Theileria, Babesia, and Anaplasma spp. in
ticks
We detected A. marginale, the cause of gall sickness, B.
bigemina, which causes redwater, and T. parva , which causes East
Coast fever in 1.88%, 0.63%, and 0.31% (estimated true prevalences)
of rhipicephaline ticks, respectively. These three diseases are major
impediments to livestock production in Kenya and SSA, causing severe
loss of production in affected animals (Wesonga et al., 2010; Woolhouse
et al., 2015). We recently found T. parva more frequently in Rh. appendiculatus (15.7% of tick pools) sampled in the Maasai
Mara National Reserve, where no Babesia was detected (Oundo et
al., 2020). The absence of T. parva in animal blood samples in
this study may be partly explained by its biology, where most of its
life cycle is found in the lymphoid system and only multiplies in RBC
for completion of its life cycle (Mans et al., 2015). Accordingly, we
found higher prevalence in ticks of the mildly pathogenic Theileria spp., T. taurotragi, T. velifera, and T. mutans than reported by Njiiri et al. (2015) in calves
in Busia, Kenya, and by Lorusso et al. (2016) in Nigerian cattle.
Nonetheless, these species can also cause theileriosis in
immuno-compromised animals. We also detected Anaplasma platys,
the cause of canine cyclic thrombocytopenia, in several pools ofRhipicephalus ticks from cattle. This pathogenic bacterium has
been reported in other studies in ticks and blood from livestock (Omondi
et al., 2017; Said et al., 2017; Lorusso et al., 2016) and recent
evidence suggests that A. platys may infect humans, posing a risk
in cases of opportunistic tick bites (Arraga-Alvarado et al., 2014;
Breitschwerdt et al., 2014; Maggi et al., 2013).