Prevalence, seasonal dynamics and associated variables of ixodid tick cattle infestation in Gondar, northwestern Ethiopia

Abstract

Ticks are ectoparasites that impact the health and productivity in farm animals. They are also important vectors for pathogens transmitted to animals and humans. A cross-sectional study was conducted from November 2018 to April 2019 with the objectives of determining the prevalence, identifying genera and seasonal dynamics of adult ixodid ticks infesting cattle in and around Gondar, northwestern Ethiopia. Pearson Chi-square Test was used to evaluate the association of tick prevalence with explanatory variables. One way analysis of variance was used to compare mean tick density of cattle with the explanatory variables. The overall prevalence of cattle ixodid tick infestation was found to be 65.8% (95% CI = 60.0–71.2%). The effect of breed, sex, age and body condition score on tick prevalence was investigated. However, only the body condition score of study animals was found to have statistically significant effect on the prevalence of tick infestation. Monthly analysis of tick infestation showed statistically significant variation (χ2 = 36.17, p = 0.00) during the study period (November 2018 – April 2019). The highest monthly prevalence was recorded in March (85.0%), and the least in February (42.0%). A comparison of the tick prevalence across seasons showed statistically significant differences (χ = 34.10, p = 0.00), being highest (82.5%) during the short rainy season. During the study period, a total of 3796 adult ixodid ticks were collected from different body regions of the study animals. Three ixodid tick genera were identified, with the genus Rhipicephalus being the most prevalent (n = 2122 (55.9%) of the total adult ticks (3796). The overall mean tick density per host for all genera was 12.78 ticks, with a marked difference in tick density during the three study seasons. The highest MTD was recorded during the short rainy season (MTD = 18.58), (F = 19.71, p < 0.05). The present study has shown that ticks are highly prevalent in the study area. Therefore, an appropriate tick control program should be designed and implemented.