Relative importance of different ungulate species on the lifecycle of Anaplasma phagocytophilum

Abstract

Background: Anaplasmosis is an emerging tick borne disease caused by the bacterium Anaplasma phagocytophilum. Ungulate species are an important animal reservoir and therefore they play a central role in the epidemiology. Ungulate management could possibly be used to reduce the amount of infected ticks in the vegetation. To be able to properly implement this management in order to achieve this goal, more knowledge of Anaplasma in different ungulate species is needed. Part of this knowledge can be obtained by determining the relative importance. Therefore I determined in this study the relative importance of five different ungulate species with data from previous studies. In addition I looked if there is a difference in infection prevalence of hosts per geographical area. This data could be an important part to determine a different management strategy per area. Methods: I performed a systematic review with studies that included data on the measurements to calculate the host infection prevalence with A. phagocytophilum, and the measurements to calculate the infection prevalence with A. phagocytophilum on feeding ticks. I included the following host species: fallow deer (Dama dama), moose (Alces alces), roe deer (Capreolus capreolus), red deer (Cervus elaphus) and wild boar (Sus scrofa). I analyzed the data from 52 publications. Results: I found a significant lower infection prevalence in wild boar (6,57%, p < 0,05) and in addition, it has been shown that the geographical area is an extra factor in the infection prevalence per host. There is a seems to be relationship between the relative importance in feeding and the relative importance in infecting both nymphs (t = 28,52, p < 0.05) and larvae (t = 48,24, p < 0,05). Conclusion: The significant lower prevalence rate and the low relative importance of wild boar indicates that their role in the lifecycle of Anaplasma phagocytophilum is less important, and ungulate management can better be targeted at deer species. The data indicates that there is a relationship between the relative importance in feeding and the relative importance in infection both nymphs and larvae when the data of all host species was combined. As far as management is concerned, this means that if less ticks can feed from the animals, it is likely that the amount of infected ticks in the vegetation can be reduced.