; Shekede et al. 2021 ). In Zimbabwe, the high mortality rates are linked to low dipping frequency, common in communal areas where farmers rely on government support for dipping chemicals (Shekede et al.…”

“…Knowledge of disease hotspots is important for optimal resource allocation through targeted preventive and control strategies to areas with the greatest need (Shekede et al. 2021 ; Shaweno et al. 2021 ; Ren et al.…”