Abstract:
Phleboviruses are emerging pathogens of public health importance. However, their association with ticks is
poorly described, particularly in Africa. Here, adult ticks infesting cattle, goats and sheep were collected in two
dryland pastoralist ecosystems of Kenya (Baringo and Kajiado counties) and were screened for infection with
phleboviruses. Ticks mainly belonged to the species Rhipicephalus appendiculatus, Hyalomma impeltatum, and
Hyalomma rufipes. A fragment of the RNA-dependent RNA polymerase (RdRp) gene was identified in thirty of 671
tick pools, of which twenty-nine were from livestock sampled in Baringo county. Phylogenetic analyses revealed
that twenty-five sequences were falling in three clades within the group of tick-associated phleboviruses. The
sequences of the three clades showed nucleotide distances 8%, 19% and 22%, respectively, to previously known
viruses suggesting that these sequence fragments may belong to three distinct viruses. Viruses of the group of
tick-associated phleboviruses have been found in several countries and continents but so far have not been
associated with disease in humans or animals. In addition, five sequences were found to group with the sandflyassociated
phleboviruses Bogoria virus, Perkerra virus and Ntepes virus recently detected in the same region.
Further studies are needed to investigate the transmission and maintenance cycles of these viruses, as well as to
assess their potential to infect vertebrates.